Cocomats for the 250SE Cabriolet

I’ve owned my 250SE almost ten years and always had a mind to replace the cheap rubber mats with Cocomats.    Today I fitted the Cocomats I bought as part of a group buy with a few friends.    I also purchased a set for my 560SEC and went into a bit more about the purchase there.


For the 250SE, I went with #53 Black/Grey.  This was an easy choice for the 250SE as it works well with the black interior and silver exterior.     Like the 560SEC, I went with the four piece set.    I have a centre cushion on my 250SE, so there is no console, but if there was a console there, I would have considered a console mat too.

There was a fair amount of adjustment required to the template for the 250SE.    This isn’t really that surprising given how few W111 Cabriolets were made in right hand drive, particularly the 250SE model with only 26.

UntitledAs you can see I had to be careful to go around the washer button and also the steering column.    The process of adjusting the templates is great.   It is time consuming, but it results in a set of cocomats that fit well.   Given I will probably be using these mats for a long time, it was certainly worth it.

At least if anyone else with a RHD W111 cabriolet wants a set, there is a good starting point with my template.     I don’t think my car was sold new with the Cocomats as it was picked up from the factory, but it was a common period accessory on these cars and I am really happy with them on my car.     I would recommend them for any classic Mercedes.

Cocomats for the 560SEC

A couple of months ago some of friends of suggested a group order for Cocomats. This coincided with a 15% off sale and shared shipping.   Cocomats are a floor mat made from coconut fibre and were a period accessory during the 1950s and 60s.    They were quite popular with Mercedes-Benz, Porsche and other manufacturers.    I have wanted to replace the generic rubber mats in the 250SE for a long time.    As well as the 250SE mats, I also purchased a set for the 560SEC.

I thought long and hard about which car would be best for the second set.   In the end I chose the 560SEC.   It still had the original dealer fitted mats.   Over thirty years later, the drivers mat in particular had gone all lumpy and discolored.

The cocomats are a huge change for the better.   They look great, fit really well and seem very high quality.   They are also really heavy so they don’t move around when you drive.


I went with #04 Blue/Natural. The Blue goes well with the Nautical Blue exterior and the Natural goes well with the cream interior.    I also considered the Natural and the Natural/White.   I am really glad I went with the Blue/Natural though.

cocomatsFor the 560SEC, I went with the four piece set.   I also considered the boot mat, but it is quite expensive for something that you don’t really see.   You can also get a small piece to go into the centre console.   It can look quite good but my console carpet is still in nice shape.


One of the things you really notice is what a good fit the mats are.   This is because they come from templates that are specific to the car.   Additionally, because the company don’t sell all that many RHD sets, they sent us the templates in paper form to check and make adjustments.

It take a couple of hours to get the templates right, but it is worth it once you see the result.   I found the best way was to use a sharpie to mark where I would cut paper from the template, and tape bits of paper on to extend.


Bad W126 window regulator

Another long standing to-do list item on my 300SE was the passengers side window.   Over time, the window would slip down so there was half a centimeter gap at the top.   It would also make a clunking sound at the top of the window travel.

I had purchased a good used W126 window regulator a couple of years back.   Yesterday I decided to try and fit the regulator.   To get to the W126 window regulator, the door card must be removed.     To do so, there a few screws holding it in place.    Two holding the little chrome embellisher near the door striker,  one behind the plastic backing for the door pull and three for the arm-rest.     Once the screws are out, the door card lifts up and out.   Many of these are damaged when people attempt to just pull it outwards.

Behind the door card is a moisture barrier.   Mine was in a sorry state.

W126 window regulator

I will replace this after I get the window regulator working properly. Next step was to check why the regulator wasn’t working properly. A quick test confirmed the behavior I had seen.

When I took a closer look at the mechanism, it was pretty clear why the motor was jumping like that.   The regulator was missing multiple teeth.

W126 window regulatorI wasn’t able to replace the regulator as the used unit I had was quite different to what was installed in the car.   Doing further research, it turns out it is for a coupe.    This isn’t so bad as having a coupe spare is quite useful as they are now hard to come by.

Looking at the parts catalog there are two regulator types possible for my car.   The first type was made by Brose and has part number 126 720 13 46.   I have this type on my car.   The second was made by Reitter & Schefenacker and has part number 126 720 17 46.   I understand the main difference is the number of teeth on the motor.   Therefore the difference doesn’t matter if you’re going to swap the regulator and motor as a unit.

While I was doing this job I noticed another wiring harness in the door.   It even had the little Mercedes-Benz pin connectors, so it was unlikely to be aftermarket.   Most aftermarket radios and alarms I have found in these cars were quite sloppily installed with the wires just twisted together.

