Fixing Oil Leak
Thread Starter
Junior Member
Joined: Jan 2020
Posts: 53
Likes: 9
2012 E550 4MATIC
Fixing Oil Leak
Hi all,
I am trying to fix my oil leak, as it seems to be a common problem with all M278 engines. All my research leads to having to change out the timing covers on both sides. What I want to know is, is it only the timing covers that need to be changes or do I need to replace the camshaft adjuster magnets as well? Can I reuse the bolts or are they one time use? Do I need to use a certain paste for sealing the parts?
Any info on swapping these out will help.
Also on a separate post I have been told about the oil cooler frame and seal. Are these issues related? And are these something I should swap as well?
Thanks.
I am trying to fix my oil leak, as it seems to be a common problem with all M278 engines. All my research leads to having to change out the timing covers on both sides. What I want to know is, is it only the timing covers that need to be changes or do I need to replace the camshaft adjuster magnets as well? Can I reuse the bolts or are they one time use? Do I need to use a certain paste for sealing the parts?
Any info on swapping these out will help.
Also on a separate post I have been told about the oil cooler frame and seal. Are these issues related? And are these something I should swap as well?
Thanks.
Super Member
Joined: Mar 2024
Posts: 618
Likes: 241
From: Chicago
19 GLA45, 86 560SL, former: 14 E550 4Matic, 09 E350 4Matic, 83 240D manual, 78 450SLC, 81 500SLC
Find the exact source of the leaks. It could be your cam adjusters only, or it could be the front camshaft covers, or both. The covers don't need to be replaced, they just need to be removed, cleaned, and resealed. There are some "while you're in theres" with that job...
I would not re-use any of those aluminum bolts.
I would not re-use any of those aluminum bolts.
Senior Member
Joined: Mar 2018
Posts: 485
Likes: 153
From: KY
2015 E63S Sedan, 2014 E550 coupe
Do take note that some (or all?) of those timing cover plates are made out of Magnesium and therefore only certain cleaning agents and techniques should be utilized.
I used and recommend the MB sealant. Study the application pattern note from WIS as well, to avoid making a mess or insufficiently sealing plates. Don’t overtighten bolts
I used and recommend the MB sealant. Study the application pattern note from WIS as well, to avoid making a mess or insufficiently sealing plates. Don’t overtighten bolts
