When to replace timing chain
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Joined: Apr 2019
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2012 Mercedes C250 1.8L turbo
When to replace timing chain
My wife's 2012 Mercedes C250 coupe with the 1.8L turbo (M271) engine with 160,000kms has had a rattle only at cold startup for a while now. At one point it was really hard to start so I replaced the camshaft adjusters and timing chain tensioner which resolved the startup issue. But it still rattles at startup and throws some of the codes related to this issue. Other than that the car still runs great.
My question is how long should I wait to replace the timing chain? It feels tight when I remove the valve cover and try to move/wiggle it. And there is no rattles at all after the car is started and it runs fine. Or should I try an OEM tensioner that may stop/reduce the bleed down of oil which from what I read is what causes the rattle at startup issue until the oil pressure builds.
Also if I go the timing chain replacement, what's the best quality one to use? I don't want to do that job more than one time.
Richard
My question is how long should I wait to replace the timing chain? It feels tight when I remove the valve cover and try to move/wiggle it. And there is no rattles at all after the car is started and it runs fine. Or should I try an OEM tensioner that may stop/reduce the bleed down of oil which from what I read is what causes the rattle at startup issue until the oil pressure builds.
Also if I go the timing chain replacement, what's the best quality one to use? I don't want to do that job more than one time.
Richard
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Joined: Sep 2020
Posts: 90
Likes: 22
2015 C250 Coupe M271.860
My wife's 2012 Mercedes C250 coupe with the 1.8L turbo (M271) engine with 160,000kms has had a rattle only at cold startup for a while now. At one point it was really hard to start so I replaced the camshaft adjusters and timing chain tensioner which resolved the startup issue. But it still rattles at startup and throws some of the codes related to this issue. Other than that the car still runs great.
My question is how long should I wait to replace the timing chain? It feels tight when I remove the valve cover and try to move/wiggle it. And there is no rattles at all after the car is started and it runs fine. Or should I try an OEM tensioner that may stop/reduce the bleed down of oil which from what I read is what causes the rattle at startup issue until the oil pressure builds.
Also if I go the timing chain replacement, what's the best quality one to use? I don't want to do that job more than one time.
My question is how long should I wait to replace the timing chain? It feels tight when I remove the valve cover and try to move/wiggle it. And there is no rattles at all after the car is started and it runs fine. Or should I try an OEM tensioner that may stop/reduce the bleed down of oil which from what I read is what causes the rattle at startup issue until the oil pressure builds.
Also if I go the timing chain replacement, what's the best quality one to use? I don't want to do that job more than one time.
That’s odd that you still had a rattle after your replaced camshaft adjusters and the timing
tensioner.
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Joined: Sep 2020
Posts: 90
Likes: 22
2015 C250 Coupe M271.860
Yeah the cause could be a lot of things. There's a lot of info out there on forums mostly about the kompressor M271 timing set. (could be sprockets, guides, tensioner, worn chain etc). But this one seemed interesting - on a W204 M271 they got a rattle after installing Mercedes brand tensioner. https://www.benzworld.org/threads/m2...ioner.3109155/ But who knows they could have messed up something else during the install.
Not sure I agree with that post that cold start rattle is normal. Maybe check with a local merc specialist.
Not sure I agree with that post that cold start rattle is normal. Maybe check with a local merc specialist.
