Guest Article: MrFrotop buys a coupe

The club guys were right about the bug. You know, the one you catch after buying your first classic Mercedes. It’s not that the W108 3.5 wasn’t enough, but after a couple of years you feel an irrational (yet somewhat justified) urge to have a Mercedes for every occasion. Rescuing all of these beautifully engineered machines from an untimely demise is a noble cause, some might argue. The passion was certainly there but in the end, you need a number of factors to align: funds, garage space and spousal approval. I had only one of those, the rest will have to align later.

I wanted a coupe I could drive regularly which had rear seats for our two toddlers, and a 450SLC seemed like the obvious choice. However, I struggled to find a C107 that I liked which didn’t have an unrealistic price tag. It’s not that the SLC prices were astronomical in 2019, but obviously the asking price should reflect the condition of the vehicle beyond a fancy respray. The C107 can have some issues which are skin deep. What might appear like an excellent exterior could have a project car lurking beneath. Perhaps I made the mistake of using Colin T’s beautiful white 450SLC as reference, and ultimately nothing I inspected came close to the condition of this car.

At this point, I wasn’t searching for a C123, but widening the Gumtree classifieds search slightly came up with a white ’78 280CE in Canberra. The W123 was one of the most successful Mercedes-Benz models ever, with over 2.7 million variants manufactured between 1975 and 1986. They were known for their unrivaled reliability and high mileage capability – which is a good thing, since this ’78 280CE for sale had over 430,000km on the clock! If you were buying anything made after 1990, perhaps this high mileage would be a deterrent. But this is a 123 we’re talking about here, and the 2.8(ish)L M110 twin overhead cam motor is known to be bulletproof. In any case the price was ridiculously low, and it even had 11 months registration left. A convincing argument emerged around driving this CE for a year, and if it dies after 11 months then at least we got to experience what a 123 was all about. My wife agreed, so that box was ticked and I arranged a bus ride to the ACT after an agreed conditional price with the owner.

78 280CE M110

Everyone has a set of non-negotiable conditions when buying a car, and some of these may differ from person to person. Perhaps an Australian delivered car is an important condition for some, or sub-200K mileage for another. For me, a good service history, an excellent interior and minimal rust are very important – the rest can be fixed and restored with time. During my brief inspection of the vehicle, I was blown away by the condition of the interior. It even had the original factory floor mats, which were in excellent condition. The dashboard was virtually crack free, and the burlwood highlights (featuring on the first series C123) were also excellent. It drove ok, but felt a bit soft in the rear (what I later discovered was Self Leveling Suspension or SLS). Overall mechanically it appeared to be good and frankly, the price didn’t justify a higher level of mechanical scrutiny. I was only going to drive it for year you see, until it dies or I find an SLC, whichever came first. With a straight body and excellent chrome work, it was obvious that this little Australian delivered coupe has been well looked after. Other than some minor rust in the bottom inside of the front doors, paintwork “patina” and some suspension squeaks, it appeared to be a good car. We did the deal and I drove her back on the 270km trek home. Perhaps that’s when the love story began. I just couldn’t believe that a high mileage car from 1978 could be so smooth, quiet and capable on the freeway. I love my W108 but the refinement of this little coupe is a generation ahead, which it actually is.

78 280CE Interior

Out of the 2.7 million 123s produced, less than 100,000 were coupes, and a much smaller number were manufactured in RHD. Not a unicorn, but not available in abundance either. The more I read about the C123, the more I realise how sought after these were back in the day. The price tag in 1978 was AU$40,700 which was equivalent to a Jaguar XJ-S V12. Despite the exorbitant premium over the sedans, new 280CEs were fetching even higher prices overseas on the black market because they were so hard to get.

Other than a missing sunroof, my ’78 280CE coupe seems to have everything else. Power windows front and rear, power steering, disc brakes, air conditioning, cruise control and SLS – as featured in other early W123 delivered in Australia, perhaps to justify the hefty price tag at the time.

78 280CE Burl

In the first few weeks, the tires brakes and suspension squeaks were sorted out and the AC was re-gassed. Later on, we replaced the fuel injectors and some minor electrical components. Changing all the engine and gearbox mounts made a huge difference to noise and vibration and totally transformed the car. The hood liner had turned to powder, and it was also replaced – we now have a clean engine bay which was free from hood liner dust. A fun “C19 lockdown” project was fixing the vacuum central locking system using some spare actuator diaphragms I had. Recently, I had the top of the rear seat (which was sun damaged) reupholstered in original MBtex. The colour being a relatively rare medium brown or “Tobacco” as per the MB colour chart. Paint wise, it turns out that a good cut and polish can do wonders. It’s now a comfy, reliable and pretty pillarless cruiser. It also seems to put the toddlers to sleep pretty quickly (thank you smooth riding SLS).

In the past year, I’ve added over 7,000km of reliable commuting on the clock. The original engine is still going strong and the transmission shifts smoothly and quietly. At the time this article was written, there was 438,755km on the odometer – truly impressive.

78 280CE

Recent enthusiast interest in the 280CE has shifted the prices upwards. It’s nice to know, but it really doesn’t matter. As you’ve probably guessed by now, I’m not getting rid of this pretty coupe any time soon. While I’m a bit precious about the W108 5-digit odometer ticking over to zero, I’m compelled to hit the 500,000km milestone in the CE. At least I can get to mount that mileage badge I bought from eBay on the front grill.

Author: John Tawadros.   John is a member of the Mercedes-Benz Club of NSW and the proud owner of a 1972 280SE 3.5 and now a 1978 280CE.   You can follow his adventures with both of these cars at his Instagram feed Mrfrotop

560SEL Stainless steel exhaust system

I hadn’t planned on doing anything to the 560SEL’s exhaust system.   However, when I was checking on the possibility of reinstating the self leveling suspension I noticed that the current system was rubbing quite badly on the drive shaft.   In addition, it did not fit well and the hangers could not align.  It was being held up with wire in places.    I have now replaced it with a new 560SEL stainless steel exhaust.

