Thanks for your replies, DCF & Supradupe.

The weather in the Northeast has been like a roller-coaster. We had a warm January and it did get real cold in the teens last February for almost 3 weeks straight. Yes, I had the plugs replaced about 14 months ago using Bosch Platinum-4's, 2 plugs for each cylinder. The MAF is about 2 years old and may need cleaning or replacement soon. Are the Bosch Platinum-4's considered stock plugs?

The dipstick has no sign of frothy oil mixture, just at the underside of the oil cap. Also, there is no sign of oil contamination on the coolant reservoir as well. You could be right, this may be normal but I am just being cautious I may destroy my engine if there is a leaky head gasket problem. I will try to take picture of the oil cap's underside and try to add it to my post.

First thing I do when I get home is pull out the code(s), replace the oil & filter, clean or replace the MAF, go for a new thermostat and fresh coolant while I'm on it. See what happens from here.

I read that a bad or clogged EGR valve may also cause similar problem. Is this true? Also from a similar posting, they mentioned that the upper radiator hose may get hard fast during engine warm up if the head gasket is leaky as the engine pressure goes to the cooling system. Can you concur on this as well? Any other suggestions or diagnostics measures that can be perform to pinpoint the cause of this frothy oil mixture?

Thanks, and appreciate all the assistance you both are providing. This forum is GREAT.

__________________
Josemin


88 MB 300E
88 MB 560SEL
99 MB ML 430