55k oil in coolant reservoir problem
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2004 e55 amg
55k oil in coolant reservoir problem
Hey new to the group, wondering if I can get some input on an issue I’ve recently had. I own a 2004 e55 I woke up and checked my fluids, to find out my coolant reservoir had a decent amount of oil in it. I was very concerned I’ve been searching all over the forums and theirs lots of answers but not much for the m113k. I’ve checked the oil filter housing, but beforeI say the worst I’m wondering if anyone else has had this issue before or has any advice thankyou!
Last edited by maxp_55; Mar 31, 2023 at 11:50 PM. Reason: Editing the title
MBWorld Fanatic!
Joined: Jun 2013
Posts: 1,517
Likes: 95
From: NZ
2004 E55 AMG, 2006 CLS63, 2004 ML55, 2014 E350 sport
Could be anything from headgasket (unusual on these unless someones done something silly with the tuning or something) or the o rings in the front cover or radiator failure and mixing transfluid.
So theres a chance it may not be a serious issue but only way to know is start investigating.
Headgasket should be pretty obvious in most cases as it will likely be bubbling in the reservoir with it running (but also maybe not).
If its just the timing cover O rings in the front cover you can drop the oil pan and probably see the coolant coming down from where the O rings are located (water pump feeds into block I think). This is a rare failure too but these cars are aging now so probably will get more common.
If it does end up being the O rings make sure you do them all including oil pump pickup for the updated versions and replace timing chain guides etc while your there may need to check rod bearings too while its open and decide properly from there if you need to pull the motor and go over it all properly.
So if your not seeing water in the oil too then you are probably up chit creek. Either way you need to get it diagnosed accurately with the right gear.
So theres a chance it may not be a serious issue but only way to know is start investigating.
Headgasket should be pretty obvious in most cases as it will likely be bubbling in the reservoir with it running (but also maybe not).
If its just the timing cover O rings in the front cover you can drop the oil pan and probably see the coolant coming down from where the O rings are located (water pump feeds into block I think). This is a rare failure too but these cars are aging now so probably will get more common.
If it does end up being the O rings make sure you do them all including oil pump pickup for the updated versions and replace timing chain guides etc while your there may need to check rod bearings too while its open and decide properly from there if you need to pull the motor and go over it all properly.
So if your not seeing water in the oil too then you are probably up chit creek. Either way you need to get it diagnosed accurately with the right gear.
Last edited by austingtir; Apr 1, 2023 at 01:58 AM.
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Joined: Sep 2018
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2017 GLE350 4MATIC
Any work done on the car lately?
Run the standard protocol for head gasket diagnosis:
- steam or sweet smell from tailpipe?
- rough idle?
- check engine light?
- external leaks on engine block?
- chocolate milkshake/cappuccino under oil fill cap?
- spark plugs washed clean?
- top of piston crown washed clean?
- bubbles in coolant reservoir while idling?
- gradual loss of coolant?
- drain the oil and see what comes out
Other possibility is oil cooler failure. I don’t know how this engine accomplishes oil cooling but I recall on this site other engines have had oil in the coolant from a failed oil cooler.
Run the standard protocol for head gasket diagnosis:
- steam or sweet smell from tailpipe?
- rough idle?
- check engine light?
- external leaks on engine block?
- chocolate milkshake/cappuccino under oil fill cap?
- spark plugs washed clean?
- top of piston crown washed clean?
- bubbles in coolant reservoir while idling?
- gradual loss of coolant?
- drain the oil and see what comes out
Other possibility is oil cooler failure. I don’t know how this engine accomplishes oil cooling but I recall on this site other engines have had oil in the coolant from a failed oil cooler.
