250SE W111 Production Figures – Update

In a previous post, I was looking at the changeover of production of the 220SEb Coupe/Cabriolet to the 250SE Coupe/Cabriolet.   Mercedes used the same number series for the 220SE Sedan, 220SE Coupe, Cabriolet and the 250SE Coupe and Cabriolet.

According to a Mercedes Factory Manual I have, the last 220SEb was #82991 (and the first 250SE #82992).     At the start of 250SE production in 8/65, the Coupes and Cabriolets received a slightly different engine to the Sedans (M129.981, M129 II),  whereas as of #85398 in 4/66, the M129.980 (M129 I) engine from the sedan was standardized on both models and the 981 engine was discontinued.    The 250SL continued to receive M129.982 (M129 III).   Looking at the parts book, M129.982 is has a number of differences from 980/981, whereas the difference between 980 and 981 appears to be very small.

We know that Mercedes produced the following number of cars (coupe and cabriolet combined):

  • 1965 – 1205
  • 1966 – 3601
  • 1967 – 1407
  • Total – 6123 (954 Cabriolet, 5259 Coupe)

Pre-Production was 8/65, standard production 9/65 and end of production was 12/67.   It is interesting how production tapered off in 1967 given it was almost a full production year.  Looking at dates to serial numbers (obtained from data cards for ac curacy), we can see:

  • 8/65 – 82992 (1st car)
  • 10/65 – 83113
  • 2/66 – 84462
  • 4/66 – 85398 (Engine type change)
  • 6/67 – 88627
  • 10/67 - 88864

Final DS door card installed

The fourth and final door card for the DS is now installed.   The reason for the long delay was that the rear drivers side door would not lock.  If the door was unlocked, the mechanism would not hold the door closed, if locked, it would behave as if it were unlocked.

Therefore, before I fitted the door card, I wanted to fix the door.   The mechanism is actually quite simple, just hard to see and get to.

Door Handle and lock MechanismEssentially what happens is that the rod (12) gets somehow misaligned, which stops the little star in mechanism (2) to hold the door, and the little cam to lock it.    After various attempts to try and adjust it, something worked, as it started to work properly.  Access is not easy, as can be seen through a mirror.

AccessOnce the lock was sorted out, the door cards are easy to install – in the same way as has been outlined already.  As usual, a little autosol on the winder mechanism completes the job.


Flashback: Sunday, April 20, 1972. Mercedes M110 Engine Launch

EMBARGO: Please do not publish before Sunday April 30, 1972


Confounding the criticism that today’s automobile engineers are too heavily engaged in meeting safety and pollution requirements to produce better vehicles, Mercedes-Benz has just unveiled a superb new twin overhead camshaft engine.

As well as meeting the conflicting requirements of performance with economy, the new engine also makes a positive contribution towards active safety by producing plenty of “overtaking power.” A s befits an engine produced to meet the needs of the 1970′s, it is also as “clean” as possible.

Technically sophisticated, the engine also demonstrates that the development potential of the conventional reciprocating piston engine is still a long way from reaching the end of the road. Always provided, of course, that the people doing the developing have the requisite “know-how:”

Equipped with electronically controlled fuel injection and transistorised ignition, the engine develops 185 DIN hp, which is 210 SAE bhp or 136 kW – the new international rating now called for by a recent EEC ruling.

The cylinder head has hemispherical combustion chambers to ensure optimal combustion of the fuel mixture. The valves are arranged in V-formation, and are operated by rocker arms directly from the two overhead camshafts. This is an expensive method, usually found only on engines built for sports cars, but it produces a free-revving engine
capable of up to 6,500 rpm. Such liveliness is made possible only because the weight reciprocating back and forth in the valve gear has been kept to a minimum.

The two camshafts are driven by a duplex roller chain. An intermediate gear drives the distributor and oil pump. Both inlet and exhaust valves are armoured and the exhaust valves are sodium-filled for cooling purposes.

