W140 Diesel - PeachParts Mercedes-Benz Forum

#1 10-03-2002, 05:50 PM

Hi
About a year ago I drove a 94 S350D.It had 320000 km and was running better than any diesel I tried.So much smoother than my 300sdl.
I hear these cars(or engines) have a bunch of problems so my questions are:1.Does anyone know for sure that the 95 model is OK?
2. If the engine was replaced on a 93 or 94 is it safe to buy one ?

What are the changes ?

As far as evaporator goes if it has been changed will it still be a problem or they have a better design ?

Thanks for the info
John
90 V8 q for now

gsxr · #2 10-03-2002, 06:04 PM

Hi John,

The W140 is an incredible car... almost too many gadgets, though. There weren't a "bunch" of problems, there was just one... the 3.5L OM603.97x engine used from 1990-91 (on the W126) and 1992-95 (W140). About half of the engines would "oval out" the cylinders and/or bend a rod. It usually happened with low miles (say, under 100kmi) but not always. One of the warning signs is increased oil consumption that keeps getting worse and worse. Usually by the time you notice it's too late. The fix is either a new bottom end or a new engine, which will run $6k-$12k plus labor. Anyway, to answer your questions,

1- The 1995 model is not OK. All the original 3.5L engines were flawed.

2- If the engine is replaced, it is safe to buy one from 1992-95 (or 1990-91 if you want a W126).

3- The changes... nobody knows for sure, because MB won't admit anything. But the new parts seem to be beefier rods, possibly different pistons, modified cylinder walls, or things along those lines.

4- Haven't a clue on the evaporator.

5- More info on the engine flaw is at this URL: http://www.mbz.org/info/complaints/350D/

Regards,

suginami · #3 10-03-2002, 06:22 PM

From reading the posts of owner's experiences on this site, I'd be inclined to believe that there was still a high failure rate of evaporators in 1995.

But, who knows? There are probably some that will never go out. There are those who have replaced it twice.

In any event, it is believed that MB fixed the problems with the leaky evaporators because the later ones didn't have the problem.

I've read they are about 25 shop hours of labor to replace one.

oldsouth · #4 10-04-2002, 04:53 PM

Well, I have almost 200,000 miles on my 1995 S-350 and it only uses a quart every 4,000-4,500 miles. Never touched the evaporator. From what I have read, about mid 1994 is when they updated the internal parts in the engine. Other than normal maintenance, the only thing I have done to mine is re-seal the turbo. I think the S-350 is a fine automobile and you can pick one up pretty cheap now days.

suginami · #5 10-04-2002, 04:56 PM

Yep, diesel or not, I looooove the W140 S-class cars.

I think that my next car will be an S500 coupe, after they've depreciated enough for me to afford one.

#6 10-05-2002, 02:03 AM

As I was browsing the net I found out that the 140 Diesel is alive and doing well in Europe.Most of you I am sure knew this.It must have carried over till 99.The prices are also excellent ,most with low miles because of shorter driving distances.
The 96 has bigger wheels,navigational system etc.
Would'nt be nice to bring one over ?
Probably not allowed I suspect.
Will wait 10 more years for the CDI I guess.(cannot buy it new)
John

lukemus53 · #7 10-11-2002, 09:03 PM

i have a '95 s350 with 117000 miles that uses no oil between changes at 4000 miles.it gets 24-26 mpg running the air.don't believe all you read on the web!

drbrandini · #8 10-11-2002, 09:17 PM

Quote:

Yep, diesel or not, I looooove the W140 S-class cars.

You can say that again, I test drove a 1993 S320 yesterday and man I fell in love. Lots of gadgets and comfort. The ride is also incredible subltle yet flowing lines. I found a little old ladie selling it with 88k miles, evaporator updated with the new part, silver/blue leather ........I gotta stop here my mouth is watering

Oh yeah aking price.....10,500

gsxr · #9 10-11-2002, 09:28 PM

Lukemus,

Uh, if you're insinuating that the reports of OM603.97x engine failing are either false or exaggerated, you are wrong. Not everything on the Internet is a load of crap (ok, there is a lot out there, but ths isn't it.) Just because YOUR engine is doing fine does not mean they ALL are and that they ALL are bulletproof. The general consensus from those who have more data than we do is that a bit less than half of them experience failure. It's just a warning that if you buy one, there is a POSSIBILITY it could fail. It's not guaranteed, not necessarily a ticking time bomb, just a possibility. But hey, anything is possible, right?

The difference between the 3.5L diesel and all other MB engines is this. The 3.5L has a much higher PROBABLITY of failure. It is highly unlikely that any other W140 engine will fail catastrophically. But with the 3.5L diesel it is moderately likely. How you like those odds depends on how much you love the W140, and the depth of your wallet.

drbarndini- yeah, I agree, the W140 is pretty sweet! And that price is stupidly low if the car is clean & cared for. And it has a REALLY nice engine... that's the 24-valve M104, isn't it? Mmmmm.... tempting...
:p :p :p

Regards,

oldsouth · #10 10-11-2002, 10:13 PM

Quote:

The difference between the 3.5L diesel and all other MB engines is this. The 3.5L has a much higher PROBABLITY of failure. It is highly unlikely that any other W140 engine will fail catastrophically. But with the 3.5L diesel it is moderately likely. How you like those odds depends on how much you love the W140, and the depth of your wallet.

I agree that there must have been something wrong with the 3.5 diesel or there would not be so much bad out there about it. I have faith in MB that when they see a problem they fix it. From what I have been told by MB, the internals were greatly improved in the latter years it was imported (late 94 and 95). In my opinion (other than the late model E class diesels; which are too small a car for my needs) the S-Class diesels are the finest diesels ever imported to the US. The 126 are good cars and the diesel engine is probably more reliable, but in terms of luxury-speed and acceleration-economy (I have never gotten under 24 mpg; up to 30 on a trip)-and overall features of the car, there is no comparison to the 140. My 2 cents.

drbrandini · #11 10-12-2002, 08:03 AM

Oldsouth,

I'm gonna need to see your license and registration please..

suginami · #12 10-12-2002, 01:12 PM

Man, that sure is impressive, isn't it?

29 degrees F and 120 mph!

#13 10-13-2002, 01:06 AM

Good or bad you all agree that W140 diesel is a very nice machine.Problem is I cannot have one.Government has decided that I can only drive Korean ,Japanese etc.
I cannot bring one from Europe but what I find more insulting is that I cannot bring one from US either(to Canada).Does Kia make a diesel ?
John

oldsouth · #14 10-13-2002, 01:13 AM

Quote:

Considering it's Louisiana, the 29 F is impressive by itself.

A pretty brisk morning. Seems to run better in the cool dense air. By the way, how do you know I am from Louisiana??

turnne1 · #15 10-15-2002, 09:53 PM

I am not sure of the failure rate of the 3.5...but there are many on the web who have said their cars have had problems(my personal car being one of them)...as for the Evap...my car is on its third...once in 1997 and once in 2001....according to the MB tech at the dealer that does most of the service on my car...the 140 evap core has been updated 4-5 times since the 140 came out in 1992...and yes that is a $2800-3200 job to fix

but with the 140(especially an early one) there are many probs....instrument cluster shorting out($1500)...power steering pump($1500)..closing assist pump ($750)...window motors...bose amplifiers...etc..etc....all not uncommon problems

good luck

Warren

1992 300SD 149K
Columbus Ohio