The primary driver behind this was the need to replace the valve stem seals.   A couple of my sparkplugs, #1 in particular, would regularly foul up.    I didn’t have a lot of visible smoke, but I did see the odd puff of smoke taking off after a period idling.   This is a pretty common problem in these engines.   Age, and lack of use cause the valve stem seals to harden and allows oil to get into the cylinders, in particular at idle.   A number of these engines have been prematurely rebuilt due to this simple issue.

It also seemed sensible to change the timing chain at the same time.    I understood that it had been done a year or so before I bought the car in 2003.    I didn’t have any evidence for this.   Removing the valve covers showed that the chain had been replaced at some point, as had the guides.   However, I wasn’t sure the age of the chain and the guides were now coffee coloured.

I started by ordering the parts I would need.    The part numbers I ordered are listed below.   I don’t guarantee these are correct for any other car.   For a lot of these parts I prefer genuine given their importance to the engine and how expensive this job is.

• Timing chain – 000 997 76 94 – IWIS (In a Febi Box)
• Timing chain tensioner – 117 050 10 11 – Genuine.  This is the tensioner with the port for air injection.   It is quite expensive.   The air injection system on my car has been disabled and it was not clear to me if I could have simply used the normal tensioner.
• Camshaft oiler tube kits x2 – 117 180 00 84 – I wanted genuine, but they are now NLA so purchased Febi.
• Chain guide x2 – 117 052 09 16 – Genuine
• Chain guide x2 – 117 052 08 16 – Genuine
• Tensioner guide – 117 050 04 15 – Genuine
• Guide pin – 116 052 21 74 – got a couple in case they were needed, but they can normally be reused.
• Left valve cover gasket – 116 016 13 21 – Elring
• Right valve cover gasket – 116 016 14 21 – Elring
• Valve cover copper sealing ring x8 – 915035 000016 – Reinz
• Valve stem seal kits x2 – 116 050 01 67 – Genuine

While I was there I also ordered some other parts I needed that will be used later, such as the drier pictured above.    I also grabbed the two pictured air hoses to be replaced at the same time as they were rock hard.

There were no major issues during the job, although my mechanic noted that the valve stem seals are much harder to do in the 107 than the 126.   There is far less room, particularly up near the brake booster.   The oil seals immediately showed why I had an issue with oil getting into the cylinders   A couple had cracked and the rest were so hard they were not sealing properly.

It would appear that Mercedes-Benz revised these seals at some point.   The new ones were rubber, whereas the old ones were a hard plastic type material.     During the timing chain job, a couple of the lifters need replacement.   Unlike during the timing chain job on my 560SEC, none of the guides were broken, but they were all discoloured.   It is not clear how many kilometres were on my chain, but the camshaft sprockets had a reasonable amount of wear on them.

After the job, my mechanic performed a compression test on my engine and he was very happy with the results, even after 313,000km.   The car runs very well now, and seems to even have a little more power.   This was quite an expensive job, but necessary if you are going to own a Mercedes-Benz v8 of this era.

In addition, during the timing chain job, I had the tensioner, guides, and camshaft oiler fittings replaced as per the parts list above.   These should always be done at the same time.

The post M117 450 Timing chain and valve stem seals appeared first on Classic Jalopy.

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.

In 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.

The 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.

The post 560SEL further maintenance appeared first on Classic Jalopy.

The photo shows the new chain in place with all new guides.   They are a much better colour than the old ones!   My timing for this repair was good as one of the existing guides was broken.   This car is now my third 560SEC, and the third one where I have sent it in to have the chain done.   In all three cases, one of the guides was broken.    This makes the engine a ticking time bomb as if the guide gets caught up in the chain on startup, it can jump a tooth and valves/pistons collide.

At the same time the valve stem seals were replaced.   The old seals were really hard and i’m feeling confident that I will no longer get the puff of smoke on takeoff.  For both of these repairs the parts are not the major cost of the job.  I had supplied the parts as I wanted to use genuine or OEM parts where possible.   I have heard the genuine guides and valve stem seals are much better than the aftermarket options and will last a lot longer.   Unfortunately the genuine tensioner is really expensive so I went with a Febi unit in this case.

As the timing chain stretches, it affects the timing of the engine.  The combination of chain stretch and wear in the upper and lower sprockets.  As the upper sprockets need to be removed, it makes sense to replace them.   The lower sprocket would only be replaced when the engine is torn down.   I was pleased to see that the engine lines up perfectly, making me think that the lower sprocket is not worn.   The three photos below show the timing marks on the two camshafts and the crankshaft.

