Hi I bought a very clean 91 350 sdl that was reccomended to me by my mercedes mechanic two months ago. It has run very well until two weeks ago. When I start it it runs rough and blows clouds of light colored smoke until warm. I thought it could be the fuel and replaced it with fresh fuel and added a diesel fuel additive and the smoke has subsided.It still runs a little rough when cold but once it is warm it runs great. I took it to my mechanic and he did not see any mechanical problem.The car had new injectors and glow plugs installed last fall. Any Ideas?

Chris,

You did not indicate how many miles are on the vehicle. Irrespective of that, I'm afraid you may have potentially gotten yourself into quite a fix with the 350. The '90-'95 350 SD/SDL/S350 has the OM603.97 engine which as a history of premature failure. Rather than articulating the details here, I recommend you visit this link to learn more about the reasons behing the problem, as well as symptoms.

http://www.mbz.org/complaints/350D/

Did the mechanic that recommended it work for MB? Regardless, I would engage him/her immediately and make an effort to hold him/her accountable. Any decent MB mechanic should know of the history of this engine. Sorry for the news. :(

Hi the car has 119000 miles and burns no oil no leaks or anti freeze loss. it appears to be sound up until this rough idle when cold.

Check your glow plugs. Mine runs rough until you take off and get the rpms up. Only smokes if I haven't added any red line to the fuel for a while.

If it's less than 40 F I aslo plug in the block heater for at least an hour before starting.

Thanks that sounds similar to mine. I am a little scared about the engine after reading about it but mine really is nice and has been very well cared for. I am hopping that it will last and run as well as my 85 300d did.

Before you panic and spend money run a couple of tanks of diesel with a good dose of conditioner first. A bad tank of diesel can really mess up an engine. It takes several refills to purge the crap from the tank. Keep close track of oil and coolant.

I bought mine with 106k on it. You may also want to change every fluid there is, brakes, rear end trans, etc. I did just to know what was in it.

Email any news of your 350. There are several owners here in the shop but only non owners blat the bad press from mbz.org. Have yet to hear someone who takes care of their car tell the story.

I just had the same problem with my 300D. It turns out the car had a bad glow-plug.

350 sdl
 

I would like to hear from some owners who have had experience with this car. I bought one two months ago and it has been great. All but my little problem with some poor quality fuel. This car is so clean and the engine runs so well I have trouble thinking that soon the engine will fail from the no. one cylinder wearing.and eventually bending rods

Well guys I have one of these vehicles that has had engine probs....total new engine at 103K(warranty).
I bought the car at 90K and the car appeared to be very clean and taken care of...but none the less at about 98K it started smoking and by 102K I was burning a quart of oil every 180 miles
So now I have a new engine with a MB 48/50 parts and labor warranty
The MB regional MB rep said that some people never had problems with this engine so it could very well be a maintenace issue..but in any case there must have been several modification done in late 1994 early 1995 to alleviate this "problem" as I have seen no newer cars with this problem and there seem to be no repeats of this problem with the people that had new engines installed..I guess MB found the weakness and corrected it
In any case I think MB will offer goodwill on this engine if it has less than 75K and a documented MB dealer service history. I know of two gentleman in Texas who have gotten repairs at least partially paid for by MB out of warranty
But again I have seen these cars with excess of 200K with no problems..

Warren
1992 300SD 113K
Columbus Ohio

Chris,

I got my 91 350SDL almost 6 years ago at 79 kmi. 'Few months later I noticed a "skip" at idle. MB dealer tech. showed me MB notice about the prob. at # 1 cyl. MB refused to "help" with repair. 'Few weeks later, I had decided to "bite the bullet" & get repairs done. Couple of days before appointed time to repair re. skip, timing chain broke at 89 kmi!! MB refused couple of times to help with repairs. MB finally paid 50% of parts. Much work to top of engine, new valves, lifters, guides, seals, shaved head, lots of stuff I don't remember. No work on lower part of engine. Car doing great since; now at 144 kmi. Fantastic car!! Best riding, best driving I've had! Hard to beat!!

Thanks Wilton I am hoping that I will eventually hear something better than that about the engine or I fear I will be selling mine. Hearing this makes me wish that I would have kept my mint 85 300 D. That car will be around for a long time. By the way wilton do you have an estimate on the cost of your repairs?

