Newbie w/Question about S350D??? - PeachParts Mercedes-Benz Forum

singnsave · #1 05-12-2007, 04:26 AM

Hi,

I've read alot of information from all of you....thank you for the education. Now I need some help.

I am looking to buy a '95 S350D, I really like the big car, with a smooth ride diesel. I'm looking at one that blew the engine and was replaced at 135k approx. 50k miles ago, "seal between turbo & cooling oil just broke while driving down the highway". There were several issues that were replaced apparently not due to actual problems with the car, but rather vandalism. So, now the car has a "remanufactured engine with upgrades and a new console and wiring harness. Doesn't go through alot of oil. I'm going to talk to the mechanic that's done all this work and was wondering what specific questions/answers I should be looking for.

Also, the A/C doesn't run cold, but the fan comes on. Tried last summer to put freon in it to see if it would hold, and it didn't. What could it be? Compressor? What could the cost be to fix? Again, I'll be talking to the mechanic, but really wanted to gain some insight beforehand.

From reading your posts I understand there was a problem with the rods in these cars, but would the remanufactured engine with upgrades help to eliminate that from continuing as a problem? I read somewhere that if the engine was replaced it should be ok. Also, read about the harness/wiring problems in the S cars. Could the new wiring harness eliminate that problem?

Thank you so much for your insight. Looking forward to hearing back from you.

singnsave
1984 300SD 290k

Jim B. · #2 05-12-2007, 06:22 AM

But, since you asked....

I'd try and find out EXACTLY what kind of engine was put in the car.
Was it a independent shop's mechanic or a Mercedes Benz dealer who put in the new engine?

Was it just a remanufactured motor, and if so, did it have the upgraded connecting rods in it or not?

The best scenario would be a brand new crate, long block motor installed by a Mercedes Benz dealer. It would have all the upgrades and be new.

But......even in that case, it's very possibly a losing gamble. While some members here report satisfaction with these cars, generally the odds are against you, even with a new engine in it. You wouldn't know whether the new engine was good until it started burning oil, but by then,,,,,it would be too late.

The engine is called the "rod bender" engine, and is widely believed to have a basic design flaw, the Mercedes diesel engine to avoid. It's been discussed at great length here, search "rod bender" here to start.

Then there is the 1992-1999 W140 body you are looking at. While hugely safe, quiet and comfortable, they are hugely complex and VERY expensive to fix when things go wrong, such as the AC evaporator, which requires removal of the front dash and seats just to access and fix, over 22 hours of labor required, it can be thousands of dollars, very quickly. It sounds like the car you are looking at, has this $3000+ issue right NOW. I wouldn't be surprised if that is the reason the owner is selling it, so he won't have to deal with it.
With some dealers charging $150 per hour, a 22 hour job is gonna cost a LOT!

The electronics, soft close doors, and other complexities make them a VERY expensive vehicle to keep up.

Frankly, a W140 diesel 3.5 car is, in sum, very likely to be VASTLY expensive should you get a poor example, and the odds of that are VERY high.

I wouldn't personally buy one, under ANY circumstances.
I'm not even going to ask what the price is. I woouldn't want one even for free!

Rather, I'd look for a beautifully kept 1981-85 300SD or an '86-'87 300SDL that was rust/accident free, with books and records, in a color I liked.
Those are proven to be good, dependable, long lasting vehicles.

dukegrad98 · #3 05-12-2007, 09:12 AM

What Jim B. said. I've posted on this a couple times recently, as that series was also my preferred vehicle. However, given the engine problems (and the fact that no one really knows if the "upgrade/replacement" engines were really any better) and the huge expense of an AC job, I voted to stay away. If you really want to stick with modern conveniences and safety, do what I did and shop the W210 E-class diesels. I've only had mine a month or so, but I have to admit I've enjoyed it for a couple thousand miles already.

There are lots and lots and lots of threads about the rod-bender generation of cars. Go read them...carefully. If you're like me, it'll make it much easier for you not to buy that car, even if you really want it bad like I did.

Cheers, John

singnsave · #4 06-22-2007, 04:25 AM

I wanted to buy a newer diesel, and the newest was the 95 S350D, but the warnings I kept reading has altered my decision. THANK YOU FOR YOUR INPUT. Thankfully I didn't rush into anything, I did my homework, researched it fully and then researched some more. It was difficult letting go of the emotional tie, but, now I'm free! I am considering an S500. I know it's not a diesel, but it looks EXACTLY the same as the S350D did without the rod problem. I am looking forward to a clean bill of health from the mechanic and then I'll purchase it. It does have a few quirks though, which I'd appreciate some help on.....
The passenger head rest sounds like the motor works but the head rest doesn't move.
The driver door doesn't lock, unlock, and the sensor isn't working, but the car will lock, unlock from passenger side.
Antenna sounds like it works, but nothing happens.

That's all I know for now until the mechanic lets me know what he finds out on Tuesday.

Also, the previous owner smoked. How can I get that smell out of the system and interior? It's not just the smell, it causes me to act like I have an allergy. Maybe I do??!!

Thank you for your helpful insight.

vstech · #5 06-22-2007, 09:05 AM

ICK, a smoker's car can be impossible to clean, if you react to cigarette smoke like I do, just walk away from that too... sorry, there is NO WAY to remove all the smoke residue from a true smoker's car. you can clean the seats, steam the carpets, and the headliner, wipe down all the glass, and trim, have the car visually spotless, then when the heat or a/c comes on, POW the smoke is right back where it was.
plus you still have the $3K plus bill for fixing any a/c issues.
I am gonna have to side on the stay away from this body style/age MB... sorry.

Rick Miley · #6 06-22-2007, 02:18 PM

There are plenty of S500s out there. Find one owned by a non-smoker.

sixto · #7 06-22-2007, 03:53 PM

S350 - ideally the new engine has at least a factory or Metrics Motors short block. Less ideal would be evidence that it was rebuilt with redesigned rods and new sleeves for the cylinders that had bent rods. In my case it made more sense to use the robust 3.0 block.

I'm more daring than most but I won't touch a W140 if AC doesn't work.

By chance do you have the VIN of that car? What are the 12th and 13th digits?

S500 - W140 gassers make more financial sense. You can get a newer year model or one with fewer miles for the cost of a Diesel. Try for a 98-99 S500 with 5-speed AT if you find 4-speed + second gear start as annoying as I do.

In 95 or from 95 the antenna is for cell phone only. The radio antenna is part of the rear window.

My 95 S420 came with a broken rod in the driver door lock linkage. Cheap part, easy to replace if you have two elbows per arm and can thread a needle with your eyes closed.

The only reason to avoid an M119 is if there's sludge under the valve covers. Make sure that gets checked during the PPI. And have them check the camshaft oilers while they're in there. If it's difficult to remove the lid of the oil filter canister, the engine mounts are shot.

I find the W140 thoroughly enjoyable to work on given this website, the V12uberalles website and alldatadiy.com. Note the masochistic tone in my voice when I say that. There's only so many W123 door lock vacuum pods you can replace before you need more of a challenge

Sixto
93 300SD 3.0 - comatose