Just purchased a 2003 Mercury Mountaineer with 4.6L V8. 42k miles. Engine and car beautifully detailed. I serviced the truck. Oil was dirty but no signs of water or foam. I did notice under the oil fill cap there was a small amount of a creamy foam. Any ideas what that could be from. I don't know how long the truck sat before I got it. Could it be from a PCV valve or maybe from when engine was detailed? Thanks in advance, Ray

 

It is just condensation.

 

My 2000 expy was doing that. Had me in a panic till I talked to a mechanic, he said the new engines make a lot of moisture and if you make a lot of short trips the engine doesn't get hot enough to let it evaporate. Talked to my wife and sure enough she had been making 2 or 3short trips a day between offices. She got a new job with a longer drive and the moisture went away.

 

and or maybe the thermostat may be stuck open or not letting the engine get up to temperature.

 

All good answers Guys. Thanks, I feel better. I'll keep my eye on it.

 

Jetdad, See my post in the Expy forum. Exact same issue and i have pics, so let me know if its similar to mine.

Similar discussion as here, may be nothing.... check oil, change thermostat, etc. etc. Like you, I hope its nothing...

https://www.ford-trucks.com/forums/8...er-in-oil.html

 

Thanks for the info KR1. I'm feeling better that it only might be condensention. Oil we drained was dirty but not foamy. We're not seeing any water dropplets on dip stick so a long run might clear everything up. Thanks again, Ray

 

no problem, I to have hope that mine is something simple and not the head gasket... Actually have my Haynes manual out now preparing for the worst case DIY repair...

I have not drained the oil yet, but the dip stick is clean.

 

Update:
Last week was 50 to 70deg in alabama, checked the cap, no stuff..
This morning, was 35deg, check the cap and was white goo with a few drops of water...

Ill take a little bit of white goo, vs head gasket..