Mayo in the expansion tank

Checked the expansion tank today before a run and found the water is mixed with creamy grey coloured mayo. 
The car is running great with no heating problems and the oil cap and dip stick are clear of any mayo but is this the sign of HGF.
Its a 2004 115 TF with 60k on the clock
Cheers 
Martin

 

When did you last check it?
Have you done many miles since?

Sadly sounds as if the head gasket has failed. My previous hg fails have shown similar signs, plus overpressure into the coolant causing rising coolant level on running.

Yes I think I knew it would be, just hoping someone would say " nothing to worry about just down to lack of use".  The fact that no mayo in the oil or heating probs and sniff test showing negative confused me.
 

The only other possibility is that it is from a previous gasket failure and it's been stuck in the coolant pipework somewhere. Have you done any work on the system recently?

Hi David
The cam belt and water pump were change end of April this year which was last done in  2015 . I have done less than 200 miles since April. I will flush the system a couple of times and see how it goes and may have the HG done regardless , always been a great believer in if it ain't broke don't fix it.
 

The Mayo saga
 I took for a run to the local motor factors yesterday to buy coolant flush and OAT by the time I got back all the mayo had gone.
I flushed and changed the coolant following David Aiketgate,s How to Guide anyway (it was that or shopping) went for a good run last night and just checked it again and all seems OK.
So maybe fingers crossed just condensation.

Thanks all
Martin