HUMMING/WHINING NOISE WHEN DEACCELLERATING
Thread Starter
Senior Member
Joined: May 2008
Posts: 477
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From: Maricopa, AZ
2012 S63, 2013 E350 Bluetec
HUMMING/WHINING NOISE WHEN DEACCELLERATING
At freeway speeds, if I let off on the gas pedal to slow down a little (just coasting, not braking), there is a high pitched whining/humming like noise coming from the back of the car. Been doing it for awhile, but doesn't seem to be getting worse. It is very faint, nothing loud.
It's on a 2002 S500 with 92,000 miles.
Anybody got a clue what this might be? Differential?
It's on a 2002 S500 with 92,000 miles.
Anybody got a clue what this might be? Differential?
Thread Starter
Senior Member
Joined: May 2008
Posts: 477
Likes: 30
From: Maricopa, AZ
2012 S63, 2013 E350 Bluetec
No, it is not a 4Matic. Didn't even think of the catalytic converter. Car has 92,000 miles on it. Will check that out the next time it's in the shop.
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Joined: Jul 2006
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W221
I had similar sound under similar conditions (when letting off gas at highway speeds) on my '08 S550 coming from the front (my car is 4 matic). Turned out it was caused by damaged joint of the prop shaft. If I remember correctly the explanation by the tech the noise had something to do with the joint being fully engaged when under the load (and not making noise) and then getting looser and making noise by damaged components when I would let off gas. In any case the noise went away after prop shaft was changed.
Last edited by eugeneC55; Jul 21, 2014 at 12:28 AM.
