The engine of my 1982 380sl with app. 180K mile on it recently started
running rough and making a rattling, sometimes clanking, sound when
it's cold; in fact, the colder it is, the noisier it is. However, the
noise always goes away after a few seconds, once the engine is running
smoothly, and the engine runs great otherwise -- except that it
smokes until it reaches operating temp, probably due to worn valve
I replaced the valve stem guides myself at about 100k miles, along
with the upper chain guides, tensioner and chain, though the engine
wasn't making any noise at that time.
My questions are:
1) Is there a way to tell the difference betweeen "chain slap" and
noisy valve lifters, since -- AFAIK -- both usually go away after the
engine is running smoothly?
2) Since I don't have a garage anymore, does it make sense for me to
have a mechanic check for chain stretch, or should I just have him
replace the chain, given the cost of checking it and the car's mileage
2a) If so, should I get the chain directly from MB, or is an
aftermarket brand, like the IWiS from the Benzbin, just as good?
3) When he checks or replaces the chain, is there a way to check
whether the chain guides and/or tensioner need to be replaced, too, or
should I just have him go ahead and do that to?
4) I heard somewhere that the lower guides rarely break, but should be
replaced at app. 200k miles anyway, Is that really necessary, given
the cost this would add to the jobl?
5) Finally, when I was under the car a few days ago, and a friend
started it up, I heard a whirring sound that seemed to be coming from
the oil pump until the engine warmed up. As it sounded similar to the
one my old fuel pump made before I replaced it, I was wondering if my
oil pump could be going too. I'd hate to think that it was, since I
understand that getting to it requires dropping the undercarriage.
Does anybody happen to know what the typical life of the oil pump on a
107 is, and what, if any, symptoms, a failing one demonstrates?
Thanks very much in advance for any help anyone can give me answering
any of these questions -- especially Karl , Tiger and the other
Best wishes to all for a happy, healthy, prosperous and MB-
problem-free New Year,