The diagram below shows the factory system.   While the Australian version of the 560 is quite similar to the USA version in many ways, it uses the standard catalyst exhaust, not the USA style.

It is a rather odd design.   the centre mufflers are generally referred to as the ‘kidney’ mufflers.    My system had been welded and patched a few times.  The kidney mufflers looked quite new, but they were not put in well, and the bends of the pipes meant nothing lined up properly.   There was also rust in the pipes between the kidneys and the rear muffler.

Instead of continuing the patch the system, I decided to replace it with a new 560SEL stainless steel exhaust system.     I wanted a system that would be more free flowing, but would still look original unless the car was up on the hoist.

The whole system was replaced from the manifolds back.   In a perfect world, I would have obtained a set of the two piece manifolds as found on my 560SEC ECE.   Those manifolds are very expensive, so I went with what I had.   There are only two joins (as seen in the picture) so the whole system can be dropped easily.  This means less chance of leaks.

560SEL stainless steel exhaust

The Australian version of the 560SEL is equipped with an oxygen sensor.   This has been fitted to a small join section behind the transmission.   The rearmost section has been painted black to match the original look.

560SEL stainless steel exhaustThe new system is much neater and I can feel an improvement in performance of the car.    There is a slight increase in engine note, but still in keeping with how a luxury car like the 560SEL should sound.    As it has been raining this week, I have not been able to test the sound at high RPM/full throttle.

With an exhaust system that no longer rubbed against the drive shaft, I was able to take the car on a longer run.   I had arranged to meet a friend from the Mercedes club for a quick catch up.  A good run for the car.    He brought his 1978 280CE W123.   As it is an early CE, it has the nicer dashboard with the burl wood and self-leveling suspension.   280CE’s are an underrated car.

560SEL and 280CE

560SEL further maintenance

Before I begin regular usage of the 560SEL there is further maintenance required.   Per a receipt I have, a new timing chain and tensioner was fitted around 20,000km ago.   This is obviously a good thing, but it was a shame that while this was done, the M117 timing chain guides were not replaced.

The guides (and ideally the sprockets) should always be replaced at the same time as the chain.   It is actually the guides that are the cause of most of the problems in the M116 and M117 engines.  A stretched chain just exacerbates the problem.

M117 timing chain guidesIn the picture above are a set of genuine M117 timing chain guides.   (bottom centre).   There are two inner guides (117 052 09 16), a left guide (117 052 08 16) and the guide rail that the tensioner pushes against.

To replace the guides, the sprokets must also be removed.   It makes sense to replace then while they are out.   I went with Febi sprokets.   At the same time the guides are replaced, the plastic camshaft oilers should also be replaced.   They are very cheap and simple to replace while the cam covers are off.   Obviously, while the cam overs are off, new gaskets (left) should be fitted.

Not related to the M117 timing chain guides, the motor mounts are completely collapsed.   I have purchased Lemforder mounts.   I recomend only Lemforder or genuine mounts.   Avoid cheap alternatives like Uro or Meyle.   Lemforder mounts are not expensive.    I also bought a transmission mount.  It seems that only Meyle is available but this is less of a big deal as it is much simpler to replace.     As well as rubber mounts, the M117 engine has two shock absorbers (in the Stabilus boxes) that are looking quite elderly on my car.   There are also mounting kits to fit them properly.

When replacing the timing chain, the distributor is removed.   I have a new cap and rotor if replacement is necessary.   If not, they will go on the shelf as spares.    The belts are looking a bit tired, so I have a new set of belts.    Finally, The car is running cool (60c above 80km/h) so there is a new thermostat to fit to the car.

I am not going to do this work myself.   The chain guides in particular are a fairly involved job.   I have the car booked in for mid June to have this work done.

As well as assemble all these parts, I also changed the air filter.   It wasn’t that dirty, but at least now I know how old it is.    As I plan to reinstate the self-leveling rear suspension, I changed its filter and flushed the fluid.   I outlined this job in more detail in another post.

Self leveling rear suspensionThe fluid should be clear, but it was coffee coloured in my car.   Not as bad as the fluid in the 560SEC or 300SE, but dirty nevertheless.   This flush also allowed me to verify that the pump is still working properly.   There would be no point putting replacement struts and accumulators in to fill them up with dirty old fluid.

All this work should make this 560SEL a really good car.   My experience is that there is always work required when you purchase a new classic car – even one that has been well maintained like this one.

May 2020 Rover P5 Coupe restoration update

I had this week off work, so I went by to see the Rover P5 restorations I have been following.    For those who are not regular readers, I sold my old Rover P5 to a gentleman who is restoring three Rover P5 Coupes and I have been calling in to see the restorations every couple of months.

The last couple of months he has been moving workshops, so the progress is based on work done earlier in the year.    My old P5 has been completely dismantled.   The new workshop does not have room for parts cars.   The parts will all go to good use and the engine is available if necessary if any of the three cars need it.

Rover P5 Engine

The engine was probably the best thing about my old car.    The body was quite rusty and the interior was very worn.    The picture above shows the cover for the valve adjustment in the block – a feature of this IOE engine.

The 1964 P5 MKIIA has the fuel tank fitted, the rear seat and parcel shelf fitted and the electrics complete.    The picture below shows one of the seats off the 1964 MKIIA (in grey) and two of the seats from the MKIIC (in cream).

Rover P5 SeatsThese seats are of a very different design to the seats used in the 1966 Rover P5 MKIII.    Those seats were modified again for the P5B, but are quite similar.  The MKIII seats look more like an ‘overstuffed’ armchair.

MKIII seats

A fair amount of progress has been made on the MKIII interior.   It was a bit dark to photograph inside the car, but the car is looking very impressive from the outside.   The Webasto sunroof can be seen at the top of the photo.   This Rover P5 MKIII Coupe is going to be quite impressive when finished.

Rover P5 MKIII

Repainting the W126 cladding

The W126 was the first Mercedes to feature plastic cladding.   I’m not sure this is the best feature of the W126, but it started a trend that would continue for many years.    The W126 cladding is attached to the car with a series of clips and consists of eight peices (four on each side) along the line of the bumper bars.   The cladding is not the same colour on each car.   Before 10/88 it was a contrasting grey, and after 10/88 it was generally a darker shade of the body colour.