I pick up the car early next week.   The timing chain will give me a lot more peace of mind driving the car.    I will also be able to drive the car without giving the driver behind me a foul smelling surprise.    I’m looking forward to driving the car again.

The post 560SEC Timing chain and valve stem seals appeared first on Classic Jalopy.

The parts below are all that is needed to perform this job.  On the top row from the left the first are the chain sprockets for the camshafts.   These are not strictly necessary to change but once engines are over 200,000km they are normally worn and result in timing that is slightly off.   As they have to come off to replace the guides it makes sense to replace them.    Next is the chain itself.   IWIS is the OE supplier for these engines.   It comes with a master link and the chain.    Next to the chain is the tensioner.   I was hoping to go with a Mercedes tensioner, but they are now over USD$400.   Finally on the first row is the camshaft oilers, one kit per side.   These are plastic and become hard and brittle.

In the second row, the first is the valve stem seals.   One kit per side.  These are the genuine Mercedes seals.   I also went for the genuine Mercedes guides, as can be seen in the bottom row.   I had heard that the Febi guides are not as good as the genuine Mercedes.   along with them is the gasket for the tensioner.   These plastic parts (guides and camshaft oilers) are the achilles heel of the M117 (and M116) engine, and in my opinion a design flaw.

In the next photo are some other parts that make sense to do at the same time.   Shown here are some gaskets for the valve covers to prevent leaks and the copper washers for the valve cover bolts.   When I checked the engine, the breather hoses looked very old, so I purchased new ones.

Also in this photo are some good used surrounds for the seatbelt opening.   I am missing my drivers side one – they crack and then fall out.   I also purchased a thermostat as this is a good item to keep as a spare.

For the longer term, I also purchased a new oil pan.   It looks like somebody has tried to jack my car up by the pan at some point in the past.   There is also a new grommet for the antenna in the pan.

I also purchased some brake pads to keep as spares (put away before the photo) and the wear sensors that go with them.    The little holder for the drivers sun visor is broken, so I have a replacement for that.   The module in the middle is a first gear start module, that I will enable with the switch above it.  Instead of starting out is second gear, this module allows the transmission to start in first and then upshift to 2nd at about 9mph.   This is not for for full throttle starts, mashing the accelerator will already drop the car into first gear.    The switch is to allow the module to be disabled.   This is important because in stop/go traffic or bad weather the 2nd gear start is better.

The leather in this car will need more conditioning, so I purchased some my Zymol.   I use this in all my cars that have leather interiors.

An oft neglected service item on these older Mercedes is the self levelling rear suspension.   This should be flushed and the filter replaced.   I purchased enough of the fluid to flush both the 560SEC and the 300SE.   I also purchased a filter for each car.

Both of my W126’s are missing their under-bonnet insulation pad.   This is for sound deadening and also to protect the paint above.   I will need to clean the remains of the old pads on before fitting these.   Unfortunately it is probably a while before I will get to them, but good to have them on hand for when I have the time.

Finally, an owners manual for the 560SEC.   Its not the correct one, as it is for a USA model, but it was not expensive on eBay.

The post 560SEC Upcoming Projects appeared first on Classic Jalopy.

The other common W126 rust area is under the rear windscreen.    This is also an issue in Australian delivered cars as it’s caused by rain.   Rain gets under the rear window seal causing rust.   The first evidence is that the rear windscreen starts delaminating at the corners.

As can be seen from the pictures, the rust has started under the screen.   I have seen much much worse in other W126’s.   This will need attending to before it spreads further and becomes an even bigger problem.

Some of the other W126 rust areas include around the boot and spare tyre well, underneath the car, behind the wheels, bottom of front fenders etc.

The other potential issue is the timing chain.   This is something of a design flaw.   As plastic guides age, they become brittle.   Unlike in the M100, the chain tensioner works on oil pressure which means on startup the chain is untensioned.   As the chain stretches, it flops around on startup, breaking one of the now brittle guides.  Part of the guide gets caught in the chain causing pistons to hit valves and the chain to penetrates the cam covers.   Timing chain failure has been the cause of many W116 & M117 equipped cars being scrapped over the years.

As the guides age they discolour.   As can be seen in the picture this guide has started to discolour although it has not completely gone.    It is obviously in worse shape than when I checked the condition of the guides in my 450SLC.

To check the chain the air cleaner assembly must be removed.   This was a good opportunity to change the filter.   When compared to the new one it was clearly in need of change.

