The best bang for the buck is to find a good used 380 engine that tests (when hot!) with good compression AND already has a dual row chain. But you want to look for a sedan engine, when you say "SL" people see dollar signs.
The shortest anybody so far seen a chain break at is 34K mi.
Your engine is destroyed. These are interference engines and the pistons and valves bang into each other. Best case you bend valves and gouge pistos. Worst case the valve ead breaks off and gets mached into the heads ruiing them and the block as well.
Keep in mind only the US got single row 380's and only for a couple of years.
Here you have suggested an 80% probability. Four questions ...
1- approximately how much to repair?
2- could the engine repair costs be minimized as soon as you hear the slapping noise of a loose chain to turn off the engine? Or are you basically screwed no matter what you do?
3- assume you are faced with replacing the engine - are there other alternatives than another 3.8L engine?
4- What are the probabilities of a well maintained engine lasting for 200k miles?
Thanks for your inputs. I was restating the issue to make perfectly clear your position which is that the 380SL with single timing chain is an inherently unreliable design but reliability is greatly improved if converted to dual timing chain.
What bothers me is that two mercedes reps have told me that the single timing chain is not that important an issue. One stated that many have gone over 200k without problems, and another to do regular oil changes and just get the timing chain replaced when my car reaches 75k miles as a regular service item. Shit, it Mercedes Benz feels like this is as big an issue as many on the internet, you would think that they would stand behind their product with a recall. Recently, Toyota sent me a letter about peoples questions about oil sludge concerns and Toyota extended the warrantee on engine sludge to eight years. Surely one would assume a Mercedes engine to have higher reliability than a Toyota - well maybe not.
Toyota was dragged kicking and screaming to settle the class-action suit involving late-model, low mileage cars that had engine failure despite proper maintenance, due to a design defect. For five years they had stonewalled!
Welp, at least Toyota came around and backed their engines and Mercedes is not going to acknowledge a problem. The net result is that I won't purchase anymore Mercedes but likely will purchase another Toyota.
So, both Mercedes and Toyota did not want to do the 'right' thing --- its that we let Mercedes get away with it?
Seems to me that the Mercedes engine problem is more serious than the Toyota oil sludge problem. In any case, the letter I got from Toyota was written like they were doing a 'community service' or the honorable and right thing for their customers. I guess its all how good one is wording things. BTW, has Mercedes even made a public acknowledgement about their engine problem?
Well Mercedes has a closetful of disgraceful issues like this. The "Bicycle Chain" motor. The whole 3.5 liter Diesel engine program 1990-1995. Derfective oil pump drive gears 1974-1976 280 with M110 engine. Windage tray breakage
300D/SDL 1986-1987. AC Evaporator failure all mid-nineties Mercedes models. Head gaskets all twin-cam inline engines 1990 on up. And there are more.
You'd think they'd do something about the ovoid bores in thr 3.5L diesel, too, but no. OTOH if you have an unrepaired 107 chassis they will still to this day fix it free, same as the trap oxidizer problem. They're weird about what they'll fix and what they won't.
MERCEDES STATEMENT START: "...all we are saying is that it is impossible to predict timing chain failure. There are too many vairables (age, mileage, usage, driving conditions, etc.), and because of this we do not provide a listing, or recommended mileage for replacement. We now only provide a double-rolling chain because we used it on the new 6 and 8 cylinder engines after 1985. Because it is retrofittable for the previous engines, why supply both? It is simply an evolution of parts. We don't feel the single rolling chain is a "time bomb", it was a very effective design, and yes many have lasted (according to owner reports) in excess of 200,000 miles."
MERCEDES STATEMENT END
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Mercedes seems to be telling me from that statement that:
a) the single row timing chain
b) Its a very effective design
c) Its not a "time bomb"
d) That the reason fro going to double row chains is simply to cut down on inventory of parts
e) that "it is impossible to predict timing chain failure" and "many have lasted in excess of 200,000 miles"
Sounds like Mercedes is saying this concern about 'single row timing chain" is all hype. I wonder if the 'data' on these engines will support their stance and that is the reason I requested data to support their position that the single timing chain is not as big a concern as many feel.
YOu are beginning to sound like a troll pretending to be a little dense.
I would suggest you believe whomever you please in regards to your timing chain, and we will gladly give you all the advice you need when it comes to changing your engine. Until then the engineers, mechanic and mercedes enthusiasts and 380 owners, with hundreds of cumulative years of experience and no vested interest in the answer, will continue to state, "Single row chains are a time bomb and may go at any moment, change them as soon as humanely possible before destroying your engine."
MB will continue to prevaricate, you chose whichever statement suits you best.
Jeremy, I'm not trying to act like a troll or act dense. I have two opposing opinions I am trying to reconcile with and even though one would think Mercedes would be the definitive authority, I am at least giving a lot of respect to the opposing stance. I have no desire to throw away $4 G's to install a dual timing chain in an engine that seems to 'purr like a kitten' unless I have to. I have to weigh these two opposing positions and potential costs. Perhaps Mercedes has even opened themselves up to a class action lawsuit if enough data can be obtained. I'm kinda pissed about this as I purchased my 380SL thinking I bought a well designed, well engineered, and highly reliable vehicle. Why the h*ll would I pay $45K for a car that is a piece of crap. I remember well when I purchased my SL that I seriously considered the 1984 Corvette at 1/2 the cost I paid for the SL. I guess I should have instead bought the Vette and have 20 G's more in my pocket.
I assume those of you who advocate converting to dual timing chain believe the
380SL engine should then be reliable to 200k miles if well maintained.
400,000 miles should be attainable with proper scheduled maintenance. If you really want to believe MB, it is your choice. That year corvette would have already consumed the extra $20k and not be worth more than $4k, rides like a pig and is what it is, a cheap sports car.
Where did you get the $4k figure?
If you are so unhappy with buying the SL, I will take it off your hands for $6k and change the flaming chain myself.
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