Mercedes 276 V6 petrol engine startup rattle

Mercedes 276 V6 petrol engine startup rattle

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355f

Original Poster:

516 posts

250 months

Thursday 16th May
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Dear All

I have what appears to be a rattle on startup for abut 5 secoinds then all runs perfectly- no engine checklights.

Can any one suggest a speaciliast in Cambridgeshire please


Panthro

686 posts

220 months

Thursday 23rd May
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Is this on a C43?
I am almost sure that this will be the turbo wastegates. It's normal, nearly all of them make this noise and it does not affect the performance of the car or the turbos. My C43 did 75k with this noise. I had it checked by a Mercedes specialist and a turbo specialist and they said it was not a problem.

You can get replacement 3rd party actuators but not OEM as Mercedes don't sell the actuators separately. If you go down that route it will be a lot of work for nothing other than getting rid of the noise.

Here is a recording of my old car:

https://youtu.be/h0_vxMzGEds?si=rh76B_IuoBxb1w8x

mwstewart

7,727 posts

190 months

Tuesday 28th May
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Check the codes as there may be a pending code for cam adjustment.

maz8062

2,295 posts

217 months

Thursday 6th June
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This is a known issue with the 276 engine. I believe it is the timing chain. Google is your friend.

Stussy

1,922 posts

66 months

M276 has secondary tensioner oil feed issues, when parked the pressure/oil drains back out and causes it to rattle for a few seconds until oil pressure returns.
There is a fix to fit non return check valves in the oil feed line. Its not a recall issue and MB won't fix it for free either.
If you google, a Xentry bulletin about it can be found, I contacted a main dealer about it and pointed them to the bulletin and they literally didn't want to know. They wouldn't even show any interest to sort it if I paid either!

In the bulletin it states no damage can be caused and its just a noise.
Mine has rattled for about 4 years now, I've asked various supposed Mercedes specialists and not a single one seemed to want the work, which seemed odd to me!