M271 Exhaust Cam Timing

[adamofalltrades]

Hi all,

I am in the process of replacing the timing chain on my 2008 C Class with the 271.9 engine.

I have the necessary locking tools, however I am having an issue where the exhaust cam markings do not line up. The intake sits perfectly on the mark, however the exhaust is less than one tooth out. If I move the exhaust adjuster (also new) by one tooth, it moves the marking too much, and I am having a timing error code come up. I have attached pictures of the markings:

Any assistance would be appreciated, not sure why this issue is coming up.

Exhaust cam:


Intake cam:

 

[Petrol Pete]

Hello and welcome . Where did you get the new parts from ?

 

[Petrol Pete]

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You have probably watched enough of these videos , but here's one more . You are replacing the guides and tensioners as well ?

 

[W1ghty]

Did the engine have problems before the new parts ? Just wondering if there has been engine valve damage by chain stretch, chain jumping on the cams ….before the new parts .

 

[adamofalltrades]

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You have probably watched enough of these videos , but here's one more . You are replacing the guides and tensioners as well ?

Yep all parts replaced. It is a kit sourced from eBay

 

[adamofalltrades]

Did the engine have problems before the new parts ? Just wondering if there has been engine valve damage by chain stretch, chain jumping on the cams ….before the new parts .

Yes in fact the chain had jumped before this by one tooth on the exhaust cam. I put an inspection camera down the spark plug holes but couldn’t see any bent valves.

 

[W1ghty]

Yes in fact the chain had jumped before this by one tooth on the exhaust cam. I put an inspection camera down the spark plug holes but couldn’t see any bent valves.

I just wondered if that was the cause of the problem . But I have very little knowledge of what it could be .
Hopefully one of the resident experts will be able to help soon .

 

[Petrol Pete]

OP , what I meant by 'where did you get the parts from' I meant the supplier . I too have just bought parts for my car from Ebay ... but it was from Mercedes Benz of Newcastle who happen to have an Ebay shop = genuine MB parts.

 

[adamofalltrades]

OP , what I meant by 'where did you get the parts from' I meant the supplier . I too have just bought parts for my car from Ebay ... but it was from Mercedes Benz of Newcastle who happen to have an Ebay shop = genuine MB part

Just a generic chinese set available from retailers on eBay. The tolerances are acceptable, but as always, time will tell.

As it happens, I managed to retime and adjust everything, and now the engine runs without any issues at all. No timing error codes and sound like a normal petrol engine. My timing tools had a bit too much slack on the exhaust side, and required a lot of manual fiddling to get correct.