Chris,

Total bill was almost $2700; MB supposedly paid a measly $600. The whole episode still makes me damned mad! I bought the car because of 300D's history of long-term dependability, etc. I was trying to get the latest I could "afford" at the time. Who would have thought "they" had screwed up a very good engine by trying to tweek it a little more & called it "350". MB has known it for years & they keep trying to deny it! 'Wish I had bought an 87 300SDL. Good luck.

Wilton,

It sounds like you fared pretty well if you ask me ....Some of the people with these cars(including myself) have needed
repairs that were in the $9-12K range
I even know of one guy who paid for his own rebuild(MB rebuilt engine was not available years ago when he needed it)to the tune of $8500.00 out of HIS OWM POCKET.He did get a brand new head which is of a totally different design he said
My car has a completely new MB engine(sans the turbo,but all parts from the valve cover down) and the dealer tech told me the there were some major modifications in the new engine versus the old.From the totally redesigned head to suport parts such as the engine mounts and shock.
The regional MB rep claimed no foul on MB's part with this engine.Because I had a heated conversation with him as to how this could have happened The problem,he said, was caused by lack of maintenance and bad fuel.....but two things are curious here...1.The immediate next day availablity of a complete MB engine for a car that was a very low volumme seller and 2.The myriad of design changes of the new engine versus the old...
I live in Columbus Ohio where there are probably no more than 3-4 W140 diesels in town and incidently there was another 1992 300SD that was also having the engine replaved at the same time as mine. That owner also paid totally out of his pocket(but I was told the dealer did the job at cost because he was a longtime customer)

My repair bill by thy way would have been $10,500
My work was done at Crown Mercedes in Columbus Ohio which I will say I am very satisfied with their service. My car has made them scratch their heads a few times..but they have seemed to have gotten it right

Warren
1992 300SD 113K
Columbus Ohio
turner@greif.com

Warren,

My repairs were only to Top part of the engine (head)& timing chain. The big problems with lower part of the engine haven't shown up yet.

Chris p.,

It appears as though you have a tough decision to make. In deference to Mr. Haney, I was not "blatting bad press", but attempting to help you educate yourself with regard to the history of this engine. BTW, mbz.org is a great and thoughtfully educational site that is maintained by a fellow MB owner (no affiliation).

Though I am a non-owner of a OM603.97 engined vehicle, I personally know of 3 individuals (they do not participate in this forum) that have one of these vehicles and ALL of them have experienced the aforementioned issues with this engine. One of them chose to replace the engine (his expense), while the others got rid of them altogether. Best of luck in your decision.

Chris,

Did the two people you know get rid of their cars as is?..and therefore take the financial hit,which I assume was tradein value less about 10-12K?....were they the original owners? were they maintained by MB dealers?
This is a starnge problem as there are many cars that never had the problem(mine not included) and have over 200K....
I think there was some design problem with this engine but it seem to be contingent on some external factors...that I don;t know....but the good new is My MB technition as well as the regional MB rep for my area say they have never seen this happen twice....at this point I have the MB dealer document carefully my maintenence as noone can say my car was not maintained correctly

Warren
1992 300SD 113K
Columbus Ohio
turner@greif.com

Warren,

I know for a fact that two of them had them religiously maintained by the dealer. Not sure of the other. Those that chose to get rid of them traded them in as-is.

Thats a drag Chris...because I gotta tell you unless my car had a zillion miles on it MB had better offer me some help if my engine ever has problems again...because no excuse can be made by them as to my maintenance...
In regard to your friends who traded in....I can only imagine how little they were offered...but I guess they figured just take the 10-12K hit and cut their losses?
Thats a shame because after owning a 1985 300Sd and a 1992 300D I can say this car I presently own is probably the best driving/riding car I have even driven and also probably the most civilized diesel(although the 1992 300D was a close second)

I really love this 91 sdl and I have a hard time believing that this engine is doomed to a premature death. I am going to bring it to my mechanic and see if he can detect any problems at least we now have an idea what to look at. It really runs well burns no oil and is smooth and quick for a diesel car of this size.

