Tell me about 92-93 2.5 turbo diesels. - PeachParts Mercedes-Benz Forum

Ian White · #1 01-31-2010, 04:13 PM

I assume they are part of the elusive w124 body group. I don't know much about the w124 chassis or 2.5l diesel. I am looking at upgrading maybe. How are these cars? What do decent condition w124 diesel go for? I believe they use the OM 602 motor.

300GD · #2 01-31-2010, 06:04 PM

If you're asking about the '92-93 300D, yes, that is a 124 chassis and they used the OM602 engine. I have a 201 chassis car which used essentially the same drivetrain and I like the car.

bobodaclown · #3 01-31-2010, 06:12 PM

Hello. There's a few of us here. There good cars overall. Not sure about the 88 but 90-93 are turbo diesel. 90 and 91 are more alike and 92-93 grouped together. Between 91 and 92 they made some changes in the way the vac system works with the turbo and crossover valves.
They (90-93) all had the OM602 engine. (OM602.962) 5-cyl turbo. The turbo is controlled via the EDS system. EPA Fuel rating 26 city 31 highway. That's pretty close to what I get normally.
Couple things I've learned here about these engines. Overall very strong engines (durability) and reliable. Some bad points (rare but possibly a small trend). Blown head gasket (around #1 cyl), Change stretch (OM60X) engines, Turbo is controlled by EDS, which takes into account the EGR system. (If you bypass the EGR, disables Turbo). GSXR did a write up on conversion to a pressure (non EDS controlled) setup.

Ian White · #4 01-31-2010, 06:24 PM

Okay, I have been doing some research on these. I am asking for someone else who is going to be driving across Washington State in order to attend college. From what I have been reading the 603 in the 90-93 300's seem to better for crusing, which is the need. I have don a lot of work on my 617, so how much more difficult are the 603's? I am a competent mechanic. What does a nice 90-93 300D 2.5 turbo car go for, in acceptable condition? Maybe I'll need to upgrade from my 300SD to a w124 300SD. What do you think?

Thanks everyone!

bobodaclown · #5 01-31-2010, 07:33 PM

Hey Ian,
I'm a little confused. You asked about 92-92 300D. Those vehicles have the OM602, not the OM603. Not sure if thats a typo or not in your post. The OM603 was in the 87 300D and 300TD.

I believe the SD is the W126 platform

OM602 = 5 Cylinders
OM603 = 6 Cylinders (known as rod benders???)
OM606.910 = 6Cyl

Diesels in the W124 body style or E-class
Theres is no W124 300SD.
There is an 87 300D and 300TD (wagon?) , 90-93 300D, and 95 E300 Diesel.

http://en.wikipedia.org/wiki/Mercedes-Benz_OM603_engine
http://en.wikipedia.org/wiki/Mercedes-Benz_300D
http://en.wikipedia.org/wiki/W126

Ian White · #6 01-31-2010, 10:04 PM

Typo! I was wrong! How much does a good example with the 2.5L usually sell for? They seem rarer than hen's teeth in the PNW.

Jeremy5848 · #7 01-31-2010, 11:46 PM

The 2.5L engine is the OM602 with 5 cylinders, turbocharging, etc. Same as the 603 with one less cylinder. Mercedes fixed the head-cracking problem that they had in the 603 when they were developing the 602 so that is not a worry but the 602 still has an alloy head -- it will not take as much abuse as the cast-iron head in your current car. If a 60x engine loses its coolant, stop and figure out why. Do not "try to make it home."

The W124 chassis is the archetype for the low-Cd car that everyone copied. It is an excellent vehicle. Earlier versions are less complicated, later versions have nicer trim & more goodies. I recommend choosing from the entire range (1990-1993, right?) based on service records and a professional pre-purchase inspection rather than going after one specific year for some emotional reason. (I've never done that, of course.

)

A W124 with an OM602 engine was badged "300D 2.5" on the left side of the trunk and "Turbo" on the right side of the trunk. (Experts, please confirm.) Performance is good and fuel economy excellent, with posters routinely reporting probably real-world 30+ miles per gallon. No reason why you can't drive one cross-country.

Jeremy

Ian White · #8 02-01-2010, 12:09 AM

Excellent write up, thank you.

2.5-10 · #9 02-01-2010, 01:00 AM

190D 2.5Turbo FTW.

shertex · #10 02-01-2010, 08:36 AM

Quote:

Originally Posted by Ian White

Typo! I was wrong! How much does a good example with the 2.5L usually sell for? They seem rarer than hen's teeth in the PNW.

I have two of them and think the world of them. The more recent acquistion of the two, the 91, I purchased from a private seller for $4500 in April 2009. Excellent condition, low mileage (77,000 miles at purchase). But I think I got an unusually good deal.

shertex · #11 02-01-2010, 09:17 AM

Quote:

Originally Posted by bobodaclown

Between 91 and 92 they made some changes in the way the vac system works with the turbo and crossover valves.

I am intrigued by this comment as I own one of each. Are you able to elaborate, describe in any great detail?

Thanks.

Ether · #12 02-01-2010, 10:39 AM

Quote:

Originally Posted by Jeremy5848

If a 60x engine loses its coolant, stop and figure out why. Do not "try to make it home."

X2

Had a 90 300D a few years ago and I loved it. My son was driving it one day and less than a mile from the house the serpetine belt broke. Instead of pulling over, he drove it on home......Well, that was all it took for the head to warp. Oil in the coolant and so on.

It was till driveable though and good fortune shined on me as a few weeks later he banged it into a mail box and some trees (he was not hurt) and the car was totaled. I got a check from the insurance company for $250 less than I paid for the car 3 years earlier.

babymog · #13 02-01-2010, 11:38 AM

A few corrections:

The 603 was not known as a "rod bender", that's the 3.5L version in the '90-up SD/SDL.

The cracking head problem was not fixed when developing the 602, the early 602 also suffers and the head was updated at the same time, for the same reasons. This affects (in the US) only the 190D 2.5 & turbo, not the 300D 2.5turbo.

Badging was 300D on the left, 2.5 turbo on the right of the trunk lid. in '90-'93 for the 2.5L 5-cylinder, 300D on the left and Turbo on the right for the '87 300D with the 3.0L 6-cylinder.

For me, the 603 is best (MY '87) because of its power. For lower operating cost, I'd say that the '90/'91 300D 2.5 turbo would be excellent. Better fuel mileage, no weak head issues, and pressure-actuated wastegate.

Better/cheaper still would be to find a 190D 2.5 with a 5-speed, or a 190D 2.5 turbo, either can return close to 40mpg as mine did. Look for rocker-panel rust on these and a replaced head.

On any 60x powered car, the vacuum pump is another issue, if original it should probably be replaced.

2.5Turbo · #14 02-01-2010, 02:31 PM

Quote:

Originally Posted by babymog

For lower operating cost, I'd say that the '90/'91 300D 2.5 turbo would be excellent. Better fuel mileage, no weak head issues, and pressure-actuated wastegate.

The 90-91 cars have a vacuum wastegate just like the 92-93 cars. There were some changes in the EGR, intake flapper and ALDA plumbing for 92, but the operation of the system remained largely the same.

babymog · #15 02-01-2010, 04:36 PM

Hmm, my mistake. I'd still side with the '90-'93 then. The '95 E 300 Diesel is another good choice for fuel mileage.