This page (in German) provides all the colour codes, but basically both my 560s call for 5944 Fregatblau, as this is they grey matched with 929 Nautical Blue for the second series.   My 300SE should be 7176 Muschelgrau, but it has been painted Signal Red on both the body and the cladding.   I prefer this as I don’t think Muschelgrau goes well with Signal Red.   After 9/88 it would be 3515 Tartanrot, which is much better.

Before I owned it, my 560SEC took some minor damage on the front passengers side behind wheel.   One of the cladding pieces was damaged and the body slightly dented behind it.   The cladding piece sort of held on but used to flap about as I drove.   Not a great look.

W126 Cladding

There is slight damage on the door piece as well, but it is not so bad.    I am not in a position to fix it properly right now, but was looking for a better temporary fix.   A couple of months ago, I purchased another SEC cladding piece on eBay for this side of the car.   I also collected some additional clips during a visit to a junkyard in the USA.

The piece of cladding I purchased was not Fregatblau, so I could not simply attach it.   Luckily, Autobarn, an Australian auto parts chain will make up an aerosol can or touch up pot of any paint code for a reasonable price.   I purchased an aerosol of Fregatblau to paint this piece of W126 cladding and a pot of 929 Nautical Blue to fix a few stone chips on this car and the SEL.

After roughing up the surface of the cladding and masking off the chrome,  I applied the first coat.   In the end I applied four coats.   From what I gather, the factory used a Matte clear coat.   I could not find a aerosol matte clear so I just used the colour.   The photo of the wet paint makes it look darker than it really is.

W126 cladding

Obviously I am never going to be able to match the colour of 30 years faded W126 cladding with a pressure pack.   The aim here is to get close enough so the car still looks good and I can fix it properly in a couple of years when I take care of the rust under the rear screen.

W126 cladding

Despite all this the match is actually pretty good.   I am pretty happy with the result.  The newly painted panel looks better than the previous ones, but is not so off that it is hugely noticeable.   The chrome strip is also easy to mask off.

w126 claddingOn removing the old cladding, the body is slightly more dented than I previously thought.   It was a bit of a struggle to get the newly painted cladding to line up properly.   In particularly the top right hand mounting point is the centre of the damaged area.

W126 damaged area

I found it was easiest to insert the hooks into the top square holes first and then try and align against the white circle pieces.  It is a bit tricky as the bottom mounts can’t be seen once the top ones are in.   Considering the outlay of the entire project was minimal, I am pretty happy with the result.   I am also quite hopeful of how the pot of touch up paint will help remove some stone chips, particularly on the panels below the headlights.

W126 claddingI am hoping that once I drive around, the new piece will remain in place and not continually coming loose like it was previously.   It certainly seems like it is holding on much better.

Planning to reinstate the W126 Self-leveling suspension

After driving the 560SEL more I have decided to reinstate the W126 self-leveling suspension.   I am probably one of a very small group of people who is putting this system back after it is removed.   A 560SEL should drive really nicely, but the current springs and shocks make the ride like an unladen ute over rough surfaces.   As a contrast my 560SEC has an excellent ride.

The current system was put in by Pedders, a local suspension chain.   On speaking to a few people, I have discovered that the spring/shocks they put in are not really suited to the car – they are too harsh.   So either I source proper Mercedes springs from a non-SLS car and Bilstein shocks, or re-instate the W126 self-leveling suspension.   As this car is so original, I plan to put the self-leveling back in.   I hope I don’t regret this, as the struts are now NLA, but there is still used stock.

The first step is to make sure that the system can still be re-activated.   On my first check, I verified that the fluid reservoir is still in place and contained fluid.   The accumulators are also still there.   Today I had a closer look which is very promising.    The hydraulic lines have been capped off at the accumulators.    The fluid is dirty so I will flush it over the next couple of weeks.

W126 self-leveling suspension

The leveling valve is also present and looks in good shape.   All that is missing is the control rod that joins it to the sway bar.   This is quite a cheap part.

W126 self-leveling suspension

From my research, it would appear I need:

  • 2x Self-leveling struts:   A116 320 45 13
  • 2x Accumulators.   Genuine or aftermarket.
  • 2x Hydraulic lines from strut to accumulator:  A201 997 08 82
  • Control Rod:    A123 320 14 89
  • 4x Rubber buffers:  A114 326 00 68
  • 2x Springs:  A123 324 06 04
  • 2x Spring pad: A115 325 22 44
  • Various nuts and washers etc.

Once completed, I hope to sell the current springs and shocks to somebody who wants to remove the system and likes a harder ride – for example a bash car.

While I was under the car, I had a closer look at everything.   The car is very clean underneath.   At some point the kidney mufflers have been replaced.  The bends are all wrong which is causing a part of the system to rub against the drive shaft.    I will need to sort this out quickly.

Drive shaft

This also causes the rear muffler to be out of alignment.    The differential mount looks brand new which is a bonus.    There is also an oil leak out of the sum level indicator.    Various suspension bits look like they have been changed at some point which points to the regular maintenance the car has received.

While I was under the car I also replaced the steering shock which had nearly reached the end of its life.   I had a spare one on hand.

steering shock

450SLC Battery tray

I had not driven my 450SLC since early march due to the COVID19 lockdown.   When I first started the car the battery seemed quite weak.   After a drive, I put the car on my Ctek charger.   The charger showed an error where the battery will would not hold a charge.   This was confirmed by my Solar battery tester.   The recondition mode helped a bit, but ultimately the battery is almost 8 years old.

I probably would have tried a bit harder with the reconditioning if it wasn’t for a 30% off sale on DIN batteries at Supercheap auto.    It seemed like a good opportunity to replace the battery with a new one.    The SLC calls for a DIN65L size.   The Century battery I purchased has a 660 CCA rating which is better than the 600 rating of the NRMA battery it replaced.

