1989 Mercedes-Benz S-Class 420 SEL 4.2 V8


The car that started it all off


Ignition module died (expensive (r) fix).

Fuel pump relay needed replacing.

R/F window motor had given up the ghost.

That's pretty much the major faults.

Lots of DIY maintenance by me and some by independent MB specialists.

Timing chain guides and tensioner @ 406000 km.

Need to change the chain itself (which is available with me).

R/F window motor and regulator replaced, but it's noisy and unrefined.

Air filter @ 390000.

Ignition leads, rotor, cap @ 392000.

Engine mounts @ 393000.

Fuel filter @ 393000.

Oil changes every 3000 - 6000 km.

Transmission filter and filter @ 395000.

Fuel pumps are noisy.

A/C not working.

Valve-train noise.

Fuel distributor dumping in excess fuel me thinks, therefore 20L/ 100km fuel economy (and/or the high mileage issue which may be causing this).

Slight lumpy idle in gear when the engine is warm.

Suspension and steering needs a bit of attention.

Wheel bearings look and sound OK, but need to change for a peace of mind.

Brakes are starting to squeal slightly.

1st gear sounds like a straight cut (transmission needs replacing), but car starts off in 2nd gear anyway, so not much of a problem.

R/R window regulator has a damaged plastic sliding jaw.

Paint is starting to show its age.

There are a lot more problems.

General Comments:

I have brought this car from my dad for $4g two years ago.

My main daily driver, which I have maintained to the best as I could possibly have done with my limited (or none at all) earnings (I'm a Uni student).

When my dad had this car, the ignition module went, so $2000 later (module, coil, various useless parts and diagnosis :P), this took 9 months to find a replacement module.

My dad had enough of this car, that's where I stepped in.

This car changed my life (and shrunk my wallet just as fast); the car noob that I was before is no more, and I have gained knowledge in the automotive field, and am currently studying to be a auto engineer.

So far I spent around $2700 in the two years I had this car in parts (not including the oil changes/ filters).

Older Mercedes are relatively simple to work on (if not time consuming) yourself, and with the info that is on the net, more affordable than sending to the dealers on a regular basis. I have calculated for the work I have done myself, I have saved over $5000 in the two years of ownership for the work done.

But there are some jobs that I cannot do myself, and had to send it to a Mercedes specialist, which was actually a bit expensive, but I did not mind as it was only a few jobs (engine mounts, and fuel filter while the mounts are being changed).

I don't plan on selling this car, will just get the car back to good condition as it should be; it seems like a lost cause, as the car has done more than 400000 kms, at which point most people would just scrap the car.

But I'm not "most people".

Maybe later AMG kit, AMG 3 piece rims, Recaros, m119 engine (or m120, or a 5.5 AMG V8) and other goodies, but that's just a dream for now.

I would gladly buy another W126 (if I had the money) and another non W126 along with it, as long as it's a SEC and/or a 190. But I will not sell this car.

Would you buy another car from this manufacturer? Yes

Review Date: 20th March, 2011

22nd Sep 2012, 22:32

The SEC's are still W126 bodies.

10th Oct 2012, 11:19

By definition.

Or C126 to be exact.

1989 Mercedes-Benz S-Class 560 SEL 5.6L petrol


Very, very impressive for a car of its age - but never again!


Failure of silly self-leveling hydraulic rear shocks.

Failure of hydraulic pump for silly, over-engineered, self-leveling rear nonsenses.

Started burning oil (appears to be valve stem seals).

Fuel pumps failed.

Electrical failures... window winders, aircon, windscreen washers locked on, stereo speakers randomly drop out... basically anything electric is dodgy.

Rear wheel bearings... a nightmare to repair.

Water pump. What a sod to get out (one bolt had to be hack sawed off).

General Comments:

Despite the failures noted above, I love this car. It's powerful and heavy, so it makes a great towing car for my boat. It looks well, it has loads of space, it goes like blazes.

It's deceptive: the throttle pedal travel is very long, so you tend not to use much throttle, but if you push it all the way to the floor and kick down below about 100 kph, it is very very respectable, and below 50 kph, where it will kick into first - it will knock your eyebrows off. The ride is a bit less than you'd expect: OK, but much more road roughness comes through than you would expect. I have a similarly-aged Jag XJ, and while it is much less powerful, it rides much more smoothly (while still being much more taut in the corners).

Fuel economy is not bad considering the engine size. I get 18 mpg on average, more on the open road.

The reality is that it's wonderful to own, but I'd never touch another Merc with a 10 foot pole. There is a distinct air of over-engineered frippery that goes wrong. And I've noticed a lot of other older Mercs burn oil too. Not something you'd expect at the mileage I've got on the clock (not much over 100k miles when I bought it.)

Would you buy another car from this manufacturer? No

Review Date: 26th December, 2010

22nd Aug 2015, 20:49

Any owner experiencing exhaust smoke should carefully examine it for color. If it is grayish, remove the vacuum hose from the trans. modulator valve. If the smoking stops, replace the valve. Easy fix!