The engine has a distinctive appearance with its two smart looking overhead camshaft covers contributing to under bonnet “eye appeal.”

m110Both camshafts may be removed for repairs without having to dismantle the cylinder head, so that the engine’s cooling system need not be disturbed and repair times are kept to a minimum.

At the “bottom end” the crankshaft rests in seven main bearings and there are no fewer than twelve counter weights on the crank webs. Anew type of double weight vibration damper has been introduced to further damp down oscillations. This results in an unusually smooth flow of power.

A special oil injector is incorporated in the connecting rod to assist with the cooling of the piston crown. A great deal of research went into the development of the shape of the combustion chamber. This ensured that the engine would burn its fuel fully and cleanly, thus releasing the maximum amount of power for the minimum toxic exhaust emission. An oil cooler, visco-drive fan and three-phase generator complete the picture of this, the most modern Mercedes-Benz engine.

Electronically controlled fuel injection was pioneered in Britain by Mercedes-Benz with their 250 CE Coupe model, first introduced here in May 1969. This was truly the dawn of motoring’s “electronic age” and the adoption of electronic fuel injection by other marques since has been rapid and widespread.

With this system an electronic calculating device virtually a miniature “computer” works out precisely how much fuel the engine needs. It does this at speeds of up to nine thousandths of a second (a micro¬second in which most full-size computers work is one ten-thousandth of a second). Before deciding how much fuel the engine needs, the “computer” gathers information from sensors about the number of revolutions per minute the engine is doing, the position of the accelerator, prevailing air pressure and the temperature of the engine as well as a number of other factors.

Fuel is held under pressure in lines leading to electro-magnetic valves in the cylinder head’s inlet ports. Electronic impulses from the calculating device allow these valves to open for fractions of a second to enable the fuel to spray into the combustion chamber. At idling speed the valve opens for two-thousandths of a second, and at full power nine-thousandths of a second.

Transistorised ignition is also fitted. The main benefit of this system is that it places only a relatively low loading on the contact breakers, reducing burning of the points. This ensures that once correctly set, the timing stays adjusted for long periods – a most important point in achieving good power output, fuel consumption and “clean” exhaust values. Timing adjustment is made extremely easy and precise by a new setting device on the engine designed to be used in conjunction with an electronic workshop instrument.

This new engine, installed in the robust and technically advanced “New Generation” body/chassis unit, with its diagonal swing axle and powerful disc brakes all round, will extend the Mercedes-Benz range in a new and positive direction.


Sunday, April 30, 1972

280CE, Runing, registered and sold!

The 280CE is finished.   New muffler, passed blue slip and sold.   My brother has purchased the car as he wrote off the BMW that we ‘dismantled’ earlier.    That means that it will still be featured on this website from time to time even though I no longer own it.

CEThere are still a few things needed to do on the car, but otherwise it is good to see it on the road again.  Those with eagle eyes will notice that the muffler has one pipe, rather than two as is correct for the 280CE.   Even an aftermarket muffler for the 280CE was $500-$600, so in the end we purchased a standard muffler of a wider pipe diameter and had the pipes joined together.

280CE no longer a colander

Skin grafts?

Not a perfect match, but a good repair for $300 cash.

280CE Tie rod replacement

The 280CE was making a knocking sound while steering and it had failed its rego due to a bad tie rod, necessitating a replacement.   The job is not that difficult, especially if you have the right tools.   There are a few good resources on the Internet, but a few things I found:

  1. I couldn’t remove the ball joints with a pickle fork, but it was straightforward with the specialty tool.
  2. Raising the car off its wheels put more stress on the joints making the job harder, ramps were easier
  3. The joints will break free suddenly, so be careful

20140812_124343Web resources:

Small rust hole causes the CE to fail its blue slip

After replacing the water pump and test driving the 280CE, it was time to get it registered.

