1987 560sl has a squeal/whistling type noise on acceleration. Most noticeable when at 20mph and accelerating to move into a fast lane or adding power for a hill. My mechanic has been stumped by this one--but he does not have a dynameter and cannot recreate the noise on the floor even though he hears it when test driving. It is not the belts, though to my ear it sounds like a belt squeal. If it is a failing bearing it wasn't discovered in the shop using stethoscopes. Possibly a very small vacuum leak? I agree that the next step should be to find a shop with a dynameter, but if anyone has had this problem I'd be interested in hearing about it. Thanks!

John C
Oakland, CA

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John C
1987 560SL 109,000 miles
2001 E320 103,000 miles
2007 E350 32,000 miles

JohnC,

I had a similar symptom on my 240D when it was relatively new, and it turned out to be a pinhole in the exhaust system that would, under certain rpm and throttle conditions, whistle, and very loudly at that. I found and patched it, but the patch did not last too long and I ended up replacing the section of pipe with the first near 90 degree bend. That took care of the problem and even when that pipe began to fail I never got the whistling back. Hope that helps, Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

JohnC

I have a similar noise in my 380SL. But only when cold. Once it warms up, the noise goes away.

JimSmith could be right as to the pinhole in the exhaust system. I just had a new convt installed. Did not do it prior.

Hope it help.

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Marvin
1983 380 SL