Oil Cap Buildup ??

[svfetter]

Curious situation on my 2011 Expedition. I drive about 5 miles to work every day one way. After having fresh oil and filter installed before winter, when changing this spring, when I took off the oil cap it was full of a light tan whipped cream substance. Clearly a mixture of oil and moisture which is not burnt off on my short drive to work in the winter. Oil looked normal when drained and temp gauge gets to normal before I get to work. After changing oil this spring it has still been cool and after a week of driving I checked the cap and this light creamy coating had started to form in the cap again. Cleaned it all out.

Never had this on my previous Expedition driving the same trip every morning. Further, my wife drives her 95 Mustang even a shorter distance to a bus stop every day and no issue with her in all the years I have owned that car.

The new Expedition did not do this during the last summer. No Creamy buildup in the oil cap during the hotter months. I have owned nothing but Fords all my life and never seen anything like this. Any Ideas ??

 

[jimb726]

Just condensation underneath the cap. As a mechanic I used to see this all of the time. If the oil is clean with no indication of coolant in it, then its nothing more than condensation in the fill tube. Clean it out and you should be fine.

 

[svfetter]

I think I have come across a major cause in further discussion - and that is the 7 quart factor. That is a considerable amount of oil to heat up as has been pointed out pointed out. My earlier expedition only had 6 quarts. I believe this may be the main issue with a short drive. With that amount of oil and a short drive, it's just not enough to drive our the condensation you spoke of

Further - in commenting on the Temp gauge as you spoke of, it does come up slowly, but if Ford is employing the same design as my 2007 Mustang - Gauge is actually reading head temp and not coolant temp. In this case all fluids would be cooler than head and what gauge is showing.