OM651 CHAIN TENSIONER
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Junior Member
Joined: May 2020
Posts: 52
Likes: 13
W212
OM651 CHAIN TENSIONER
so the om651 engine is know for begging to develop a chain rattle for a few seconds right after starting the car, this usually happens after a couple hundred thousand km on the car. Normally, after replacing the tensioner with the new upgraded one (4 holes instead of 2 for better oil flow), the rattle is gone.
i have seen multiple people recommend this and it seemed to have solved their issue. sure, the chain could also be stretched, but wouldn't the rattle be present at all times then? not just the start.
that's my question, really..
i had this chain rattle for like 2-3 seconds first time after starting the engine, could barely hear it, but it was there.
i ordered new chain tensioner from INA, replaced it according to WIS instructions.
buuut the noise is still there, and it seems like its actually a bit worse than before.
i also checked the timing, everything is as it should, so i'm thinking if the timing is ok, then the chain should not be stretched, right?
so then why the noise still?
i compared the old tensioner with the new one, but i feel like the older one had more 'springiness' in it, i fell like it was harder to push then the new one. what? should the new one be harder to push in, have a stronger spring?
and i repeat, the noise is there only at almost every engine start, for 4-5 seconds now. after that no noise, no rattle.
i have seen multiple people recommend this and it seemed to have solved their issue. sure, the chain could also be stretched, but wouldn't the rattle be present at all times then? not just the start.
that's my question, really..
i had this chain rattle for like 2-3 seconds first time after starting the engine, could barely hear it, but it was there.
i ordered new chain tensioner from INA, replaced it according to WIS instructions.
buuut the noise is still there, and it seems like its actually a bit worse than before.
i also checked the timing, everything is as it should, so i'm thinking if the timing is ok, then the chain should not be stretched, right?
so then why the noise still?
i compared the old tensioner with the new one, but i feel like the older one had more 'springiness' in it, i fell like it was harder to push then the new one. what? should the new one be harder to push in, have a stronger spring?
and i repeat, the noise is there only at almost every engine start, for 4-5 seconds now. after that no noise, no rattle.
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
VVT Gear rattle
so the om651 engine is know for begging to develop a chain rattle for a few seconds right after starting the car, this usually happens after a couple hundred thousand km on the car. Normally, after replacing the tensioner with the new upgraded one (4 holes instead of 2 for better oil flow), the rattle is gone.
i have seen multiple people recommend this and it seemed to have solved their issue. sure, the chain could also be stretched, but wouldn't the rattle be present at all times then? not just the start.
that's my question, really..
i had this chain rattle for like 2-3 seconds first time after starting the engine, could barely hear it, but it was there.
i ordered new chain tensioner from INA, replaced it according to WIS instructions.
buuut the noise is still there, and it seems like its actually a bit worse than before.
i also checked the timing, everything is as it should, so i'm thinking if the timing is ok, then the chain should not be stretched, right?
so then why the noise still?
i compared the old tensioner with the new one, but i feel like the older one had more 'springiness' in it, i fell like it was harder to push then the new one. what? should the new one be harder to push in, have a stronger spring?
and i repeat, the noise is there only at almost every engine start, for 4-5 seconds now. after that no noise, no rattle.
i have seen multiple people recommend this and it seemed to have solved their issue. sure, the chain could also be stretched, but wouldn't the rattle be present at all times then? not just the start.
that's my question, really..
i had this chain rattle for like 2-3 seconds first time after starting the engine, could barely hear it, but it was there.
i ordered new chain tensioner from INA, replaced it according to WIS instructions.
buuut the noise is still there, and it seems like its actually a bit worse than before.
i also checked the timing, everything is as it should, so i'm thinking if the timing is ok, then the chain should not be stretched, right?
so then why the noise still?
i compared the old tensioner with the new one, but i feel like the older one had more 'springiness' in it, i fell like it was harder to push then the new one. what? should the new one be harder to push in, have a stronger spring?
and i repeat, the noise is there only at almost every engine start, for 4-5 seconds now. after that no noise, no rattle.