The SLC  battery is easy to remove.   The battery is held down with a bracket.   You’ll need a 10mm deep socket and a long extension to easily remove it.   With the battery removed, I was able to see the condition of the 450SLC battery tray.    Over the years leaks from various batteries had caused the battery tray to develop surface rust.   It seemed a good opportunity to repair this.

450SLC battery tray

The 450SLC battery tray is held down with four bolts that can be removed with the same 10mm socket.   Once it is removed it is a simple matter to clean it up with a wire brush attachment on a drill.   Unfortunately the SLC was blocking in the other cars so I needed to make a quick job of it.     The battery tray cannot be seen once the battery is installed, so the objective was to reduce rust rather than cosmetic.   Still the wire brush attachment cleaned it up rather well.

450SLC battery tray cleaned

The picture is not great as I was doing the job at night and I only had a mobile phone to illuminate.    It showed that the rust was just surface rust and the battery tray was in otherwise good condition.   In the ideal situation, I would have used some turps to clean the battery tray after this.   I didn’t have any so just blew the dust off it and used some rags.   After this most basic cleaning I primed the surface.   I went with a separate primer as I thought it would be more durable than a paint and prime.

450SLC battery tray

Once the primer had tried, it was time to apply the top coats.   My 450SLC battery tray was starting to look pretty good again!    There is some grit in the paint where my cleaning job wasn’t quite up to scratch but overall I am pretty happy.

450SSLC battery tray

Once I let the paint properly dry, I cleaned the threads.   it was easier than masking them off, especially as I didn’t have tape on hand.   I had a cheap tap and die kit I purchased at Harbor Freight in the US which came in handy.

The other advantage of removing the 450SLC battery tray is the ability to clean underneath it.   There was a fair amount of dirt and debris that would be impossible to clear without removing the tray.   There was also a low point where a bit of surface rust had formed.   I treated this while i was at it.

450SLC battery tray

Finally, a new battery was also an opportunity to fit an attachment for my Ctek battery charger.   I didn’t do a full disconnect switch like on the 250SE but the attachment makes it easier to connect the charger.   For some reason the Ctek attachments have really small eyelets so I cut those off and crimped in bigger ones that I could attach to the battery terminals.

450SLC battery charger

I always write the month and year I replace the battery on top to quickly see its age later.   The battery I was replacing was from 2012.

Which is the slowest W126?

Many people are interested in which cars are the fastest, but perhaps a more interesting question is which is the slowest W126?  There were a plethora of W126 models offered from 1979-1991 and not all of them were particularly fast.

For the purposes of this test, I have assembled some contenders, based on data from www.automobile-catalog.com.   This comparison assumes the cars are in as-new condition.  Obviously a car with low compression and a bad transmission is going to be slower.

Here are the contenders:

280SEL for the Swiss market

The Swiss market had very similar emissions laws to Australia, Japan and the USA during the early 80s.   The result of this was that the injected M110 engine was reduced to 118KW.   The big difference is that unlike Australia where the 280SE was offered, in Switzerland the heavier 280SEL was made available.   Our test car is from 1983.    These emissions laws increased the fuel consumption at the same time as blunting the performance.

Speeds are very low in Switzerland and the cars were probably used for chauffeur duty, meaning the impact other than fuel consumption was probably irrelevant.

380SEL for North America

The USA emissions laws had a profound impact on the 380SEL.   So much so that it is incredible to see a V8 in this line up.   Mercedes also persisted with the 2.47 rear axle ratio, likely because of the CAFE fuel consumption regulations.   To add insult to injury, these early cars were equipped with a single row timing chain that could break without warning.     North American models also came fully equipped resulting in the lowest power to weight ratio of any petrol W126.

Our test car is also from 1983.

280S

The 280S was the entry level model of the W126 range.   I understand it was largely sold in countries with poor fuel and where it may be hard to find people who could service a fuel injection system.     It it has the lowest power and worst fuel consumption of any of the cars tested.   However, it is lighter than some of our other contenders and has a shorter rear end ratio.   Our test car is from 1985.

I used to see a few of these during the 90s as private imports in Australia.   It has been years since I have seen one.

1985 300SD North America

The 300SD is a very popular car because of the incredible longevity of the engine and its great fuel consumption.    It is almost unfair to compare it to the other cars for this reason.   However, it is the slowest W126 by a fair margin.   It is just that it has so many other redeeming features that still make it a great choice if you live in North America.    The photo below is of a car that I saw in a junkyard while living in America.  I still have the owners manual.    Our test car is from 1985, as this year had the tallest rear end ratio.

Slowest W126

260SE Catalyst

The 260SE replaced the 280S in the line up.   It is most popular in countries with high taxes on engines with larger displacement.    Despite its smaller displacement it is the fastest W126 in our line up.    Our test car is from 1991 and is fitted with a catalytic converter, as many from the series 2 range were.

1987 300SDL (USA)

The second generation diesel engines were far smoother and more powerful than the venerable OM617.   They also had much better fuel economy.   The only downside is that they are not quite as robust.   They can still go big mileages, but the heads have been known to crack.

These are still an excellent car and in my mind the most desirable on the list.   There is a great video by Pierre Hedary that is worth watching.

Conclusion

While technically the winner of this challenge is the 300SD, the real winner is the 380SEL (USA).   The diesels are a trade off between performance and fuel consumption/longevity.   It is incredible that the performance of the 380 suffered so much due to emissions.    It is probably why these cars are now rare in the USA – once the second generation models came out there was really no comparison.    The only first generation model that is still common in the USA is the diesel, as a result of its cult following.

None of these cars are bad, in some ways this is a particularly silly test.   But it is interesting to compare the different models and work out who should be crowned the slowest W126.