I started a thread on the ozBenz forum and it turns out that it is likely from option code 551, which was the anti-theft system.   An unusual option for a low spec 300SE like this one.

Anti-theftI’ll leave the door card off while I source the new regulator.   It sure makes a difference to road noise though.

300SE cowl drains

Last year, while I was fitting the monovalve elimination kit to my 560SEC, I cleaned the drains under the cowl covers.    I also fitted a new upper seal and new shaft seals for the windscreen wipers.   The condition of those seals was even worse on the 300SE, so today I finally got around to doing the same job on that car.

I was especially keen to do this on my 300SE as water would get into the passengers foot well in the rain.   This would only happen when the car was parked nose up on an incline.   My theory was that debris may have been preventing this area from draining properly.

This job can be done in about two hours, even assuming a lot of cleaning time.   It is certainly worth doing on any W126.     As covered previously, the first step is to remove the wiper arms.   The little plastic covers flip up and the 13mm nut is behind.   The arms will only come off if they are raised.

300SE cowl drains

The drain covers are next. At least on right hand drive cars, the cover is in two pieces. There is a plastic fastener that holds the two pieces together that is just pulled out. The top seal is available for purchase, and these are often in poor shape after 20 years. The picture below shows the edge of the seal on my 300SE. The middle wasn’t quite as bad.

The lower seal is generally in much better shape as its covered by the bonnet. I was not able to find a replacement for this, but could re-use both of my seals. Once the seals are off, there are metal clips that hold the cowl drain covers to the firewall. Once those clips are removed, the drain covers can be gently lifted up. The metal clips hold it to the outer firewall and the covers have molded edges to clip in under the windscreen. I found an old toothbrush to be useful to clean the mesh part of the covers.

Unlike the 560SEC, which had debris from leaves in the cowl area, the 300SE had fairly thick dirt. No rust had started that I could see. The drain holes were open, but the thick dirt may have prevented the water getting to the drains in all circumstances. I’m hoping this cleaning of the 300SE cowl drains will stop water getting into the cabin and prevent rust.

300SE cowl drains

I’m not sure what it is fore, but there was a wiring harness that looked factory coming through the firewall into the cowl drain area.   Instead of being plugged into anything, it had just been taped up.   Please post in the comments section if you know what this is for.

300SE cowl drains

I was actually expecting more debris and some blockages here, so I guess it is possible that something like the windscreen seal is also leaking.   It’s certainly a lot cleaner than it was.

300SE cowl drains

Once cleaned, its quite easy to replace the covers and the two seals. I used my new upper seal and the new wiper shaft seals.

UntitledThis is the sort of job that is good to do at home as it would be expensive to get a mechanical to properly clean out this area.   Removing these covers really is very simple and the whole job takes about two hours, taking your time.   Having owned this car four years, I really should have done it sooner.

M117 fan controller prototype

A couple of months ago I tried a modification on my 560SEL to trigger the auxiliary cooling fan earlier.   The primary reason for this was to provide adequate air flow over the A/C condenser in stop/go traffic.   The W126 A/C was designed for R12 refrigerant and is marginal at best with R134A.    I used a resistor to trick the fan into running at a lower temperature.   It worked, but the temperature kick in was a bit higher than I wanted and the wiring was messy.    I thought a better solution would be to build a proper M117 fan controller.

The heart of the controller would be a potentiometer.    I had previously used a 1.1k ohm resistor which wasn’t quite enough.   A 0-2k potentiometer should give me all the range I needed to fine tune the cut in point.   My plan was then to build the potentiometer into a housing and leverage Mercedes-Benz connectors so it snaps right into the factory wiring harness.    That way, removing my M117 fan controller would be a simple matter of unplugging it.

M117 fan controller

The only downside of this plan for me is that it requires soldering. I hate soldering and use crimped connections where possible. The wiring above shows the rough layout of the controller. This then sites inside a metal hobby box with the plastic Mercedes connectors.

M117 fan controller

Once completed, I tried my M117 fan controller prototype in my 560SEC. I had checked the resistance with a multi-meter so I was surprised when I couldn’t get the fan to kick in even with the resistance at zero. Turns out the relay had died. Swapping the high speed relay with the low speed relay had the fan whirring into life.

Overall I am very happy with the M117 fan controller prototype. I have already identified two changes I would make to it. First one would be fitting the wiring to the housing before I soldered the Mercedes terminals so I only needed one hole at each end of the housing. Secondly would be to make the wires a bit longer to allow the box to fit into a better location. I have noticed that the knob is quite sensitive so minute adjustments are required. This isn’t really a problem as I will probably mark where the normal adjustment point I like is.

M117 fan controller

I’ll probably run the prototype for a few weeks and then build two more units as the permanent solution for both 560s.

