Hello all. Last sunday I discovered a lot of oil in my coolant expansion tank mixed with the coolant fluid.
In the afternoon, the car left a lot of oil + coolant in the floor. When I opened the oil filler cap, I noticed a little bit of steam, and the expelled oil was obviously mixed with water, so I decided to tow it to a garage. The next morning, we found that the oil level had dropped about 1 liter from the day before.
Do you, guys, think that there is another possible cause for this appart from the obvious one (head gasket / cracked head or block) like a water pump seal or something?

Thanks!

1992 190E 2.3 (8 valve)

Your radiator cools two liquids .. engine coolant and transmission fluid so the radiator could also be the culprit.

Don't be so quick to point to the head gasket without looking to the radiator.

What color is the sludge in the expansion tank?

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-Paul-
'01 E430, Sport 72,000 mi
'98 C280, 126,500 mi

I think that my radiator (that is not oem), only cools the engine, and I have manual transmission. You meant the automatic transmission, didn't you?

Thanks!

Yes I assumed you had an auto transmission.

Oil in coolant almost certainly = blown head gasket.

Good Luck

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-Paul-
'01 E430, Sport 72,000 mi
'98 C280, 126,500 mi

welcome to the club. I have oil in my coolant tank, but no other signs of a blown head gasket- no overheating, no steam at the exhaust pipe and no water in the oil.
Just oil burning... what fun

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1993 320TE M104
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past:

1983 230E W123 M102
1994 E300D S124 OM606 (x2)
1967 250SE W108 M129
1972 280se 3.5 W108 M116
1980 280SE W116 M110
1980 350SE W116 M116
1992 300E W124 M103
1994 E280 W124 M104
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"music and women I cannot but give way to, whatever my business" -Pepys

chazola,

if you just have a few droplets of oil floating in the coolant tank things aren't bad, when the coolant looks like chocolate milk that is when it is time for action.

the car seems to have a mind of it's own- sometimes I'll go a week with just a thin blob in the corner of the tank, sometimes it's chocolate milk.
I'm selling it next month anyway so there's no point me shelling out for the head job now- I'm just gonna lower the selling price. The car is pretty much tip-top otherwise.

__________________
1993 320TE M104
---------------------------------------------------
past:

1983 230E W123 M102
1994 E300D S124 OM606 (x2)
1967 250SE W108 M129
1972 280se 3.5 W108 M116
1980 280SE W116 M110
1980 350SE W116 M116
1992 300E W124 M103
1994 E280 W124 M104
----------------------------------------------
"music and women I cannot but give way to, whatever my business" -Pepys

I too had small droplets of oil in my water/radiator overfill tank, but I couldn't find any other "tell tell" signs of a leaking head gasket. Needless to say I was extremely worried I had a leaking head gasket. As it turns out, after searching other post and forums, I discovered the oil in the water was a result of RedLine's Wetter Water aditive I was using to lower the cooling temp.

Are you using Redline Wetter Water?

After flushing the radiator with an oil removing mixture, and not adding the Wetter Water, I've never experienced the oil droplets in the radiator again!

Russell

__________________
Russell McMahon
Tulsa, OK
2001 CLK 320
1992 400se
1993 400e
2000 320ML

Well, first I noticed a kind of white "soap" in the expansion tank cap, but last sunday the water turned into chocolate, and after refilling the oil level, a few kilometers later, the car started to throw oil mixed with water through the oil filler cap. The oil level dropped a lot.

Is there any gasket in the water pump that can produce the same effect?

Thanks!

FWIW, when I saw oil in my expansion tank (this was shortly after a bout of overheating from a stuck thermostat), my indie said to take care of it sooner rather than later. Oil in the coolant deteriorates ALL the rubber hoses, adding to the cost of a head gasket replacement.

glenmore
1991 300CE
1990 LS400

rsmcmahon-

I'm not using water wetter but I did use some MMO to quiet a noisy lifter. I read later than this stuff can possibly dissolve gaskets and I'm wondering if this is true as my oil in coolant problem appeared soon after I used the MMO.

The weird thing is my expansion tank has old oil stuck to the inside top of it, and I'm wondering if this drips down when the tank gets hot.
Maybe I should try cleaning the tank out throroughly or get a new one and see what happens.

__________________
1993 320TE M104
---------------------------------------------------
past:

1983 230E W123 M102
1994 E300D S124 OM606 (x2)
1967 250SE W108 M129
1972 280se 3.5 W108 M116
1980 280SE W116 M110
1980 350SE W116 M116
1992 300E W124 M103
1994 E280 W124 M104
----------------------------------------------
"music and women I cannot but give way to, whatever my business" -Pepys

You've DEFINITLY got a blown head gasket. If the running engine is spraying water out of the oil fill cap, stop running the engine. It's time to fix it, not run it more and risk spinning bearings. That's what happens when the oil gets mixed with water.

Can you say lotsa $?

__________________
Norm in NJ
Next oil change at 230,000miles