Car1983 280SEL (CH)1983 380SEL (USA)1985 280S1985 300SD (USA)1991 260SE Catalyst1987 300SDL
Weight (kg)159017151560171015701740
Power (kW)11811611592118107
Torque (Nm)224266223250220264
Power/Weight (watt/kg)73.967.373.753.875.261.3
Rear end3.462.473.462.883.462.88
Est Top Speed (km/h)196188195180206195
0-100km/h (s)11.811.711.614.910.612.9
0-1/4 mile (s)17.918.417.819.517.118.5
Speed at 1/4 mile126120127115129120
Overtaking speed (80-120km)9108.911.28.210.3
City fuel consumption16.4-19.715.3-18.418.5-22.211.4-13.715.8-198.9-10.7

Mercedes W126 buyers guide

I’m a big fan of the Mercedes-Benz W126.   While it might not have the grandeur of the 60’s models, they make a really usable classic.   The W126 can even be used as a daily driver.   It still has the feel of a classic Mercedes-Benz but you get safety features like ABS, good air conditioning and reasonable fuel economy.  When they are looked after they are a a very reliable car that is a delight to drive.   I’ve now owned five of them over the years, mostly as daily drivers.  Prices are still very reasonable.  There are a few other W126 buyers guide articles out there, but I have found most of them to be superficial or focused on USA models.

W126 buyers guide

The model range is quite complex and the car had the longest production run of any S-Class meaning there is a whole range of cars to choose from.    There are three basic body styles:  the standard wheelbase saloon, long Wheelbase saloon and the coupe.   Generally the mechanical specification was much the same between the three body styles in any given year.    This W126 buyers guide attempts to outline some of the key considerations in choosing a W126.    The picture above shows all three body styles – a 1987 560SEC, a 1986 300SE and a 1987 560SEL.

The W126 also had two main series.   The first series was produced for model years 1980-1985.   The second from 1986-1991.    In addition, there was an interior refresh for the 1989 model year.    The difference between the series 1 and series 2 car is more lots of small improvements rather than a major overhaul.   The only big change was the phase out of the venerable M110 DOHC six for the new M103 SOHC six.   The M103 was easier to make pass emissions.

This W126 buyers guide is not specific to any one country, although it does focus more on models available in Australia and ignores the diesel models found only in North America.  For specific details about the models sold in the Australian market, see this article.

Which is the best W126 to buy?

The condition of the car is far more important than the model.    A 280SE in well maintained condition is a far better car than a tatty 560SEC.    The tatty car will cost you more to run and will never be as good as nice one no matter what you spend on it, unless you do a full restoration.   It will also dive like a truck and constantly annoy you with all its problems.

The first thing to look at is rust.   The W126 does not have the propensity to rust that the 70s model do, but there are a few areas to look out for.   The first is under the rear window.    When you open the boot, look under the rear screen.   I’ve seen cars that on the outside look great, but they are so rusty here that you don’t even need to put your head into the boot to see the major rust holes around the boot opening.   This is here in Australia, where rust is not the problem that it is in Europe or north America.

If there is no obvious rust, look up underneath through the openings in the sheet metal.   A small amount of rust is fixable, but if there is major rust here, walk away from the car.    The window seal gets old and lets water in.   If the car has not been parked in a garage or carport, it will probably have rust here by now.   The picture below shows minor rust breaking out in this section on my 560SEC.  The coupe is more susceptible, due to the angle of the rear screen.

rear screen rust

You’ll also want to look under the car, especially in the wheel wells.  In the front you can get rust where the guide rod bushings are, and both front and rear where the wheels flick up dirty water.   The front guards can rust near where they touch the bumpers on either side, just in front of the wheels, as can the wheel arches.  This is illustrated below.

Front guard rust

There are still enough good W126’s out there that there is no point messing with a rusty car.

Next is overall mechanical condition.   These cars are reliable when properly maintained, but a tired car with a smokey engine can be an expensive proposition to put right.    You’re also going to have to budget a fair amount for deferred maintenance on a car that has no service history.   You will want to see evidence of proper care of the car, at least over the last couple of years.

Do not neglect the interior as well.   Many interior parts are NLA, so you’ll need to resort to used parts if you want to properly sort it out.

Are there any models to avoid?

As outlined before, condition is the most important factor, but that being equal there are a few models I would avoid.    The first is 1981-1983 380SE/SEL/SEC originally sold in North America or Japan.   These cars had a single row timing chain when new and were so detuned they could hardly pull the skin of a rice pudding.    Despite what you read on the internet, the models sold in other countries did not have this problem.

I would also avoid cars equipped with ASD/ASR/ASR II, which was Mercedes first attempt at traction control.    This was available as option during series 2 production, but much more common on 1990 and 1991 cars.   If this system fails, the car is not drivable and it can be very expensive to set right.   The W126 does not need traction control with its tall gearing and second gear start.   ASR cars also can’t have a limited slip diff, which is otherwise standard on the 560.  It is easy to tell if a car has ASR as there is a little indicator in the middle of the speedometer which lights up if the wheels spin.   It looks like a small black square when not lit up.

Finally I would not bother with the 280S or 260SE.   Unless the car is a time warp, or has sentimental value they are underpowered.   They are also rarely seen these days.

It is also worth looking very suspiciously at modified cars.    There are few modifications that improve a W126.  The w126 wasn’t a clean sheet design, it was an evolution of the W116, further refining the concept.  Especially by the series 2, these were highly refined cars with a good balance between comfort, performance, handling etc.

It is surprising how many cars out there have been fitted with big wheels and/or lowered.   I’ve driven a few of these and it does not make the car ‘sporty’, it just means dead handling, tramlining and more unsprung weight.    Often these wheels have the wrong offset impacting the steering and suspension geometry.   I’ve bought two cars that were unmodified besides big wheels and the difference in the driving experience when they were removed was amazing.   The W126 should have a comfortable and supple suspension.  These modifications also increase suspension wear.

You can sharpen the W126 handling with 16″ wheels in the right offset and HD shocks, but too much and the ride is ruined.   The W126 is a big comfy car, not a sports car.    They are surprisingly tossable when set up right.  I also think the stock 15″ wheels on the series 2 cars work really well on a series 1.

Modifications also include LPG conversions.     Many of these were poorly done and don’t work well with the fuel injection these cars came with.     I’ve seen some shocking conversions over the years.

Series 1 or Series 2?

