The dreaded mayonnaise

[DeusMR2]

This morning after warming up the car, I opened the oil filler cap and saw a good dollop of mayonnaisey stuff, obviously some water has mixed with oil

Its at least 1-2mm thick and covers half the inside of the cap. (I had cleaned the inside of the cap in September so this layer has developed since then)

So does this mean my headgasket is on the way out? Is it a DIY job i.e. simply a matter of swapping it for the old one and tightening everything back down?

[JJ]

If your only doing short journeys, this scum can form in the cap, not a worry !!!

Perfectly natural for the internals to build a small bit of condensation this time of year.

It often forms around the internals where the oil pump meets the hot block, as the coolant / block reaches normal running temperature earlier that the oil pump / oil itself - the condensations formed as a result of the offset in temperature between this cooler oil running along side the hot block in other words.

Like your cold winter mornings, the windows will be prone ( non double glazed ) to condensate due to the warm air in the house.

[DeusMR2]

Thanks JJ, you've put my mind to rest . I do about 4 x 4mile trips a day in suburbs (poor car lol) so what you've said makes perfect sense

[ENSMR2]

JJ I do about 9 miles to work. 95% of the journey is dual carriage way so no stopping. What you reckon. Should I check for gunk or will the fact I open her up a bit more on the DC resolve that issue

[Hedgehog Dodger]

JJ I do about 9 miles to work. 95% of the journey is dual carriage way so no stopping. What you reckon. Should I check for gunk or will the fact I open her up a bit more on the DC resolve that issue

LOL, JJ the MAYO MAN!!!!!!

You will be fine fella, condensation as JJ has said

[ENSMR2]

The big dollops right! lol