jamie645

I went to add oil yesterday to my 2000 e320 wagon and this is what I saw on the cap and at the top of the filler neck.
I use Mobil 1 0w40 and it was changed less than 6000 miles ago.
Thanks in advance

Quadcammer

its an oil and water emulsion. In other words, its condensation.

I get it too during the winter. Occurs due to short trips in cold weather where the oil does not get to a hot enough temperature to burn off all the water in the oil, and then even when you do, when you park the car, the condensation will occur again.

Nothing to worry about.

Jon2007E63P30

I also agree, condensation, water oil mix.

I do not agree that it is "nothing" to worry about.

If your driving habits result in lots of short trips, then the water will never evaporate. Water in the oil is just not good. It gets in the way of the oil doing what it is supposed to do, lubricate. Check the dip stick and see what the oil looks like there. If it looks normal then you probably are fine. If it looks like your filler cap, even a little, you are due for a good long drive or an oil change.

Myself, I would pick a nice day and drive! Get the enginer hot for a couple of hours and the water will be gone.

Quadcammer

well, as im sure you realize, the condensation forms on the highest points of the engine, which is the oil fill cap on the 112/113. The dipstick is always fine. The other part of the problem is that the oil cap is about 3 inches off the surface of the valve cover, meaning it doesn't get as hot as the rest of the engine.

its always preferable to go for a long drive, but its not gonna harm anything.

harkgar

I disagree.

This looks like a mix of engine coolant and oil. The same happening to me with my 1974 Fiat 124 Sport. I do not know the exact cause of this but you better have this looked at. The stuff is creamy and looks like a Starbucks latte.

dgiturbo

I had the same thing on my wife's 2001 E320 Wagon after a short drive. The first time I saw it I freaked and swore it was a head gasket gone bad. Funny thing is the dipstick looked normal. It was during the middle of winter. Took a chance, and drove to a nearby gas station to add the oil the light said it needed, and could find no issues. Car idled and drove perfect. That was 3 years and 40,000K mls ago, and during winter is the only time I see it. If there is no engine missing or coolant loss, drive on and be happy.

Quadcammer

although thats what it looks like, this is a common situation on these motors.

it will go away during the warmer months.

jamie645

That was my fear. I thought maybe I had blown a head gasket.
I actually took that picture just after a two hour drive but everything has checked out fine.

Thanks to all

Quadcammer

if you're ever worried about it being coolant, do a simple test.

take the glob of "milkshake" and put it in an old frying pan.

When it starts to boil, it will seperate and you will see that its only water.

AsianML

I have the same thing on my oil cap, and only on the oil cap. I've done quite a bit of driving here and there this winter where the engine was not able to reach operating temperatures, so I'm not surprised.

n42w88

To anyone who's worried when they see this milkshake on the underside of the oil filler cap, you might want to remember that you use the dipstick to check not only the quantity of oil but also its condition. If the oil on the filler cap looks like milkshake, it just means the weather is cold.

To put your mind at ease, pull out the dipstick and look at the oil that's actually in the engine. If the oil on the dipstick looks like milkshake, you've got water in the oil and that's very bad - "don't start the car" bad. Chances are good that you'll never see milkshake in the crankcase.

We see this stuff on our oil filler caps all the time in the colder climates and it is nothing to worry about. It is a lot more common now that it's become engineering fashion to put the oil filler cap way up high where it doesn't get warm enough to drive out the moisture. Don't bother wiping it out of the cap with a rag - it will just come back next time you drive the car in cold weather.

harkgar

I agree with your dipstick check method.

However, Toronto winters are very cold, colder than New York most of the time and I have not seen anything like that photo over the 20 odd years I have been driving MB (one W126, one W201 and the latest W211).

No harm being careful.