The series 2 cars have a number of nice improvements over the series 1.   These are priced into the values of the car and a series 2 is often worth double that of a series 1.   This price difference can make a nice series 1 car a better buy overall.   The Series 1 also has the M110 engine which is probably the most robust.  This and the other engines will be covered later in this W126 buyers guide.    It is far better to buy a nice series 1 car than a tatty series 2.

The main differences on the series 2 cars (outside the engines) are as follows:

  • Bigger brakes.  These do make a difference in the stopping power of the cars.
  • 15″ wheels.   I find the ‘manhole cover’ wheels go particularly well with these cars.
  • Tilting function on the sunroof.    This is a nice improvement, but adds maintenance as the tilting arms break.   Button is now near the exterior light.
  • Memory seats.   The earlier ones did not have the memory function.
  • Smooth body cladding vs ribbed.    This is just a visual change.
  • Improved window switches.     The older ones show wear very quickly.
  • Paint Colours.   Generally the series 2 colours were more conservative and buyers eschewed the more interesting ones.
  • Improved climate control.    Minor improvements, which also add complexity.  There is now a control unit for the compressor for example.
  • Interior update from late 1988.

The late series 2 cars (89-91) have a different interior.   Most people prefer it although I don’t like the design of the update door cards.  The updated interior is known as the ‘soft’ leather.  Having owned both, I didn’t notice it being any softer but the seats and door cards are of a different design.  The seat design is far more modern – no long pleated sections.   There is also a provision for more speakers in the doors if the right options are selected.     In my view this interior change is a matter of personal preference.   These cars do have a small price premium over the earlier interior.

There are a lot of minor changes that are not material to the enjoyment of the cars that I will not list out here.     In particularly the electrics changed quite a lot.

The series 2 cars are also more likely to have more options fitted.   For example, Airbags were available in series 1, but not common until late in series 2 production.     This means the series 2 cars are generally more complex than the series 1 cars, especially in the later years.     You’re more likely to find a car with MB Tex, no sunroof, manual seats etc on a series 1 car than a series 2.  It was during W126 production where Mercedes-Benz started to go from more spartan, well engineered cars to fitting luxuries.      Even inside series 2 this was the case with a 1991 300SE probably having more gadgets than a 1986 560SEL.

Which body style?

The W126 was offered in three body styles.   Coupe (SEC), standard wheelbase (SE) and long wheelbase (SEL).  The diesel models are known as SD and SDL.  The SEC is a four seat car and the rear seats are suitable for occasional use by adults.    It has the shortest wheelbase and the sportiest feel of all the cars.    It also has a different grille treatment with the front looking more like an SL.   The coupe is generally valued at 3x that of a comparable saloon and was only offered with v8 engines.     There are a lot of coupe specific interior pieces which are much harder to find.  The headlining in the coupe also starts to sag, a problem not shared with the saloons.

The two saloons differ in that the long wheelbase cars have 140mm of extra legroom for the rear passengers.    The size of the S class has generally grown over the years, so a standard W126 is actually longer than the long wheelbase W108 or W109.    The SE has enough room for adults to be comfortable in the rear.    The long wheelbase cars mean they can really stretch out and will be comfortable on long road trips.  The picture below shows the legroom in a LWB car with the drivers seat set for a very tall driver.   In this case the power reclining seat is in recline mode.

W126 Buyers Guide: LWB rear seat room

The extra length of the LWB cars is quite noticeable when parking but not apparent during normal driving.   It is quite a long car at 5160mm and may not fit in some garages.   It is generally easier to find the bigger engine cars with a long wheel base and the smaller engines with a short wheel base.  I prefer the short wheelbase cars, but I prefer the bigger engines more.

What about the engines?

Outside the north america only diesels, there were four main engines offered in the W126.   The M110 and M103 straight sixes and the M116 and M117 V8s.

The sixes

The M110 was offered as the 280S, 280SE and 280SEL from 1980-1985.    The 280S was equipped with a carburetor and is now rarely seen.    The 280SE however, was the most popular W126 sold.   The M110 is the most robust engine of the line up.   Assuming proper maintenance the head will probably have to come off at around 350,000km, but the bottom end is extremely robust.    The earlier cars had a York A/C compressor which is power hungry, but rebuildable.   1984-1985 went to a rotary which was more efficient.     This engine is probably going to be the most cost effective even if it is a little thirsty as all things being equal maintenance is likely to be lower.

The m110 did not fare well in markets with strict emissions laws the power losses were considerable.    This includes Australia, where I live.   Locally delivered cars can be a little slow but private imports are quite lively.

The M110 was replaced by the M103 for the 1986 model year.     It’s major improvement was that the emissions version hardly lost any power.    It was offered as the 260SE, 300SE and 300SEL.    The 260SE was sold in countries with punitive taxes based on engine displacement.    I have only seen one example.   Most of these cars were the 300SE or SEL.

The M103 works best in an earlier model with few options and light weight.   My 86 model is such a car and feels more lively around town than a 420SEL.   The M103 needs to rev and the 300SE is geared with this in mind.      The M103 is not as robust as the M110 and is likely going to need a head gaskets and valve guide at around 150,000km.    The m103 cars work well as a city car especially if you’re willing to rev the engine.  The picture below shows an M103 in a 300SE.   The M103 cars are a lot lighter than the M110 cars.

M103 Engine

Overall the sixes cost far less to own than the V8s, but that saving is not in petrol consumption.  Unless you drive like you have an egg under the accelerator, there is not much difference in consumption between the six and the eight.  In some cases, the eight can actually be more efficient than the six because it does not have to work very hard.  In any case, petrol bills are generally a small part of W126 ownership unless it is used for big mileages.

The V8s

The v8’s were the M116 and M117 engines.   The M116 and M117 are basically identical except the M117 has a taller block, giving a longer stroke and hence more displacement.    In the W126 only the alloy versions of these engines are offered, the 3.8 and 5.0 in the first series and the 4.2, 5.0 and 5.5 in the second series.