You new tensioner failed to quiet startup rattle. You will need to inspect/replace VVT gears that are worned out by limited oil pressure.
Don't worry about chain or chain guides - Nothing to do with standard rattle.
In addition your engine will benefit better oil changed more often. Old oil has extra-poor viscosity ie. "low oil pressure"...
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Member
Joined: Oct 2014
Posts: 222
Likes: 2
From: Melbourne Australia
MY06 E55
Doing a search, as my GLC250CDI, ( same engine ) has the same issue.
Start it when cold, bag of bolts , till oil pressure comes up ( 5 seconds or so )
When warm, 1 second or so.
I bought the timing chain kit, which had tensioner, chain, and 2 top sprockets. and guides.
My plan was to do tensioner first. or try and feed the chain in while tensioner is out.
Any suggestions ??
How difficult was it to do tensioner ?
i do add Lucas oil stabilizer, each oil change, but doesn't seem to help.
Start it when cold, bag of bolts , till oil pressure comes up ( 5 seconds or so )
When warm, 1 second or so.
I bought the timing chain kit, which had tensioner, chain, and 2 top sprockets. and guides.
My plan was to do tensioner first. or try and feed the chain in while tensioner is out.
Any suggestions ??
How difficult was it to do tensioner ?
i do add Lucas oil stabilizer, each oil change, but doesn't seem to help.
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Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
651 RATTLING FIXES
Doing a search, as my GLC250CDI, ( same engine ) has the same issue.
Start it when cold, bag of bolts , till oil pressure comes up ( 5 seconds or so )
When warm, 1 second or so.
I bought the timing chain kit, which had tensioner, chain, and 2 top sprockets. and guides.
My plan was to do tensioner first. or try and feed the chain in while tensioner is out.
Any suggestions ??
How difficult was it to do tensioner ?
i do add Lucas oil stabilizer, each oil change, but doesn't seem to help.
Start it when cold, bag of bolts , till oil pressure comes up ( 5 seconds or so )
When warm, 1 second or so.
I bought the timing chain kit, which had tensioner, chain, and 2 top sprockets. and guides.
My plan was to do tensioner first. or try and feed the chain in while tensioner is out.
Any suggestions ??
How difficult was it to do tensioner ?
i do add Lucas oil stabilizer, each oil change, but doesn't seem to help.
Inspect & replace the failed cam. phaser + tensioner.
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Member
Joined: Oct 2014
Posts: 222
Likes: 2
From: Melbourne Australia
MY06 E55
Thread Starter
Junior Member
Joined: May 2020
Posts: 52
Likes: 13
W212
It’s really not that complicated to replace the tensioner.
Turn engine to OT, this way you will be able to put back the tensioner easily.
You don’t really need the special adapter for turning the engine, you can turn it using just one e16 (I think, or e14) socket. (Or maybe you can turn it by hand?)
Im not sure about the space in the engine bay for your GLC, maybe you have more space.. but for me, I could not use my 1/2 torque wrench to torque it down from above the engine. Even to take out the tensioner it was a bit tricky as space was limited. Long socket extension was too long, short one was too short. In the end I was able to torque it down from below, with crazy extension and joint adapter., and another persons holding steady the adapters from above the engine bay.
so I would suggest trying with a 3/8 wrench, maybe you can reach the tensioner more easily from above.
Turn engine to OT, this way you will be able to put back the tensioner easily.
You don’t really need the special adapter for turning the engine, you can turn it using just one e16 (I think, or e14) socket. (Or maybe you can turn it by hand?)
Im not sure about the space in the engine bay for your GLC, maybe you have more space.. but for me, I could not use my 1/2 torque wrench to torque it down from above the engine. Even to take out the tensioner it was a bit tricky as space was limited. Long socket extension was too long, short one was too short. In the end I was able to torque it down from below, with crazy extension and joint adapter., and another persons holding steady the adapters from above the engine bay.
so I would suggest trying with a 3/8 wrench, maybe you can reach the tensioner more easily from above.
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
I bought the timing chain kit, which had tensioner, chain, and 2 top sprockets. and guides.
Everything is included in your kit.