Chris,

You may never have a problem,I have heard many people never do....and for the 3.5 diesel I agree its a very civilized auto....light years ahead in power and refinement over my old 1985 300SD......buy I have a buddy that just bought a 98 E300 tubodiesel and I hear its even more incredible
I am sure you will throughly enjoy your new vehicle


Warren
1992 300SD 113K
Columbus Ohio
turner@greif.com

I don't think that I can afford a ride like that. The other thing about a car that new is that they are too civilized I don't want a car with charcoal air filters and all that. I have been thinking that I would like too keep this one for quite a while. I would really like to put the European headlights in it.

Chris & Warren:

I have both a 94 S350 and a 99 E300. I love both cars, but the S350 is a very expensive thing to repair. Just recently my a/c went out and it looks like I'll have to replace the stuff in the dash.

Also, the chain guides broke and the chain beat a hole in the valve cover. I'll post a pic if you wish.

Oh and my self closer system goes away for a while sometimes, but removing the fuse seems to solve the problem for a month or two.

Now, having said that, it is a wonderful car to drive on the highway. Very very comfortable. Drove from Pittsburgh to Iowa straight on one tank.

My 99 E300 is a very different vehicle. Has different bells/whistles. Very quick and very quiet. I have about 69K on it in about 2.5 yrs. It has been hard to align, but now I'm used to it.

I replaced an 84 300D (with 328K) and an 84 300SD (with 192K) with these 2 cars. I don't know if I'll get the same longevity, but have my fingers crossed.

Good luck!
Neil.

99 E300D
94 S350D
83 500SEC Euro

Neil,

I can second what you say about expense on the 140 body...in the two years I have owned the car...it has had replaced...1). Complete engine 2. AC evaporator core 3.Dash climate control push button unit 3. Closing assist pump 4.Alternator...5.Front bushings,control arms and other front end parts...many other small items while the tech was in there and saw items that needed attention
Total repairs costs to date... $22K(90% warranty)The evaporator core was done before by the original owner in 1997 by the way as was the instrument cluster replaced because it shorted out...as I hear was common in the 92-94 models
Its almost a joke at the dealer where I go because other than a transmission and AC compressor just about everything has been replaced and is now under MB parts and labor warranty. I have had two TENSE discussions with the regional MB rep...and his reply is "these 140's are VERY VERY expensive to repair and as they got older things will get worse".....that statement makes me wonder what will happen when the cars are worth in the 8-10K range and those repairs are no longer financially practical considering the cars value at the time
The car is so complicated I would be afraid to let anyone but the best independent shop(which I don't think there is one in my area) or the MB dealer

Warren
1992 300SD 113K
Columbus Ohio
turner@greif.com

Future value is definitely a consideration.

Perhaps I'll trade it in instead of getting the a/c fixed.

I'll have to think about it....

I can say this the 350 sdl has problems I have it. However, this engine can be nursed. You will have to bite the bullet at some point, but there are certain things you can do. Some were fabulous, but more than an unacceptable number were lemons. The original problem was not just the weak rods. The original problem was related to poor quality control with the heads at the foundry. There was a small crack at the water jacket that was not repairable because it could not be reached to reweld. The rods (not being stout enough) exacerbated the problem because in some case liquid not steam coolant would get into the cylinder ...vapors compress liquids don't. this would cause an extremely high compression ratio that would in turn bend the rod thus causing an elipitical wear in the cylinder thus causing more oil consumption due to blow by. As long as you replace the coolant and flush the coolant system annually(oil gets in it due to this) also replace the hoses the oil tends to have fuel in it and eats the hoses from the inside out, repalce oil every 3,000. ensure that there is alwasy plenty of coolant because you will be losing some in the compression chambers and watch the crancase oil. If it is black good if it looks like a coffee milkshake you need to bite the bullet and replace the engine... do not rebuild. The cracks in the head, due to the temperature cycling ,tend to get worse thus causing coolant to get into the crank. A tell tale sign if this engine has this problem is if you see a minor oil slick or oil residue in the coolant reservoir . Many MB techs originally fixed this problem thinking it was a blown or defective head gasket. I have seen these defective heads magnafluxed and people still miss this crack. This engine, since 1995 out of MB is solid. Better coolant channels, better rods and a better match on Rockwell hardness between Cylinder, ring and piston. MB spent millions redesigning this engine, a rebuilder is working with a block and cylinder wall that are also part of the equation and original equipment the new blocks meet different specs. $4000 to buy plus $5000 for a new engine if your nice to your dealer and $1000-$1500 for pull and installation with a reasonable local mechanic and you are back in business. The turbo is your only wildcard and if a turbo is driven correctly it won't wear out. Always idle the car for 45-60 seconds before cutting of the engine. Don't rev it it can get upto extremely high RPM's and then if you shut it off it it has no oil flow and is still spinning fast. One of the most important rule of the old oild cooled turbos that noone ever talks about. I would buy it because with proper records you can break even on the money versus resale and one helluva car to boot. I hope this llong diatribe helps and doesn't bore the pros in this forum. Good Luck.

