Engine squeaking video
Engine squeaking video
Any help diagnosing is appreciated.
It's new. There's no new changes to the vehicle, no new parts, squeak only showed up a few days ago.
I can feel a small amount of wiggle on the supercharger tensioner pulley but it really feels minimal. Most other pulleys feel tight.
I've only wiggled them with the belts on and tensioned so couldn't really tell much but just thought I'd post a video and see if any seasoned guys were familiar with it before I went fishing with tools.
https://youtu.be/bNnwVGYjsaE
Last edited by Style_Front; Mar 11, 2018 at 03:21 PM.
Senior Member
Joined: May 2007
Posts: 276
Likes: 30
From: United Kingdom
CLK56TT (WIP), S65, RR 5.0 S/C
That sounds like a shot bearing to me. Take a screwdriver (or an auto stethoscope if you've got one) and listen next to moving parts. Or get someone with a mechanical background to do it for you if you're not technically inclided.
Senior Member




Joined: Sep 2017
Posts: 499
Likes: 66
From: N.Y. L.I.
04 E55 AMG BLK/BLK(MyDD), 06 CLK 500 (wife's) 07 ML500, 2012 C300(son's)
bearing +1
My first guess is the idler pulley. Since I've done one on both my W209 M113 and W202 M112
Last edited by Pmarino; Mar 11, 2018 at 04:37 PM.
Remove the SC belt and start the engine, if the sound goes away.
Then a mechanic stethoscope will be handy to find the offending bearing. Check idle pulleys in particular
Then a mechanic stethoscope will be handy to find the offending bearing. Check idle pulleys in particular
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MBWorld Fanatic!
Joined: Jan 2016
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
Removing the belt and spinning each pulley by hand might show you which one is the offending unit, but yeah: It sounds like a bearing is dry and getting ready to seize up. Fix it before it tears up your belt and leaves you stranded...
Idler pulleys can easily be spun by hand and should make zero noise. If the bearing is rough you'll feel it and hear it.
Idler pulleys can easily be spun by hand and should make zero noise. If the bearing is rough you'll feel it and hear it.




