Oil filter housing leak
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'13 GLK350 4matic,'10 C207,'15 GLA250,'07 Honda Odyssey, '18 GLE 43, '24 EQS 580
Oil filter housing leak
I just noticed an oil leak on the oil filter housing. Not sure if it is on the oil cooler or housing to be honest but I know it is coming there as I had that before on the W204. I want to tackle this DYI and I want to get advice on the following:
1. Do I just replace the 2 gaskets or replaced the entire assembly? that is a $40 gasket kit or a $400 part.
2. Do I replace the thermostat while I am at it?
3. Do I replace the belt and the belt tensioner while I am it?
4. I am assuming it is best to flush the coolant as I think it still has the original coolant.
5. What else should I replace as preventive maintenance while I am tackling this job?
6. If you have done this job before can you post part numbers? Thinking of going to FCP Euro or ECS tuning. I noticed there are aftermarket parts available for the housing.Do I go original or Mercedes parts?
1. Do I just replace the 2 gaskets or replaced the entire assembly? that is a $40 gasket kit or a $400 part.
2. Do I replace the thermostat while I am at it?
3. Do I replace the belt and the belt tensioner while I am it?
4. I am assuming it is best to flush the coolant as I think it still has the original coolant.
5. What else should I replace as preventive maintenance while I am tackling this job?
6. If you have done this job before can you post part numbers? Thinking of going to FCP Euro or ECS tuning. I noticed there are aftermarket parts available for the housing.Do I go original or Mercedes parts?
Last edited by shotgun_banjo; Feb 22, 2025 at 12:47 PM.
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Joined: Aug 2004
Posts: 954
Likes: 245
E550 Coupe 2wd (2016)
You'd probably get some hits if you note what engine it has.
On my oil cooler, M278 engine, it would likely be a cam positioner leaking and you can replace just the O-ring on it/them if you want.
The way I locate difficult to find leaks is clean the area, then look for the leak to appear. If it makes too much of a mess and/or hard to see where it started then I'll stuff a clean rag in there. When you pull it out the oil should, hopefully, be focused on the leaky spot, and/or the spot on the rag should give it away.
If it's the oil filter housing gasket I'd only replace the gasket, no point in replacing the housing, unless damaged, which I doubt.
When I look for parts I generally look on several sites, like FCP, Pelican and misc others to see what the average part # is because sometimes they give the wrong #. Then MB will update #'s so you get to decipher if it's the correct #, old #, latest #?
The other parts are up to you. When my thermostat died last Dec I bought a bunch of misc parts to swap out while I was in there, just in case I needed to. When I got in there they all seemed fine so I only replaced the belt and coolant. And the stat, obviously. Many people would replace everything, but I don't have good luck with new parts. Since I had about a dozen new parts, the odds of all of them working fine and leak free is pretty low.
On my oil cooler, M278 engine, it would likely be a cam positioner leaking and you can replace just the O-ring on it/them if you want.
The way I locate difficult to find leaks is clean the area, then look for the leak to appear. If it makes too much of a mess and/or hard to see where it started then I'll stuff a clean rag in there. When you pull it out the oil should, hopefully, be focused on the leaky spot, and/or the spot on the rag should give it away.
If it's the oil filter housing gasket I'd only replace the gasket, no point in replacing the housing, unless damaged, which I doubt.
When I look for parts I generally look on several sites, like FCP, Pelican and misc others to see what the average part # is because sometimes they give the wrong #. Then MB will update #'s so you get to decipher if it's the correct #, old #, latest #?
The other parts are up to you. When my thermostat died last Dec I bought a bunch of misc parts to swap out while I was in there, just in case I needed to. When I got in there they all seemed fine so I only replaced the belt and coolant. And the stat, obviously. Many people would replace everything, but I don't have good luck with new parts. Since I had about a dozen new parts, the odds of all of them working fine and leak free is pretty low.
Senior Member
Joined: Jan 2017
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From: Orange County, CA
W222 S550e, C207 E550, W212 E350
I just had a leaking oil filter housing on my M278 E550 coupe.
It is a common problem for them to warp over time. Even if you do just new gaskets, it could still leak if warped... It is best to replace the housing and gasket together. My mechanic said that the thermostat breaks almost every time upon removal. So I had to get a new thermostat, coolant, and oil filter housing. Might as well replace the belt too. Its a cheap enough part. Good luck
It is a common problem for them to warp over time. Even if you do just new gaskets, it could still leak if warped... It is best to replace the housing and gasket together. My mechanic said that the thermostat breaks almost every time upon removal. So I had to get a new thermostat, coolant, and oil filter housing. Might as well replace the belt too. Its a cheap enough part. Good luck
Super Member
Joined: Aug 2004
Posts: 954
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E550 Coupe 2wd (2016)
The guy selling the expensive part said you need a new one? I also have an expensive part you need. Call now and get a second one for half price!
I'm teasing you, sorta... I would not believe that unless I saw it myself. Even if it were somehow warped so badly that it leaked, which I cannot imagine, I would simply sand it flat again.
I'm teasing you, sorta... I would not believe that unless I saw it myself. Even if it were somehow warped so badly that it leaked, which I cannot imagine, I would simply sand it flat again.
Thread Starter
MBWorld Fanatic!
Joined: Jun 2011
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'13 GLK350 4matic,'10 C207,'15 GLA250,'07 Honda Odyssey, '18 GLE 43, '24 EQS 580
The guy selling the expensive part said you need a new one? I also have an expensive part you need. Call now and get a second one for half price!
I'm teasing you, sorta... I would not believe that unless I saw it myself. Even if it were somehow warped so badly that it leaked, which I cannot imagine, I would simply sand it flat again.
I'm teasing you, sorta... I would not believe that unless I saw it myself. Even if it were somehow warped so badly that it leaked, which I cannot imagine, I would simply sand it flat again.
Super Member
Joined: Aug 2004
Posts: 954
Likes: 245
E550 Coupe 2wd (2016)
I spoze if you get one I'd buy a used one on ebay. I believe there are only two types that fit, with and without oil cooler lines. ebay junkyards are cool because they post lots of pix to a feel of what you're dealing with. Plus you could get a new plug for the relief valve since rumor has it they leak after xx years? Probably just an O-ring.
I have those gaskets on hand just in case, which I think were closer to the $10 range from AutohauzAZ? There are a variety of places. I think the belt was $10 too. Stat was $110? I believe a new stat could be pulled in n out all you want, but with time they break. They have three plastic tabs that look to me like a "fail after warranty" design. So if original I'd replace it. Mine lasted 9 years, which is why I know those prices. I replaced in Dec.
There's also the left turbo lines you may want to look into.
I have those gaskets on hand just in case, which I think were closer to the $10 range from AutohauzAZ? There are a variety of places. I think the belt was $10 too. Stat was $110? I believe a new stat could be pulled in n out all you want, but with time they break. They have three plastic tabs that look to me like a "fail after warranty" design. So if original I'd replace it. Mine lasted 9 years, which is why I know those prices. I replaced in Dec.
There's also the left turbo lines you may want to look into.