Unfortunately it failed due to a small rust hole in the body work.   This is not structural, but NSW is very strict in this regard.     There was also a minor leak from the power steering and minor leak from the rear muffler.   All will need to be addressed.

CE Rust

W123 Mercedes rust here when leaves and other debris are left to sit around the bonnet hinges – they break up and fall through and you end up with wet mud that lets this rust from the inside out.

280 Rust

A repair like this should cost a few hundred dollars to put right if you’re not looking for a showroom job.

The 280CE runs again

The 280CE finally has a new water pump and no longer leaves an embarrassing puddle where it sleeps.

After fighting with the bolts on the visco fan, it was finally able to be removed with a combination of drilling and vice grips.    After that, the rest of the disassembly was not nearly as bad.   In total, to get to the water pump on the M110 engine you need to:

Stuff removed

  1. Remove radiator – remove top and bottom hoses, transmission oil cooler hoses and securing clips
  2. Remove fan shroud – Clipped to radiator
  3. Remove fan from viscous fan assembly – four bolts behind the fan
  4. Remove viscous fan from the water pump pulley.   Four easily rounded bolts which took the longest.  I replaced these.
  5. Remove drive belts (these were ultimately replaced)
  6. Remove water pump pulley – this just comes off once the fan is unscrewed and the belt removed.
  7. Remove crank pulley and large balancer – secured with allen bolts which are easier to get to with an allen socket.
  8. Unbolt water pump – five screws, these were a bit rusty so I replaced these
  9. Remove water pump – I had to hit with a hammer to free it.

The leak was coming from the water pump as suspected – the water pump was in poor condition, and had been fitted without a gasket.   The first pump I purchased was the wrong one, so a replacement was purchased from MBSpares which fit (mine was a model for cars without a visco fan).

New water pumpThe Mercedes manual called for 9NM for the water pump bolts, but this seemed very loose, so we tightened them up until snug.   Installation was pretty much the reverse of the removal, and while we were at it we installed new belts, new radiator drain plug and a few other things.

FinishedThe 280CE then got two new tires to go for its blue slip tomorrow to try and get registration.

280CE sticking ignition key

The 280CE had a sticking ignition key.  This can turn into a real problem as the way to change the tumbler requires you to be able to move it, so if you cannot, then you end up having to take drastic measures to remove it.   It is much better to replace it while it can still move.

You have two options to replace – you can buy a tumbler from Mercedes that has the same keys as the doors and the original tumbler.   This an be ordered from the dealer with the data card.  Or you can get a generic one that is much cheaper and have a different key for the doors and ignition.   It also means if you loose your keys you can’t order new ones from the dealer.   Despite these drawbacks, I went with the generic option for the 280CE as it was much cheaper.

This repair is easy and there are a few videos on the Internet on how to do it.    The key is inserted and turned to the ACC position.   A thin metal rod (e.g. straightened paper clip) is then pushed into the little hole which if pushed hard enough allows you to unscrew the black surround and remove the tumbler.


As well as this, A few bulbs needed replacing.   A tip here is to refer to the manual as to what bulb is required, and disregard what was installed previously.

2014 French Car Day

Today was the annual French car display day.   Like last year, the event is put on by the French car clubs in Sydney, i.e. Peugeot, Renault, Simca etc.   It was a lovely day and a good turnout – especially of DS including a few cars I had not yet seen in the club.  A couple of cars in particular:

- A yellow D Special that was for sale not long after my car and was purchased by a club member and subject to a well documented restoration on Aussiefrogs.

- A red Safari that was purchased in bits a few months ago by a club member and is already assembled and running.

- Jason’s DS (Jason looks after my car), which I had heard about, but not ever seen.

- A DS Pallas in a beautiful gunmetal colour.   Not sure who owns this car, but it looked great.   These dark metallic colours look great in Pallas spec.

- Many old favorites I have seen before.

I took some photos of the older cars at the show, and a video of the older Citroens.  One difference I noticed from last year was that there were less of the niche French marques.