S211 Tail light bulbs

My wife’s E350 Wagon recently started throwing up error messages about burned out tail light bulbs in the dash.   Turns out, this is not nearly as easy a fix as you would expect.   First, I consulted the owners manual.    The manual tells you that these bulbs are not user serviceable and do take the car to your Mercedes-Benz dealership.   I wasn’t really interested in a visit there, so I started trying to work out how to change the S211 tail light bulbs myself.

In the end I purchased a whole new rear light assembly from the USA.   From the USA it ended up being about $200.    They are pretty easy to swap over and I had the job done in a few minutes.   The side trim pops off and there are four 8mm nuts to remove.

S211 tail light bulbs

The old light assembly was clearly original to the car judging by the date sticker. Once I had it off I had a closer look at it to see if the old bulbs could have been changed. It doesn’t seem like the bulbs an be changed, but there is a sub assembly that they are attached to. On the EPC its listed as a ‘Lamp carrier’ so I assumed it was some kind of mounting bracket. In retrospect I could have just replaced this at 1/4 of the price and had a working light.

If I had taken more time when replacing the cracked tail light on the other side a year or so back, I would have saved that bulb carrier and had a repair for free this time. I have of course kept the old light assembly in case the current one is damaged. In that case I could use the old assembly with the new bulb carrier.

The photo below shows the carrier removed from the light assembly. It looks like the S211 tail light bulbs should be replaceable, but from all I can see they are not.

S211 tail light bulbsWhile I was at it, I also replaced the parking light at the front.   This was a simple bulb, same type as used in many of the older cars so I had one in my bulb drawer.

W126 Outside temperature LCD screen repair attempt 1

The W126 outside temperature display was standard in all Australian delivered series 2 models.   The little LCD screen is not really compatible with the Australian sun as most of them start to bleed and become unreadable.   My 300SE and 560SEC both have unreadable LCD screens.   The 560SEL, which was garaged all its life still has a good screen.

Buying a used one is not really a good option.   They are not particularly cheap, and even if a cheaper one from the USA can be sourced, it would be in Fahrenheit.   There is somebody in Europe who is selling replacement LCD panels so I thought I would give it a go.

Obviously to get to the LCD, the instrument cluster has to come out.   I find the easiest way is to remove the drivers side speaker and push it out from the back.   The W126 outside temperature display is screwed into the bottom of the cluster and can be removed without any other disassembly.

Replacing the LCD is as simple as taking the front off and then swapping the panels over.

W126 outside temperature displayThe little contacts on each side of the panel also need to come too.   When doing it, I couldn’t work out which side was the top.  I ended up guessing and I was wrong.   I guess I had 50/50 chance.

The backlight is also broken on my 300SE, so I dismantled the W126 outside temperature display to see if I could change it.   At first glance it looks like the little bulbs used in the dashboard.   However, its actually soldered to the circuit board.   My soldering skills are not up to this task so I don’t think I will replace it.

W126 outside temperature displayI got it back into the car and found two problems.   The first one is simple, I had the LCD upside down.   The second is more serious.   I didn’t read the description properly of the LCD, so didn’t specify I wanted Celsius.   The panel I have is for Fahrenheit which is useless to me.    So I guess that is about $65 down the drain, although I might be able to sell the panel.

I’ve now ordered two new panels to do the job properly and learn from my mistakes this time.

W126 outside temperature displayDespite my careless buying I feel good about this improvement.  The repair can be done without soldering, and seems to work quite well.   I should now have working temperature displays in these cars once the new LCD panels come in.

MBCNSW March 2021 Night Drive

Today was the monthly MBCNSW night drive.   Over the last week, Sydney has experienced the worst storms in sixty years.   The original route that we picked for the drive was not going to be possible.  It went down into the national park and close to flooded areas.   There was also the risk of unknown potholes in the road that we wouldn’t see at night.

Therefore, we decided to postpone the original route to June and do a much simpler drive this evening.   We met at McDonalds Thornleigh.   From there, we drove up Pennant Hills road and then down Pacific Highway to Woolloomooloo.   it was a good opportunity to go out for a drive and catch up with some of the MBCNSW members.

MBCNSW night drive

Given the weather, we had a great turnout of cars.   I took my 86 300SE.   There were three other W126 cars including a pristine yellow 280SE, a 380SEC which was sporting a new warm up regulator, installed just before the start of the drive and a very low mileage 420SEL.   We also had two very nice 450SLCs, a R230 SL, and some modern AMG performance cars including an E55 and a CLA45S.

MBCNSW night drive

After being affected by the rain for the last week it was good to get out for a drive. There was very little traffic on the road and Woolloomooloo was practically deserted.

MBCNSW night driveA few members came for the meet up point but didn’t go on the drive.   That is a good idea for those who want to come along but are not interested in such a late night.    Overall, despite the last minute change it was a very successful MBCNSW night drive.

