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Discussion Starter · #1 ·
Hey guys
I bought this car yesterday and noticed on the drive home a loud pulsing noise. particularly when i braked into a 50km zone.
Today I finally had a chance to capture the noise.
it almost sounds like it's coming from the RH camshaft (facing the engine)

I have sprayed each of the pulleys and no change in the sound.
The car runs well and throws no codes.
no start up rattle or rythmic noise on cold start
It seems to start when brakes are used.
However this could just be the car getting into the rev range to hear the noise.
The braking system says "hold inoperable" now when pressed.
it changes with the revs but seems to stop after about 2k.
The engine is outside of the soft timing cog range.


any ideas?
i should also mention that it's actually louder in the car with the windows up then listening with the bonnet open.
anything would be appreciated.
I've spent hours searching.
I was told by the owner it did throw a code for a camshaft sensor but when cleared it has not returned.
thanks in advance
 

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Outstanding Contributor W221 Moderator
2010 E350 P1/P2, 2008 S550 Designo, 2002 ML320
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My thought is there's something in your timing chain path that is worn or in need of replacement. I don't see how many miles/kms you have on your engine, but a low frequency noise like that makes me think there's a worn chain guide or perhaps the tensioner has lost it's ability to take the slack out of the chain. This could be a tensioner issue, but I suspect that the chain has stretched to the point where it is just too much for the tensioner. This can be verified through a check of the engine timing marks on the camshafts and the crank.
 

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Discussion Starter · #3 ·
Yes unfortunately those are kind of my thoughts too.
The only unusual part is its quiet on first start.
Then seems to start (or I hear it) when the brakes are first applied.
I first thought it was a sbc pump but quickly learnt it doesn't have one. (I have an E55 as well)
The car has 105000km on it.
 
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