08 Mercedes C350 New Belt Squeaking

mxchris727 · 05-16-2019, 12:10 PM

Hi All,

My buddy has an 08 C350 that has a rhythmic belt squeak. I have put two new OEM Continental belts on with no change to the sound. As you can see from the video, the sound is in time with the label on the belt. The pulley bearings are fine, so I can't figure this one out. Any ideas?

https://flic.kr/p/2fQUh5u

Thank you!

overcoil · 05-16-2019, 12:48 PM

Been a few years since I worked on my 202 and 203 c-class but belt tensioner seemed to need replacing as if a wear item - but my belt tensioner squeal seemed of longer duration then in the video but I might be mistaken

chassis · 05-16-2019, 10:52 PM

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yco · 05-16-2019, 11:42 PM

i never did it by myself but there is a way to check why there is a squeak on the belt and actually most of the time belt is not the reason..

spray some water on the inner side of the belt while engine is running of course.. if you start to hear squeaking higher it has to be a tension issue.. if squeak wont get higher, take out the belt and turn the pulley bearings should turn pretty smooth without any noise and any slack (a bit is ok).. a small slack can cause the noise also..

if its a tension issue after adjusting it to factory setting dont forget the run the engine for at least 5 mins and check it again.. so tension adjusting needs to be done twice not once.. if there is still a sound, tensioner pulley needs to be changed and tension shouldnt stay the same of course after few seconds.. better go for OEM belt also.. it should help you out.. and if there is still some noise turn off the engine and run away from that car..

05-16-2019, 12:10 PM	#1
mxchris727 Captain 195 Rep 665 Posts Drives: '03 M5, '06 325i, '12 M3 Join Date: Aug 2012 Location: Westport, CT iTrader: (0)	08 Mercedes C350 New Belt Squeaking Hi All, My buddy has an 08 C350 that has a rhythmic belt squeak. I have put two new OEM Continental belts on with no change to the sound. As you can see from the video, the sound is in time with the label on the belt. The pulley bearings are fine, so I can't figure this one out. Any ideas? https://flic.kr/p/2fQUh5u Thank you! __________________ BMW GT1 (INPA, DIS, WinKFP, ect..), ISTA/P & /D is up and running! PM me if you want to stop by and code your car.
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05-16-2019, 12:48 PM	#2
overcoil Major General 3121 Rep 5,582 Posts Drives: M235i 6spd Join Date: Dec 2013 Location: Mid-Atlantic iTrader: (0)	Been a few years since I worked on my 202 and 203 c-class but belt tensioner seemed to need replacing as if a wear item - but my belt tensioner squeal seemed of longer duration then in the video but I might be mistaken
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05-16-2019, 10:52 PM	#3
chassis Colonel 7986 Rep 2,491 Posts Drives: 9Y0 Cayenne S Join Date: Mar 2019 Location: Einbahnstraße iTrader: (0) Garage List 2020 Porsche Cayenne S [7.69]	mbworld dot org
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05-16-2019, 11:42 PM	#4
yco i'm just saying 6019 Rep 2,634 Posts Drives: E71 X6M '10 (sold) Join Date: Jan 2018 Location: Istanbul & Kyiv iTrader: (0)	i never did it by myself but there is a way to check why there is a squeak on the belt and actually most of the time belt is not the reason.. spray some water on the inner side of the belt while engine is running of course.. if you start to hear squeaking higher it has to be a tension issue.. if squeak wont get higher, take out the belt and turn the pulley bearings should turn pretty smooth without any noise and any slack (a bit is ok).. a small slack can cause the noise also.. if its a tension issue after adjusting it to factory setting dont forget the run the engine for at least 5 mins and check it again.. so tension adjusting needs to be done twice not once.. if there is still a sound, tensioner pulley needs to be changed and tension shouldnt stay the same of course after few seconds.. better go for OEM belt also.. it should help you out.. and if there is still some noise turn off the engine and run away from that car..
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