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Alright,

I have been noticing a foamy build up on the underside of my oil cap over the past month, have cleaned it away and it seems to re form quite quickly, their is a small amount of water present (a few dops in the foam) as well. This was pointing towards a bit of a head gasket issue i thought, going out to buy some repair to extended it as long as possible. However intrestingly today i was checking the air filter and the same browny foam is present in the air filter??? It seems to be forming on a device (not actually to sure what it is) next to the carby intake, again their are traces of water in this oily foamy residue. So now to be honest i am stuck...what the hell is it? and why is it in my air filter as well as my oil cap? The car is a 1988 L series, EA82 stock standard havent even been near a water crossing..help..any ideas are welcome

usually if theres a white/browny foamy crap kidna substance it means 2 things
1 - head gasket check the colour of ur oil
2 - moisture is forming inside the engine never seen or heard of ti on a flat 4 but ive seen it on some inline ones Excels etc

and it being in the air filter its probly comeing in thru the breather pipe on the right hand rocker cover as they curve round and come out the hole next to the carby hole.

Here is some pic if that explanation didnt work...

Hey matak,

The oil colour is fine which is the weird thing, and the water level is perfect, havent had to top it up in a month or more...

then could just be some condensation which when oil gets splashed onto it it will turn that crap colour but there isnt enough to get carried back to the sump and discolour the whole oil

maybe as a precaution take it to a mechanic and ask for a Head check
its a thing of fluid that u put over the rad where the cap sits and then sucks in air and goes yellow (well ours at work goes yellow) if there is a head gasket leak

maybe this can be common on these engines as it is on some others.
if it doesnt do it during the warmer months then i wuldnt worry to much

Alright, while doing a uni assingment on pressure etc. i have come up with a theory to explain this (bar head gasket), my theory is that if their is lower than atmospheric pressure build up under the rocker cover the small leak that i have in the rocker gasket would perhaps draw in moist air...which would condense and end up in my air filter/under my oil cap....is this a crack pot idea or has university actually taught me something half useful? if so might just have to replace the rocker cover gasket...opinions??

Frosty2086 wrote:is this a crack pot idea or has university actually taught me something half useful?

I'd keep it quite that you've actually learned something... they'll charge you double otherwise!

Dunno about your theory, but i've had this in many engines, check your crackcase ventilation system, part of it may be blocked and not allowing air in or out properly. Its a natural thing, this is way crankcase ventilation systems were put on engines...

Happy hunting

Cheers el freddo, ill have to have an inspect on the weekend, probably get a mechanic to test her before the next outing too...