creamy gunk under oil filler cap? - shoei
What is this gunk under my filler cap?
creamy gunk under oil filler cap? - Kev1baby
Cylinder Head Gasket my friend
creamy gunk under oil filler cap? - smokie
Not necessarily. It's emulsified oil, caused by being mixed with water from somewhere, which could be condensation, head gasket or a few other things which better men than me can suggest.

What car type and are you losing coolant are usually the first questions.
creamy gunk under oil filler cap? - shoei
It is a 7 month old VW Golf 9,000 miles never used for short journeys, always more than 10 miles.
creamy gunk under oil filler cap? - Tony44
Straight back to the VW stealer in the morning then ;-)

Tony
creamy gunk under oil filler cap? - womble
Have you noticed any loss of coolant with this build up of gunk? My Polo does the same thing without losing any coolant. Although my journey to work is about 10 miles I have noticed this problem is much worse in the winter. I think with cold mornings the top of the engine just does not warm up as much with the really cold airflow around it.
creamy gunk under oil filler cap? - Toad, of_Toad_Hall.
Assuming it's not losing water and not overheating this has to be condensation due to cold starts.

It does seem a little odd that this should still happen despite longish journeys but I've seen a fiesta with mayo under the filler after 120 miles and 2 hours driving.

Relax. At this age it's just not going to be a problem.

Underlines the importance of regular oil changes though.
 

Value my car