Found a really nice 350SD, 121k blue/parchment. Perfect condition in and out
new michelins, repainted wheels, all records. Here's the rub. I've read all the negative press on the 350 engine. This car runs perfectly now, but last year
it came to a halt with a broken timing chain. I spoke extensively with the tech
and the sercice manager at the shop that did the repairs and they swear that only four valves were bent when the chain broke. No damage to the piston crowns was seen. They did a complete valve job with new guides, seals, seats etc and new timing chain components, also put in new glowplugs
poly belt and accessories. Spoke to the machine shop that did the work and
they said it pressure tested fine. The car has no history of overheating, but has a new radiator as insurance policy. The engine purrs and drives perfectly
with no indication of a bent rod or two, and I've driven a 350 with the rod problem--you can tell by careful listening. The question is, do I go for it or pass. His shop has about thiry high end newer MBs, so they seem to know what is happening. I expected it would be priced around 13k, but I think I can get it for far less. They sure are nice cars and I can see why lots of
people think the 126 was the best of the "classic" Benzes. There's nothing else that comes close to the whole package, but I really hate to get burned if I have to re-fix that engine.

Steve

You already know the answer to this post.

There is just no way to tell if one of the original rods is going to last one week or 15 more years. Nobody has ever figured out the exact reason why some engines will bend their rods and others will not.

Life is short. If you are a gambling man, and can accept the consequences, then roll 'em!

I have a 91 350SDL and am having a new engine built for it as we speak. I love the car.

Who knows when something is about to give out? Anybody for an Morton Thiokol engineer's ok on a Challenger O-ring??

Have had mine for a year now, it's the best car I have EVER owned. Engine is perfect (po was anal about it) oil samples show no wear metals or contaminents out of the ordinary, 25 MPH, great acceleration, etc. The 350sdl is the pinnacle of mb diesel technology before MB went bonkers with electronics.

Uses NO oil between changes (about 3300 mi). touch wood... heh, heh...
just in case

__________________
71 220D 169K wrecked
83 240D 118K sweet 4 speed
91 350SDL (one of the 60% good engines) 156K
84 300d (loaner to my sister) 189K
79 300SD (partswagen)
86 420SEL partswagen
70 220d (partswagen)
68 280s GASSER!!! under construction now
85 300sd 310K miles winter beater car retired
93 300d 2.5 turbo 168K wife's car
83 280SL euro 5 speed 155K
69 250S newest project 54K

We are all interested when one of these engines has "issues". Can you provide any more details of the situation?

I suppose it is unjustifiable to expect that a car that cost 60k+ when new wouldn't have an expensive issue 15 years later. I wonder what the numbers actually are on the rod bending, ie. how many of the total production of 350SDs developed bent rods as opposed to the number one would expect from a normal production run. Probably no way to find out. Also interesting
that MB would deny a problem existed if it were verifiable. It would be easy for MB to do some follow up research with the relatively small mumber of cars
we're deaing with to see if something is really amiss or if MB customers are just noisier than others when it comes to their cars. I guess if your reputation is based on claims of superior engineering and manufacturing,you'd better be ready for some heat when something like this crops up.

As far as the particular car I'm looking at, I'm probably more concerned about the head work holding up than a rod bending. Also the PO was a huge smoker and the smell is not going to come out of the otherwise perfect interior very easily. What amazed me most though is how nice these 126 bodies are. I allways kind of ignored them as being a little too big, but now I regret not
getting one a long time ago.

Steve

I also have a 91 350 sdl and love the car. Mine has 240,000 miles on it and it burns no oil and runs perfect. When I first got it I was told of the rod bending issues and it worried me but it has not been a problem for me and I really love the car. For long trips you cannot beat the ride and mileage.

__________________
91 350 SDL
91 300 E
85 300 D (sold)
79 300 CD (sold)
91 300 CE

When I bought my 350SDL, I knew that it had not been serviced as one would hope. The Transmission was gone but she ran fairly decent. I didn't have to pay a lot for her and put a rebuilt tranny in it. Drove it another 10000 miles. The engine had that surge in it and would go thru belt tensioners like crazy. One morning after cranking her, I heard a tick going on. I knew something was up... Before I knew it she blew the engine. I was able to coast it into the driveway of my office and that is where she has sat until now. I love the ride and mileage that she gave. They are big boats and are comfortable. I figured it was best to go ahead and put another motor in it and drive it some more because Diesels of that size and fuel economy are hard to come by. My Jag only gets about 12mpg around town. The 350 got about 25 - 28.

This does not sound like the typical bent rod that slowly ovalizes a cylinder and results in massive oil consumption. Have you been able to tell what exactly failed on the engine? Did it lose oil pressure or did it have a catastrophic mechanical failure?

What is known--the engine quit running suddenly. The shop that had serviced
the car said the car would crank, but the cam would not turn as observed through the oil fill hole in the cam cover. The shop that bought the car and did the repairs and is selling the car said the timing chain broke and the extent of the damage was limited to four bent valves, chain, guides and sprocket. What is unknown is the damage to pistons if any, or the general condition of the car, except I saw all the records. The car was meticulously maintained according to the books.
What to do...

Steve

Thats strange I have never heard of a 350 breaking a chain? Maybe the vac pump dropped its bearings into the chain?

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

That sounds more like it. They also replaced the vacuum pump in the reassembly.

There was a service memo about early chain failure in the 350's seems they were poorly made.

I hope you guys don't mind a partial hijacking, but I could use some serious advice.

I'm going to look at a '91 350 SDL tomorrow. Asking is just under $7K. No mileage listed in the local advertisement. I can look at body stuff and get an idea bout maintenance and stuff but I have NOTHING for diesel knowledge aside from the serious lack of spark plugs.

Go some pointers? How much should I be willing to put into the car if its in reasonably good shape, $2K, $5K? More? How much? I'm pretty good at budgeting (except for my first bout of MB madness...), so if I set a ceiling I'll stick with it or sell it.

Thanks in advance.

Botnst

If the car is in "good shape" you'll pump another $2,500 plus to get it in great shape. If the rod's haven't been modified and go bad, you'll spend $7k on an engine, plus the investments that you've pumped into it plus the purchase.