As this is the high compression 560, it has a twin snorkel air cleaner.

The post 560SEC Major Checks appeared first on Classic Jalopy.

About the 450SE W116

While Mercedes had used the ‘S’ designation for their upper class cars for some time, the W116 model was the first time they used the moniker ‘The S Class’.  Since the W116, the top of the range saloon car has always been referred to as the S Class.

The W116 was introduced in 1972 and carried over a lot of the styling and running gear from the R/C107 range introduced in 1971.    Mercedes has a habit of introducing a lot of new technology in the S class and the W116 was no exception. For example ABS brakes were available later in production and there were a lot of other clever features in the car.  Many of these taken from the experimental safety vehicles of the time.

The W116 was also the first time Mercedes offered a diesel engine in the S class and the 300SD model with its turbo-diesel motor was very popular in the markets it was offered.     The W116 is probably best known for the 6.9, which was a development of the 6.3 litre motor from the 600 and 6.3, now bored out to 6.9 liters with a dry sump and standard hydro-pneumatic suspension.   These cars are very susceptible to rust, so there are now few W116 in good condition left.

The W116 was available in two body lengths, standard (short wheelbase) and Long Wheelbase with 10cm more room for the rear passengers.

About this 450SE W116

This car is a 450SE W116, meaning it has the M117 4.5 liter V8 and the short wheelbase body.   The car was purchased by the previous owner about 10 years ago, originally to provide an interior for another car.   It has been sitting in a carport for some years and looked a little unloved.    However, once the interior was removed, the car was shown to be generally rust free and the paintwork after a wash and polish in surprisingly good condition.       Therefore, the owner set about doing a mechanical refurbishment and sourced a replacement MB-TEX interior.  He also fitted brand new carpets which looked lovely.

During the refurbishment, the brakes were rebuilt, the timing chain done, replacement cams fitted, suspension checked, new dashboard and carpets fitted.      The car was put back on the road, but a bad water pump meant that it was parked again for a couple of years as other projects took priority.

Sadly, the car sat under a tarp for 2+ years. During that time the paintwork suffered badly with the clear coat lifting on both the front and back and some surface rust developing.   The photo of the car is from before it went into storage.

Why did I almost buy it?

I needed a car that could fit three child seats across the back seat, but only used 1x per week.   Therefore a pre 1986 car fit the bill because it could be put on historic registration that allows 60 uses per year.    The car would park out in the sun all day near a child daycare center, so a car with low running costs, but some body issues was ideal.

I liked that all the known mechanical issues such as water pump, timing chain had been done as well.    The iron block M117 is very long lived, if the timing chain has been done.

Why didn’t I buy it in the end?

As the car was being recommissioned, it was found that even though 18 months ago it ran great, it had lost all compression on one bank of cylinders.     This was too much work for the seller to rectify for the price I agreed to pay.   In the end, he found another buyer who would buy it in non-running condition.     The car is currently being worked on by a mechanic to get it back on the road.

The post Mercedes 450SE W116 – The car I almost bought appeared first on Classic Jalopy.

Over time the plastic guides become brittle and the chain stretches.  The most likely failure is either due to a stretched chain or brittle guide, the guide breaks and causes the chain to jump a tooth.   Best case is valves and pistons meet, causing bent valves and the chain ripping a hole through the rocker cover.  Worst case is a completely ruined engine.

I’ve heard that the chain really should be changed every 100,000km.   My car has a full service history, but it doesn’t indicate if the chain was every changed.   I had this job done on both my 560SECs (also M117 engines).   Both cars were ticking time bombs – at around 300,000km they had original chains and cracked guides.

The only way to check is to remove the valve covers.  This is not a particularly difficult job on the M117:  It just involves removing the air cleaner assembly, spark plug leads and a few other pipes.   The picture below shows the chain and one of the plastic guides.   Straight away it is obvious this chain has been changed as the link is showing.   The original chains do not have the link.    The guides did not appear worn or discolored.

I know a lot of work was done to the car about 12-18 months before I got the car – at about 230-240,000.   This would probably fit in with the condition of the chain, guides and sprockets.    In this case, the chain probably doesn’t need imminent replacement, although the correct procedure is to check chain stretch which I did not have time to do.    On various forums, I have read different things about the guides.   I have heard the Febi guides are not as good as the factory guides.   I have also read that there are uprated guides available.    I have not yet had a chance to investigate either option.

I had become increasingly concerned about the timing chain on my car.   I will need to do this job in future.   The good news is that it does not appear the engine is a ticking time bomb.

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