Mustard in the dipstick tube

[Alpine]

Checking the oil and found like yellow mustard looking stuff on the dipstick.

Is this a sign of a failing head gasket? I've not had a failed head gasket before so not too sure what to look for.

The car does not get that much use, maybe once or twice a week on shortish journeys, so is it more likely condensation?

Car has done 114k miles. Cheers

[Phaeton]

Originally Posted by Alpine

The car does not get that much use, maybe once or twice a week on shortish journeys, so is it more likely condensation?

In this weather yes, do you have the opportunity to take it on a good run, ideal a 10 mile M or dual carriageway A where you can sit at 60+ for 10 minutes? Then check it once it's cooled

[iain cooper]

Originally Posted by Phaeton

In this weather yes, do you have the opportunity to take it on a good run, ideal a 10 mile M or dual carriageway A where you can sit at 60+ for 10 minutes? Then check it once it's cooled

I would agree.

Iain

[SteveSarre]

as above .... and might as well confirm that the temperature gauge rises to the correct level (3 oclock) when it is warmed up (within 10 minutes) , and stays there when cruising at 60mph . If not, suspect the thermostat.

Steve

[stuarts]

Very likely to be condensation, i had an 850 that suffered this and ended up getting the engine up to temperature then running it with the filler cap removed to let the steam escape. You will need to cover the filler neck with a rag or things will get messy.

[ITSv40]

Condensation due to short journeys - nothing to worry about. The dipstick tube is in an exposed position so will not get warm on a short journey. The time to worry is if mayo appears under the oil filler cap.

[Alpine]

Many thanks for that all, phew. I'll give it a good run.

[DaveNP]

+1 it's fairly common on these cars/engines. As said the dipstick tube is out front of the engine and getting cold so the vapours out of the sump go up the tube and condense.
Check how good the rubber O ring is at the top of the dipstick, often they go hard so don't give a good seal which allows more vapours to go up the tube and condense. My car was quite bad for the mayo on the dipstick, the red top of the stick had been broken in the past and glued back together which ruined the seal of the O ring, I changed the dipstick and tube and haven't had a problem since. The new dipstick has two O rings and needs a new tube to go with it but it's not ridiculously expensive.