where did you get these engine prices?....a rebuilt MB 603.971 is $8500.000...evean at a discount you may get one for $7000.00...

$1500 for r/r sounds accurate....and it comes with the 48/50 complete MB warranty good at any dealer

interesting thing I noticed with the new engine(and I have heard others say the same thing)...the new engine is louder than the old one....beefier parts make more noise?

Warren
1992 300SD 142K
Columbus Ohio

Sir, I have seen this engine sold for just over 5,000 if I remeber it was 5032. I my self have paid 6040.00 for this engine with the full warranty as a long block. So, it is not unreasonable if you have a good relationship with your dealer. I have talked with Crowne in Columbus as I lived in Bexley at one time, but I always got better deals from Potter. If you have any questions please let me know. Best Regards.

For an $8500 list part $5000 is quite a deal....was the engine you bought from a MB dealer?...I have seen some cheaper rebuilds but I was unsure....as for Potter Versus Crown...I tried to buy a car at Potter once adn their prices are rather high..in fact I was so turned off by the bargaining experience I said that once I did get a car I would never go there for service...Crown has done 95% of the work on my car for the past 3 years and I am for the most part satisfied with them....where did you buy your car btw? and who did your engine work?
Crown did mine

Warren
1992 300SD 142K
Columbus Ohio

I purchased my 1995 E320 new from Ross in Dayton. They have also been very pleasant to work with and i find that they are extremely helpful. As for my my 126 I purchased that from the Auto Livery in Ross, Oh. As for the engine I deal with an authorized independent, who was formally with a delaership. The engine is a Mercedes with the full 48/50 warranty. BTW he only charged me 800 for the pull and place of the new motor. However, I also replaced all hoses, radiator, expansion tank, transmission cooling lines and motor mounts. Total bill for this with the new motor $8,160.00 out the door. I have been fortunate enough to find an independent who is authorized to sign my service book. Drives the dealers nuts. This was a long block with the belt on it. It included alt., p/s pump, a/c comp., injection pump and oil in it. This was just done this last month.
I only us MB parts I have found that although many companies are authorized oem aftermarket that MB has tighter quality control. Shoot, I only use MB antifreeze and brake fluid. Oil is negotiable,depending on the mileage and condition of the engine. Pay a little more on average I figure it to be about 20% more. However, when only spending on average 3,000 per year on maintenance I am not worried about $600.00. I save a lot because I do most of my own wrenching. My 126 has 227,000 and it has had this problem I know, since the 70,000 mile mark when it got its first headgasket. Like I said previously, a lot of MB techs thought this was a bad head gasket. I bouught the car with 207,000 on it knowing I would have to go down this road. I just wanted that diesel, because I drive 70,000 per year. I expect to have to buy another engine in 6-8 years. That s cheap in my book.

As for buying a car from one of these dealerships I agree the bargaining experience is rough at Potter's, but i find their service techs and parts people more than fair. I will say I can call every dealer in Oh and they will all have different prices. I find Crowne to be right up there with Dana in Cincinnati. Dana wanted List price $8,074 just for the motor, but they are known for exagerating not only prices , but problems. I would highly recomend that anyone going down this road DO NOT use anything, but an MB engine. Not worth the risk and a great warranty. I hope this helps. I will be honest if you were charged $8,500 for a long block I would be reaming that service manager, because they charged you more than list. If you go there for most of your big work, they should have at least helped you on the engine price. The standing joke when you ask for the engine price from the dealers is this. " Let me guess I only need one guess... a cracked head?" These dealers know that the old engine (first version) is a lemon period. I find it offensive that they feel they should make 30% gross profit on the engine. Alas, not MB of old they are not worried about owner loyalty anymore. I feel that ended in about 1996 now they just want to sell cars. Leasing is the only way most of these people could afford to drive a new MB. If any other questions, let me know. Best Regards

BTW Joe Sabo in Cincinnati did the engine work. Heck, I didn't even give the guy credit after everything he does for me In the previous novel, I mean post.

