91 300D 2.5 turbo/ is it worth looking at? - PeachParts Mercedes-Benz Forum

NC240D76 · #1 01-20-2004, 09:46 PM

I am looking at a 1991 300d 2.5 turbo with 130000 miles that does not seem to have any rust or mechcanical problems and is in very good shape inside and out.
Any problems specific to these cars I should look for or avoid?

Thanks for the help

#2 01-20-2004, 10:03 PM

I have heard the EGR is hard to disable without the electronics freaking out.

Other than that, I have not heard of anythng else.

NC240D76 · #3 01-21-2004, 07:26 AM

Any special reason to disable the egr?

I know this car will be more complicated than my 240d but can I work on it or is it all computerized dealer (expensive) type maintanance and repair.
Thanks

Rick Miley · #4 01-21-2004, 11:50 AM

The 2.5 is a fantastic engine, so nothing special to look out for there. You'll want to be more concerned with W124 chassis issues like A/C evaporator and rear suspension. I'm pretty sure that car should have an R12 system, and could be a disaster if converted to R134a.

NC240D76 · #5 01-21-2004, 02:09 PM

This is the second or third type I have seen a thread saying not to use the R134 in a mercedes diesel but I have had my 76 240d converted over for three years without problems and it seems to get colder than with the R12 (it was leaking with the R12 and I converted when I had the system fixed).
Is it just certain systems or am I going to have trouble with mine in the future?

I have not dhecked the evaporator or rear suspension just the things I knew about for the 115 and 123 bodies. Thanks

Cressida · #6 01-22-2004, 10:33 AM

Quote:

Originally posted by NC240D76
This is the second or third type I have seen a thread saying not to use the R134 in a mercedes diesel but I have had my 76 240d converted over for three years without problems... Is it just certain systems or am I going to have trouble with mine in the future?
D

A lot will depend on the quality of the conversion. I agree with the others. If the car was originally R-12, KEEP IT R-12. If there are leaks fix them. For any MB that was originally R-12 and now is R-134a, I'd reduce the price accordingly and expect problems down the road. I will never use R-134a in any of my vehicles that were originally R-12.

CSX293 · #7 01-22-2004, 11:47 PM

Hi guys - I've been a lurker for quite a while and thought I'd finally chime in on this thread:

I have a 91 300D and have found it to be a very robust car. It had 160K when I bought it and I have run it up to 181K over the last 6 months... and it was no pampered pup when I got it. Don't get me wrong, she cleaned up well but the PO wasn't exactly on the ball with maintenance. I guess I can't blame her with what the dealerships will charge for maintenance - and not to mention that's why folks like us pick up these cars at a reasonable price. (Notice I didn't say guys, as there are a few women on the board too!)

When I got it needed the following right away:
Injectors, Injector pump seals, rear brakes, tie rod ends, blower motor brushes, 1 glow plug (very easy to figure out which one).

On the list of things to do are: flex disk, and maybe turbo seals (time will tell on this one).

I changed it over to synthetic oil on the first change and have had great luck. 30 - 33 MPG on the highway and the thing just goes and goes.

If you want to chat off board about the car, feel free to contact me.

#8 01-22-2004, 11:57 PM

Quote:

Originally posted by CSX293
Hi guys - I've been a lurker for quite a while and thought I'd finally chime in on this thread:...

...(Notice I didn't say guys, as there are a few women on the board too!)

CSX293 · #9 01-23-2004, 12:02 AM

Just checking to see if your paying attention!

CSX293 · #10 01-23-2004, 12:24 AM

Can't you just block the EGR with a plate on this model?

NickMendoza · #11 01-23-2004, 04:08 AM

I will recommend this car to anyone who is willing to work on cars and have time to read this forum.

Why=Anything over ten years old will require some amount of maintenance work.

These cars do hold up better that most other cars the same age. Maybe it is because people tend to take care of them.

Watch out! If the car has not been taken care off. OIL Changes every 3000 miles run away. Some have extended the oil changes using synthetic.

Areas to look at:
Differenstial mounts (people jack them up from Differential)
Control arm bushings (rear and front)
Flex discs (Two)
Bearing (In the middle of driveshaft)
Motor mounts (does it shake a lot)
Tie rod ends or tie rod assemblies (allignment)
AC=take it to a tech and have them do a pressure check.
Mine had R12, R134 and propane. Just finshed that one.
Use R-12 in a car designed for R-12! Said the tech!

I tried to block the EGR (off road only) . It effected the performance. I am doing research on this one.

Take it to a mechanic and spend about $75.00 for a pre-purchase inspection.

Have him check compression , exhaust system and fuel system.

I love my car. My girlfriend gets mad when I stay about 5-10 extra minutes at the fuel station. The truckers always ask about the car.
Gas in CA. is 1.95 super, 1. 75 regular and 1.60 for deisel.
The car gets about 30MPG +or-

Luck

Nick Mendoza

NickMendoza · #12 01-23-2004, 04:11 AM

I will recommend this car to anyone who is willing to work on cars and have time to read this forum.

Why=Anything over ten years old will require some amount of maintenance work.

These cars do hold up better that most other cars the same age. Maybe it is because people tend to take care of them.

Watch out! If the car has not been taken care off. OIL Changes every 3000 miles run away. Some have extended the oil changes using synthetic.

Areas to look at:
Differenstial mounts (people jack them up from Differential)
Control arm bushings (rear and front)
Flex discs (Two)
Bearing (In the middle of driveshaft)
Motor mounts (does it shake a lot)
Tie rod ends or tie rod assemblies (allignment)
AC=take it to a tech and have them do a pressure check.
Mine had R12, R134 and propane. Just finshed that one.

I tried to block the EGR (off road only) . It effected the performance. I am doing research on this one.

Take it to a mechanic and spend about $75.00 for a pre-purchase inspection.

Have him check compression , exhaust system and fuel system.

I love my car. My girlfriend gets mad when I stay about 5-10 extra minutes at the fuel station. The truckers always ask about the car.
Gas in CA. is 1.95 super, 1. 75 regular and 1.60 for deisel.
The car gets about 30MPG +or-

Luck

Nick Mendoza

NC240D76 · #13 01-23-2004, 08:20 AM

Okay, this is the second mention of the EGR or blocking it. Can someone explain the reason?

Thanks for the help

cwa · #14 01-23-2004, 10:07 AM

I don't know why anyone has had problems with converting an older Benz to R134a.

Both my current '87 300TD and my previous '79 300D were converted to R134a. My mechanic did both and there were no problems with either. I put at lest another 80,000 miles on the '79 after this was done.

His recomendation is that you have to have a rotary type commpressor and not the older piston type. This was changed around 1980 or so. My '79 had an updatre to the rotary so it was possible to change it.

This conversion was done with a complete A/C system flush which is expensive ($50/gal + time). Then of course a leakdown test and a refill lwith R134a.

Just my veiw point on this one.

Rick Miley · #15 01-23-2004, 10:26 AM

NC240D76, the EGR and R143a have been discussed at length, so you can find that information by searching the archives. That's why I'm reluctant to go through it all again here. If you need help searching, let us know and somebody will help.

The short version of the answers is this: the EGR clogs up the intake manifold with soot, and Mercedes air conditioners are weak so they don't tolerate conversion well.

I put 3 compressors and a condenser in a black 300E in the span of 18 months and sold the car when the evaporator blew. Anyone who wants to follow in my footsteps, please go ahead and convert to R134a or, worse yet, buy a car that has already been converted so you don't know the quality of the conversion job!