Ok, I have the chance to get a 1991 420sel for a very good price. it is that price because it runs like crap. As I understand it, there was a transmission replacement and it hasn't run well since.

The description I have is that it just has no power. It will accelerate, but only VERY slowly. given time it will get up to highway speed and even climb long steep hills with only some loss of speed.

I realize this is quite vague, and I don't expect a dead on dx. I am new to mb, but have considerable xp with a wide variety of things mechanical. I also know that this car has been in the hands of 2 "mechanics" neither with any mb expertise.

So what I think the people on this forum can do, is point out the things likely to account for such performance with an eye toward stuff that would be missed by non mb people.

any thoughts or observations appreciated. I am posting because I have to travel 600 miles to get the car and if this is an "oh yeah they do this, and it's xyz" kind of problem, I'd like to know that before I go rather than wishing I had asked...

Thanks
David

That thing could be a real money pit nightmare.
How many miles are on the car?

Those cars are usually owned by m/b mechanics because they are tanks and great highway cruisers, but always need attention.

Most techs usually end up rebuilding the suspension, resealing the fuel pump package and hoses, replacing the timing chain and rails, rebuilding the transmissions and going over whatever engine, fuel, wiring, components problems, mechanical, electrical, exhaust just to get it road worthy.

Other people drive the living tar out of them, neglect the scheduled maintenance and only fix it when it strands them, l just casuse they feel important driving a Benz.

A good deal may really be a bank account nightmare for you if you decide to fix everything that it needs to run right.

so this is not a particularly reliable or durable model?

I'll post a new thread once I have the car and can fill in details.

I don't think you will find that most folks agree with cuda's thoughts.

The 91 will be the 126 body car. It is generally thought that the 126 cars are very very well built and very reliable when brought up to snuff. The engines are durable and reliable too, but major repairs can be expensive if needed.

The fact that this car has been worked on and diagnosed by amatures just makes the possibility that it is something repairable better.

The fact that it will eventually climb hills at highway speeds makes it seem likely that the problem is not major. I would look first at the throttle linkage to see if it is getting full travel. And if that is good I would look at the fuel supply for restrictions such as a pinched line or plugged filter. And I would look in the tank for debris or foreigh materials.

Good luck.

Tom W

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

THanks Tom, the additional perspective helps. I thought surely a running 420 with a sound body/interior would be worth troubleshooting a poorly running engine.

David