Mercedes-Benz Forum banner

Sludge and Leak

3K views 20 replies 12 participants last post by  art_arev 
#1 · (Edited)
Hi guys,

Did some maintenance today and found yellow/brown/goldish sludge on the oil filler cap. It was also around the top of the inlet.

What is this? Why is it appearing now and not before? My last oil change was maybe 2000 miles ago. I have not done any seafoaming for about 2 years is it time? Could this be related to to the leak that depicted below?





Any guesses to where this leak could come from? I changed the power steering fluid reservoir along with its o ring about 18 months ago. It seems very hard to pinput the source. It appears the serpentine belt slung it all around the front of the engine. There is even quite a bit on the alternator.
What would be a good method to pinpoint the source of the leak. How can i tell if the leaking fluid is motor oil or PS fluid?







as always your help is appreciated.
 
See less See more
7
#2 · (Edited)

Attachments

#4 ·
thank you for the help guys.

I gave the engine compartment a good clean today and slightly tightened the bolts on the oil pressure testing port. I will check for oil after the next drive.

i have cleared the vent, which even with the video and diagrams was a PITA to find so for other users heres are some reference pictures:



 
#9 ·
it is the first time that my florida car is exposed to temperatures below freezing. Good point, I did not think of that.

would a damaged thermostat not throw a code?

I do have a remote start so I usually let her warm up for at least 5-10 minutes on when its cold out. It is my impression that letting it warm up under no load conditions reduces engine wear. But i could be wrong.


and out of curiosity what is the reason for the vent hole? i mean what evaporates in the oil? or what substance/gas does it need to vent.
 
#10 ·
Some say the "mayonaise" is normal during cold weather.....
But logicaly it doesnt make any sense.....You are using high quality syntetic oil in a high quality piece of equipment. Some have the mayo, but there is no way that this is normal & acceptable, in any weather.....
With you vents cleared try it out & give us an update......
You would have known if your thermostat is dodgy.......
 
#11 ·
It can be normal. Remember the engine case is not airtight. Moisture is building up all of the time if you are in a humid environment. It is removed not by the oil but from running the engine for an extended time at normal operating temperature.

Now, water can also get in from the cooling system. So it doesn't hurt to check for leaks. But it is a normal event in cold, humid weather when not driven often enough.
 
#14 ·
so a couple of days ago i rechecked and there was even more sludge than before!

So turns out there are two ventilation holes! who would have thunk it ;)
It was not one of my brightest moments...but if anybody has the same problem make sure TO CLEAR BOTH HOLES! one on each side...
 
#16 ·
The 'mayo' is normal in any engine that has seen relatively short heat cycles in cold weather. The oil has not had a chance to flash off collected water vapor. A few long drives should clear that up.

Its not a head gasket, assuming the oil on the dipstick looks normal. Besides, there are no other HG symptoms mentioned, so lets not jump to expensive conclusions.
 
#17 ·
I would guess that being in Arkansas the much lower temps they have had for for much longer durations on decades has contributed to this problem and made it look a lot worse than it is. Livening up north here 'eh we are used to it in the winter as the truck gets more short trip driving as my wife and I do not ride our bikes to local things at all in the winter. Once spring hits and it stays above 55º I never see the "peanut butter" on the cap or filler neck.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top