March 2021 Rover P5 Coupe restoration update

Regular readers will remember I have been stopping by to check out the Rover P5 coupe restoration.   The updates show just how time consuming a proper restoration is.   Those TV shows that try to do one in a weekend really are quite silly.  There is a big difference in just slapping things together and doing the job properly.

To recap there are three Rover P5s under restoration.   A 1964 P5 Coupe MKIIA in manual/overdrive; a 1965 MKIIC in manual/overdrive (converted from auto) and a 1966 MKIII in manual/overdrive (also converted from auto).   The two MKII cars are both admiralty blue, but the 1964 car is two tone with a light blue roof.   All three cars are fitted with Webasto sunroofs.   There is a surprising amount of difference given the cars are all a model year apart.   The photo below shows the 1964 car.

1964 Rover P5 Coupe

There were quite a few jobs underway that will not be seen when the cars are finished but are still important.   The first was the front seat mechanism.   These needed to be dissasembled as they were not moving freely.   The control cables were not really designed to be disassembled so a lot of car was required to remove them and make sure the mechanisms were working properly.    The picture below shows the mechanisms for the MKIIC.

MKIICAnother component along the same lines were the door check straps.  Each one had to be disassembled, cleaned and lubricated.   Interestingly the front ones are slightly different to the rear ones.   Rover helpfully stamped a little picture of a front door or a rear door on the straps to identify them.

Check Straps

Another job like this is checking the alignment of the starting handle.   While the starting handle is not going to be used frequently (if at all), everything still needs to line up properly.   I did actually use the handle on my old P5 when the ignition switch stopped working.  It allowed me to start the car up at a Petrol station and continue on my way.

A particularly tedious job is aligning the bonnet on a P5.  This is why so many of them at car shows have misaligned bonnets.   It involves a lot of trial fitting to get it just right as there are two bolts that go into oval shaped holes to make sure the bonnet sits just right.

Bonnet alignmentFinally the 1964 car is starting to have the interior fitted.  The photo below shows the rear seat, upholstered in grey leather. It should look great with the navy blue carpet.   It can’t really be see in the picture, but the 1964 car will also get the drivers window regulator from my old car.  That regulator is in much better condition.

Rear seatIt will be great to see these cars lined up in the sun after they are completed.   What a good display it would be at a cars and coffee event.    It is rare to see a P5 coupe at an event like this, let alone three of them.

For more information on previous updates, please see:

450SLC wet feet

I’ve had a problem with wet feet in my 450SLC for years.   Generally this manifests itself with water dripping onto both the drivers and passengers feet when the A/C is running.   This is particularly prevalent when going around a corner.   I had always assumed that this was caused by blocked A/C drains.   I tried to clean them a couple of years back but the problem never went away.

A couple of weeks ago I took the car on an extended drive and had a lot of water covering my feet, but especially in the passengers side.   I figured it was time for another go at fixing this.

My first step was to remove the dash underside and see if the drains were still connected.   My previous attempt to clean the drains was from the underside of the car.    I was immediately presented with a rats nest of wiring and two old amplifiers.   The Becker amp even had the first owner’s name (Fletch).    The Becker radio is long gone, but the old amp was still there in the dashboard.   I guess Ian Fletcher (Fletch) had the amp repaired at some point.   This was a good opportunity to clean up all that old wiring.

Becker Amp

The drains did seem to be connected. The insulation for some of the pipes and valves had dropped down, but I don’t think that would be enough to create that much water.
As part of getting the side carpet back, I removed the carpet and insulation padding from the passengers side. It was soaking wet.

checking A/C drains

I use rubber floor mats in the 450SLC, so I hadn’t noticed how wet the carpets were on this side. Surprisingly, they were not wet on the drivers side. Unfortunately, the wet carpets have caused some surface rust on the floors of the car. I will have to grind this back and treat it.

checking A/C drains

As I hadn’t found anything obvious,  I decided to run the car for a while with the A/C on and see what happens.   This test was also somewhat inconclusive.    A ran the car for about 30-40 minutes with the A/C on.   I got no water in the car at all.   It also took at least 10 minutes to get condensate dripping out of the A/C drains.   The dripping was not as much as I expected and was only from the passengers side.   I put the car up on the hoist and tried to clear the drains with a metal rod covered with a plastic sheath.   I wasn’t able to free any water so not sure if I really did anything here.

My current theory is that the A/C drains drains are somewhat blocked.   This allows the evaporator case to fill with water.   As I drive around a corner, some drips on either the drivers or passengers side depending on the turn.   I don’t think this is enough to totally saturate the carpets, so I think I have a rainwater leak too.   I will need to do more work to isolate both and to treat the surface rust.