In both cases these engines cost significantly more than the sixes to own.   The difference is not in fuel but maintenance.    Every 100-150,000km the V8s require the timing chain, chain guides and camshaft oilers to be replaced.   The chain guides are made from plastic and once the chain starts to stretch, it can break a guide.  The broken guide can cause the chain to jump a tooth causing valves to hit pistons.    Many v8 w126’s have been scrapped due to this failure as the cost to rectify is more than the value of the car, unless the owner does the work.

Doing the preventative maintenance costs a couple of thousand dollars and if you buy a car without evidence of this job being done, it needs to be ASAP.     This failure can happen without warning.     In addition, at around 350,000km the heads are likely going to need to come off to do valve guides.   The cost to remove and machine both heads is significant.   The alloy block also means extra care re-fitting the heads.  This job can sometimes be delayed if the engine is well maintained by just fitting valve stem seals, but the guides do wear and will have to be done eventually.

If this maintenance is carried out then these engines can run forever.  There is no difference in maintenance cost between the M116 and M117 and many parts are shared.    If you’re buying a V8 at around these mileages and no evidence of the jobs done, it should be factored into the purchase price.

The picture below shows an M117 560 having the timing chain and guides done.

W126 buyers guide - M117 Timing Chain

The engines of the second series are improved from the first.    More detail can be found here on my article on the 560 engine.  The EZL (ignition module) on the later engines is a bit more problematic and can fail.   It can be difficult and expensive to find another one.    They can be rebuilt.

The all alloy V8s as found in the W126 are significantly more fuel efficient than the iron block V8s as found in models like the 107 and 116.

Other considerations

The W126 climate control works really well when it works.   When it doesn’t it can be very expensive to fix.   The parts are expensive and the system is complex.    If the system is not working, then it will likely cost thousands of dollars to put it right.    There are a number of articles on this site of my work to get the system reliable in both my 300SE and 560SEC.  By now most cars will need new vacuum pods to control the air flaps.   There is a lot of labour required to change these.   It is easy to tell if they are needed as the air will not come out of the vents that it should.   Compressors and climate control units are not cheap either.

Many W126 were fitted with self-leveling rear suspension.   This system is very reliable, but if the ride should become harsh,  the accumulators are likely dead and should be replaced ASAP.   The accumulators are not very expensive, but the struts are now NLA.   Driving around with bad accumulators puts a lot of stress on the struts.    Here in Australia, it looks like all W126 models were equipped with self-leveling.   Do not take the car to a regular suspension place or mechanic that does not know the system.   They will want to rip it out, at a far higher cost than simply fixing the very reliable system that is already there.

The odometers in these cars are known to fail.   It is a very easy fix, but neglected cars are left with broken odometers for years.   A broken odometer generally means that the car is not serviced properly as the service intervals are not tracked.   An owner who is on the ball will fix this quickly.   It also means that the number on a W126 odometer is completely meaningless unless backed up by service history.   Not only do they fail but it is laughably easy to wind them back.

The plastic radiators used in the W126 have a weakness where the neck can snap off.   There is an upgraded version now available with metal reinforcement in the neck, but some cheaper versions do not have it.   These engines do not take kindly to being overheated.   The driveshaft flex discs can also wear – particularly in the V8s.   If they look in any way cracked or perishing, they must be replaced.

The transmissions (The 722.3) offered in these cars is robust and shifts well.   They all start in second gear unless you manually select 1st in the shift gate.   You should be able to feel the shifts and the car will move to top gear quickly.   The fluid should not be too dark or have a burnt smell.   These transmissions are sensitive to fluid level and as they age leaks can mean they are run below the minimum fluid level eventually causing damage.   If they are maintained well they will eventually need a rebuild – the sixes first as they have to shift more.    For the 1989 model year the transmission on the V8’s received some internal improvements.

Many cars were fitted with after market ‘chrome’ wheel arch trims.   These were not fitted by the factory.   They can trap moisture behind them casing rust in the wheel arches.   Where a car is fitted with these, it is important to check in behind the wheel arches for rust.

At least here in Australia there is a stigma against privately imported cars.    Now even the newest W126’s are approaching 30 years old, this makes little sense.     How the car is looked after is much more of a determinant of condition than where it was originally sold.    I’ve seen rust free privately imported cars with full service history and terminally rusty Australian cars with no history.    It is more important to inspect the car correctly than worry about its origins.     Nobody services a w126 at the dealer anymore, so dealers turning their nose at the car is of no consequence.      This was also the case when I lived in the USA.    There is also just as much chance as a local car having a wound back odometer as an import.

In both cases (Australia and the USA), the privately imported cars generally offered stronger performance and a more interesting set of options.  The same care needs to be taken to check the condition given the age of the car.   The website www.datamb.com is a good resource for checking the origins and options on any W126 after 1983.

The 5 most common models

There was more than 20 W126 models offered for sale.   This W126 buyers guide reviews some of the most popular.  The advice for the coupes is pretty similar to the saloon with the same engine.

280SE (1980-1985)

The 280SE is the cheapest way of getting into W126 ownership and assuming a good example probably has the lowest ownership costs.    The M110 engine is bullet proof.   Many of these cars will be equipped with MB-Tex interiors and fewer options than later models.  Simpler can be better!   The Australian versions can be a little sluggish off the line, but go well once revved.      The value of these cars has been low for years, so avoid neglected or tired examples.

380SEL (1980-1985)

The 380 offered significantly more power and the LWB version was quite common with this engine.   Avoid LWB versions that did hire car duty.  Many of these cars were white.   The Australian versions had a 3.27 rear end so they are surprisingly quick off the line.   Likely to have far more options than a 280, for example a power rear seat in a 380SEL.      Very early 380s had a different engine that was more powerful, but these cars are now very rare.  Can take a while to find nice cars, but they are worth a look when they come up.

It is still common to find 380SELs with a basic spec like manual seats, plastic hubcaps and so on.   These can be much simpler cars than the later ones.    the 380SE was also sold but is not as common.

Ignore information on the internet about USA models unless you live there.   The engine with only 115KW and a single row timing chain was unique to North America and Japan.

