Benzo1999

It's nasty cold here in Chicago & our trusty winter buggy (99 ML430) is looking sick. After changing the oil last week I noticed some condensation sludge on the filler cap. You know...the creamy foam. I talked to my local wrench & he said a little is ok. I'm thinking any is too much (buildup can be a problem). The oil is fine ie: not milky. Exhaust is dry ie: no extra steam or burnt coolant. Everything checks out. My only thought is a posible breather could be loose.

Does anybody have any ideas??? I don't think it's a head gasket...

sosh

That is a known condition and completely normal. Caused by condensation when using the vehicle for short trips particularly in cold weather. Engine does not get up to operating temp. One longer trip at highway speeds and it will go away.

TECHNICIAN

+1

vettdvr

Correct. But be sure to check you engine temps to insure the engine is warming up and doesn't have a stuck thermostat. If you have cabin heat normal the thermostat is probably opening and once you drive the engine to heat it up it will clear up.

Interesting though My F150 was underwater in Katrina. I got to the truck 4 days after it flooded. The engine would not do a 360 turn by hand with plugs out due to rust in the cylinders. I drained the oil and oiled the cylinders and turned the engine by hand until it freed up, then spun it with the starter. I had only drained the water off the bottom of the oil but did not have fresh oil to use. The oil that contained the water was still in the engine. I started the engine and drove at highway speeds for 2000 miles then realized the oil had not been changed. All of the water had boiled away and the engine has now driven 25000 more miles with no issue. So you probably are in good shape once you drive your engine and heat it up.