Faults:

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.)

Faults:

There is a noise from the rear suspension when a wheel hits a sharp bump in the road.

The dash had a couple of cracks extending from where the speaker covers are situated.

It uses a bit of oil.

General Comments:

I love this car. I have looked at buying a W126 or W123 for about the past 10 years, and finally found myself an example that is in fabulous condition.

The service history is perfect, and I have carried on the getting serviced at my local dealership. While the labour isn't cheap, I know the car is worth the extra cost.

This car is lovely on the open road. It's so quiet for a 21 year old car, and doesn't use too much fuel. Once up to speed, the performance is more than acceptable.

I get plenty of positive comments about the car. I can see myself still driving this car in 20 years. I got the dash cracks fixed before I purchased the car, and have fitted an after market stereo head unit. I love it.

Faults:

Radiator (plastic parts), battery (not a big deal), blower fan regulator/master brake cylinder (cheap to fix!). Upgraded to Zimmerman's drilled rotors (much better stopping!), new ATE brake calipers (front).. tie rods & center drag link & steering dampener (not a big cost to fix). Do not go to a DEALER, I put spark plugs in myself!

If you are a competent car person, you can save thousands, & I KNOW the work got done!

General Comments:

I've had ALL kinds of cars... Mercedes is a "SOLID" investment; you fix it and it stays fixed..

Faults:

EGR line was clogged with carbon.

Power steering reservoir leak.

Muffler.

Brakes.

Key tumbler.

Power door locks and antenna.

Passenger door has to be slammed shut. Can't fix or it will ruin the seal around the door. I just get used to it.

Terrible on ice and snow (similar to a Chevy Camaro as far as snow handling). Rear tires spin even on wet pavement when starting up steep hill. This was similar to my rear wheel Volvo as far as snow handling.

General Comments:

This is the most luxurious car imaginable. Still looks new inside, and everything works.

For the mileage, it is very reliable. I have owned the car from 167,000 to 202,000.

New parts are very expensive. Don't buy if you cannot afford $3000 in parts at some point. Power steering kit was $2600.

Much less expensive overall than a newer car. I paid $6200.

Must be maintained. Service only at a Mercedes dealer or German-born mechanic (others charge more money than Mercedes dealer, and don't know what to look for or have bad attitudes).

Exceptionally roomy interior.

Very rugged, built like a Russian army tank, you can't hurt it.

In a class of its own, much more impressive than a Cadillac.

There is no reason to buy newer, and newer is certainly not an upgrade. This one was built to last and better than newer models. No electronics problems.

Mileage impressive for weight: 23 mpg on highway at 85 mph, 11 mpg in City on very short trips in winter only. 16-19 mpg in summer mixed driving.

Drives over 110 mph with little vibration.

Exceptionally heavy car, not for tailgating. Keep following distance.

Exceptionally long wheel base has pluses and minuses. Not for quick lane changes on crowded freeway or tight parking spots. Not good for fast speeds on uneven dippy pavement where a small car might be O.K., but excels on rough roads. Leans around corners more than a small car. Ride is as smooth as gliding on air, while at same time delivering a real feel for the road (a remarkable combination of luxury and sport feel).