It does sound like you have a lot of expereince with the dealers here in Ohio.I moved to Columbus in 1997 from Dallas Texas and was used to dealers that were 3-4 times the size of the dealers here...so I had to get accustomed to different practices here....two years ago my engine was replaced...and like you it included water pump starter..etc..etc...much of mine was covered by warranty..thank god...as was the $5100 evap core, dash pushbutton unit and blower resisitor repair that occured about 3 months before that...all of my service except a recent brake job and fan clutch repair has been done by Crown...Crown has done about $20,000 of work on the car(mostly warranty) since I have owned it
The techs at Crown told me that they have done a few short blocks on 350's that have come thorugh their shop.Curiously at the same time I was haveing a new engine installed there was a blk 1992 300SD as Potter MB having the same exercise done...althought I think that gentleman's car had mileage in the 140's at that time...its funny because at the time I had a heated conversation with the MB service zone rep and he PROMISED me that he had NEVER seen anyone have problems with the replacement engines...time will tell I guess

Warren
1992 300SD
Columbus Ohio

Warren, you seem like you are very interested in keeping that diesel at top notch like me. Shoot me an email I have come across a few tips out of the engineers in germany when I was there last month. jwii@zoomtown.com BTY MB north america agreed to give me 100K mileage warranty on my engine as I drive about 50K per year. Best Regards. JW

May we all "hear" the tips from the engineers in Germany?

you can e-mail me at ....turner@greif.com....any tips that you might have......how did you get MB to give you 100K warranty!!..very interesting...I have had several "heated" discussion with the regional MB rep....and he didn't give me 100K warranty...as for the engine I think list is about $8600.00...hard to tell what they sold it to me for exactly...I think something in the 7,000 range...but had warranty paytment involved also...and also some exploration/inspection charges that the warranty company wanted done because of the size of the claim...espacially since they just paid a $5000 A/C claim just about 3-4 months before the engine problems


Warren
1992 300SD 143k
Columbus Ohio

Interesting fact that you mentioned also earlier JW is "do not rebuild"...when you have problems with this engine.......The cases that I have seen where the car was still under MB warranty(new car or starmark) they have replaced the shortblock of the car and kept the existing head and turbo intact...I do know of one case where the gentleman had 65K miles...MB paid half of a 13K repair bill


Warren
1992 300SD 143K
Columbus Ohio

The biggest tip I received was what to put in your fuel to keep the intake side clean. I got to see an example of an engine that had this done. You can only do this if you do not have a trap oxidizer or a other exhaust side polution control devices. Doing this will kill those devices. You put 1/2 of a quart of desxron III tranny fluid in every other tank of fuel. Does not have to be expensive go to a place that sells the stuff in gallons. Buy it cheap. The car tends to smoke a little more at start up, but does not affect performance. They showed me intake valves that had not been cleaned and they had cycled for over 2,000 hours equivalent of roughly 80,000 miles. the metals had darkened, but they did not have any carbon buildup! Cool stuff. The company I work for works with Bosch, Cummins, Caterpillar and Siemens and I have asked almost every engineer about this and they all said the same thing. With all the detergents in the tranny fluid it keeps the intake superclean and it doesn't have any of the crap that injector cleaners do that can make the head just a little bit hotter, while using it. The second thing that they were telling me about was the original problem with the rod design was it needed better lubrication. The second generation rod had an additional hole in it for lubrication and they were made a shade heavier. The other thing is the new engine has a different head configuration. They also said that when having the engine put back together make sure the shop does NOT use silicone based gasket sealers. they recommend loctite 518, since if it (loctite 518) gets in the crank it won't kill the overhead oiling system. The other thing is there is a recommendation to have the front of the car 12" off the ground when you bleed the coolant. This is in the form of a TSB that most dealers and techs don't know about. Also, 55% Distilled H2O and 45% MB coolant.


Best Regards