Head gasket gone or just condensation

[adamgerken]

Morning, I am the owner of a 53 plate 1.0 corsa and have recently found some yellowy gunk around the oil cap, and am worried at whether my head gasket has gone or if it is just condensation. I do a lot of short journeys and have read that can be why the gunk is there, but also there is a substance that looks like that on the coolant cap. Would you think this is a big issue like head gasket or not a problem at all?

[steveo3002]

wouldnt worry too much...does the coolant level drop that would be more of a sign

[adamgerken]

Nope, haven't topped it up recently and is still at the mark, so sounds promising! Thanks 🤣

[jas xjr]

Have a look at your dipstick.there should not be any mayo on that.
Many years ago the headgasket went on my transit. The mayo was everywhere

[adamgerken]

Nope, no mayo on the dipstick but a friend told me that the water and oil would separate with the water depositing at the top, so you wouldn't see the gunk on the dipstick, but if that is not true then that also sounds good!

[E-bmw]

No, wrong.

As above a little on the cap is not a big deal in lieu of many short journeys, it is condensation mixing with the oil left around the cap.

This isn't good for a car long-term though, a good run every now & then will help get rid of it if that is all it is.

When/if you see water levels change or "mayonnaise" on the dip-stick that is different.

[jas xjr]

Maybe mine was an extreme case. Good luck with yours

[steveo3002]

if the failed headgasket is causing mayo its because coolant and oil are mixing...the coolant tank level would drop

if the coolant tank remains full then its condensation and oil mixing , collecting in the top corners and filler cap and will go away in warmer weather or a decent run when the oil remains hot enough to burn off the moisture

[GreenV8S]

adamgerken said:

also there is a substance that looks like that on the coolant cap.

That's the only part that would concern me. I suggest you wipe it off and see whether you can identify it, and whether it comes back.