300SE (1986-1991)

The 300 is probably the best city car of the line up with lower ownership costs than an V8 and good performance in the city.    The engine needs to rev to get the best out of it.    The cars from the first couple of years tend to be quite spartan – in contrast with the later cars that are often optioned right up.   Can be a good buy as they are less valuable than the V8 cars.     The picture below shows an early 300SE with MB-Tex, manual seats and no sunroof.    The power difference between emissions versions as sold in Australia, USA etc and private imports is quite small.

W126 Buyers Guide

420SEL (1986-1991)

The 420 is the efficient highway cruiser of the bunch.   It has a very tall rear end ratio which makes for very relaxed cruising and surprisingly frugal petrol consumption.    This leads to the inexplicable situation where the emissions 420 (as sold in Australia, Switzerland, Japan and the USA) feels slower than the 300 around town, but is much more fuel efficient.  It is also smooth and quiet whereas the six likes to rev.   On the highway the torque of the v8 comes into its own.    These cars have survived well and there are normally nice ones to choose from.

Here in Australia, these cars came standard with many options ticked, so there is little difference between a 420 and a 560 other than the engine.  Things like automatic climate control, power seats, self-leveling, alloy wheels, sunroof, leather steering wheel and more were all standard.   In other markets that was not the case, so privately imported cars are less likely to have automatic climate control, self-leveling and other things that were standard for Australia.   Non-emissions cars also got a useful power boost in 1988 due to a higher compression motor.

560SEL (1986-1991)

The flagship of the series.   Effortless torque both in town and on the open road.   There is a penalty at the bowser, but the engine moves the car around so effortlessly that it is not as much as you would think.  In Australia, the main difference over the 420 other than the engine was the reclining rear seat, fanfare horn, dual snorkel air cleaner and limited slip diff.  Not nearly as common as the 300 or 420 as the AUD$50k price difference when new was hard to justify.  In today’s market there is only a small premium over the 420 which in my view is worth paying.   It will just take longer to find one.

Generally when doing a VIN search the options list on a 560 will look really small.    That is because most of the options were standard from the factory.   On the other models this was not the case.  You could even order a 420 or 500 with next to no options if you wanted in Germany.   The local distributors like MBUSA and MB Australia ordered their models with many options to justify the prices in the market.

The emissions version with 180KW was sold in Australia, the USA and Japan but other markets got more powerful versions.    The picture below is my 1987 560SEL.

My 560SEL

The ultimate daily driver

While these cars are super rare in Australia, and I have not driven them, I contend that the ultimate daily driver in the W126 range would be a late (1988+) 420SE or 500SE with the high compression engine.   These cars were not sold new in Australia and only a very small number have been privately imported.

The 500 in particular has 195KW in this specification.   It is coupled with a 2.24 rear end so I would fit a first gear start relay.

Conclusion

The W126 may be one of the most usable classic Mercedes available.    They offer a comfortable smooth ride, classic looks and a car from a time when comfort and quality was more important than gadgets and lap times.

The W126 was a very expensive car when new and is not a cheap car to maintain today.   They are simple enough to work on yourself, and the factory manuals are well worth the investment.   There will be no depreciation, so you will end up with a car that will last forever if properly maintained and drive better than many new cars on the road.     I drive a lot of modern rentals and am always happy to come back to my W126.   I also find myself moving my wife’s 2007 Mercedes out of the way to drive the W126.

Citroen DS Battery

I’ve known the battery was going out on my Citroen DS for a while.   I had to start it on the jump pack after only a few weeks of inactivity, and my Ctek charger started to indicate it could not hold a charge.    The existing Citroen DS battery had served me well for about 6 years.  I like to get the biggest battery I can possibly fit in the space allocated.   They last longer, and work better especially on a car like the DS which can be a slow starter with its mechanical fuel pump.  The current battery didn’t take up all the space in the battery mounting frame.   This left room for something bigger with a bit more juice.

The current battery was a Super Charge MF50 Gold.    Its dimensions were 230mm long, 170mm wide and 180mm high (not including terminals).    My estimates from measuring the frame, its attachment points and the tray was that I could accept a battery that was up to 263mm long, 175mm wide and about 200mm high.

I spent a lot of time researching various battery sizes.   While there is some logic to the model numbers in terms of explaining the features of the batteries, I could not decipher the various sizes.    I spent a lot of time researching various battery sizes including the various recommendations from parts suppliers, manufactures and so on for the Citroen DS.   In the end, the best fit I could find was the Century NS70X MF.   The NS70 part of the model name refers to the size.   That is 259mm long, 171mm wide and 202mm high.   This increased size provided a significant capacity improvement – from 600 to 720 CCA and 60 to 85 AH.

Citroen DS battery

As can be seen in the photo above, the battery fits almost perfectly in the Citroen DS battery frame.    The battery was not cheap, at $280, but I expect it to last a long time.   There is a very similar NS70LX MF.   The L means the terminals are on the other side.   You don’t want that one.

At some point I plan some upgrades to the wiring around the battery.   There are all sorts of auxilliary wires coming off the positive terminal.    Some of them have in-line fuses, but not all of them.    I plan to fit a bused fuse box with a single wire from the positive terminal to feed the headlight relays, radio and cooling fan.    I also plan to add a relay for the driving lights.   Basically that would mean a fuse for radio, fan, low beam, high beam and driving lights.   The fuse box would then feed the existing relays that can’t be seen to the left of the battery.    While I am there I will also fit a better disconnect and Ctek charger port like I did for the 250SE.

Once I had removed the old battery I gave it a quick test on my battery tester.    Only 184/600.   No wonder it was struggling to start the car.   In addition, it was starting to bulge on the sides.

Citroen DS battery

As a comparison, the new Citroen DS battery is registering better than spec: 746/720.

Citroen DS battery

I tried what the Ctek battery recondition can do to the old one.   My experience is that it can bring back batteries that are a bit tired, but cannot do much with a battery as far gone as this one.   That was the case again as all it was able to do was bring the CCA up to 200/600.