substance in cap

dvortt · Post by **dvortt** » 23 Mar 2005, 20:39

Hi to anyone out there , could i get some opinion on the creamy residude that built up in the oil filler cap , for the weekend i plan to probably do about 500miles, i thought to check n fill the oil, then noticed a build up of creamy white what i,ve thought to be probably oil water mixture , as the dippstick showed no trace should this be a worry. The cap seal, s seems good though, cuold this be a sign of something going on a bit worse cause its a bit thick. Thanks for any reply ..

mezuk04 · Post by **mezuk04** » 23 Mar 2005, 20:43

Isnt this something to do with the head gasket, my mates Fessa got the same, like mayo, and he had to have a new gasket, he drived so slowly he managed to keep it creamy for months without knowing.
Regards

dvortt · Post by **dvortt** » 23 Mar 2005, 20:46

if it is or not should this show when i check the dipstick as well....thanks

bxbodger · Post by **bxbodger** » 23 Mar 2005, 20:48

You don't say what car it is, but its probably "mayonnaise" not the edible sandwich variety, though.....but nothing to worry about.
Do you do a lot of short journeys and cold starts, if so, its nothing to worry about, just condensation mixing with the oil as the engine doesn't have time to get hot enough to evapourate it off. You may have a thermostat thats stuck open or missing, though, not allowing the motor to get hot.
A 500 mile journey will probably make it vanish.
Some engines are more prone to it than others, particularly with long metal oil filler necks, like the old rear sloping gears in sump pug 1400.

jeremy · Post by **jeremy** » 23 Mar 2005, 20:49

You don't say what car/engine, where you are, when the oil was last changed, what use the car gets etc.
Yes sounds like mayonnaise (oil/water emulsion) and some engines in some climates are prone. can just happen, can happen when the car never really warms up - or - it can happen if the head gasket fails, and it can form in the rocker cover. It can be caused by a blocked breatehr system - some have a steel mesh in the filler cap that clogs after a while.
Risk - ideally find problem, cure it, change oil and remove contamination.
jeremy

dvortt · Post by **dvortt** » 23 Mar 2005, 20:59

yeah it,s a m reg Xantia 105+ on mileage , this made me think of the h/gask , but you,re right about alot of short cold starts. Thermostat ? what not letting the motor engine get hot. Thanks for the imfo , maybe should be alright..

dvortt · Post by **dvortt** » 23 Mar 2005, 21:23

Just read a previous thead from a simalar situation, found it most useful and thank you,s for the reply,