Emulsion under oil cap

[mvteng]

My 1.4 16v has had an oil emulsion under the cap almost from day one.

The coolant level never drops, & the oil when drained looks ok. I suspected a leaking cylinder head gasket, but my dealer investigated & pressure tested & found no fault. He insists this is a fairly common problem & is due to condensation?

Is he telling me a porky?

[ScoobyChris]

I know this is fairly common on the 1.6 used in the Octy engine so as long as the car is running right, I wouldn't worry too much about it Obviously Ross or someone knowledgeable will be along to correct me

Chris

[DGW]

I wouldn't worry unless there is other evidence present pointing to head gasket failure - which there apparently isn't. I had a head gasket fail on a Peugeot 505 and there were plenty of signs indicating this, ie a stream of bubbles in the radiator header tank, a rising oil level, loads of 'mayonnaise' in the oil filler tube, and poor cold starting followed by loads of condensation (vapour) from the exhaust.

[mvteng]

Thanks Chris / Denis.

car was running great until yesterday when it had its first problem in 40000 miles.

It wouldnt start & when it did it kept cutting out (almost like driving from cold without the choke on). The dealer replaced the MAP, & this cured the idle but it still ran really rough. He's now replaced the exhaust valve which had failed & which he thinks led to the MAP failure.

Up until yesterday, the car had been absolutely great. Nice to get the bill just before Xmas as well.

[robmawer]

Does it looks something like the below?

If so, that's pretty common, and is indeed caused by condensation apparently.

Rob.

[mvteng]

Exactly like that. Nice to know its nothing to worry about.

[Diving Pete]

If so' date=' that's pretty common, and is indeed caused by condensation apparently.

Rob.[/quote']

You can get 'mayo' under your oil cap if all you do is short journeys.

This is due to there not being enough heat to burn the moisture in the engine..

Of course, if supicious,

pull your spark plugs & see if any are a different colour. - any Haynes manual has the different colours & keep a check on your water levels.

Pete

[Fabia8v]

take it for a nice long drive, go and see some mates miles away, when you get there check again, it will more than likely be gone.

Worry ye not .

[Johnnyc]

What type of oil are you using? That looks like the effect of using a mineral based oil when you should be using fully synthetic. It's the water content that causes it.

[Puddenchucker]

What type of oil are you using? That looks like the effect of using a mineral based oil when you should be using fully synthetic. It's the water content that causes it.

My Octi starts getting the mayo under the oil cap as soon as the weather gets cold & damp, and that's despite using fully synthetic Castrol Longlife II oil. A typical journey for me (i.e. to & from work each day) is 23 miles each way, so it's not as though the engine isn't getting up to normal operating temp.

It just seems to be a characteristic (or desgin flaw :thumbdwn: ) of certain VW engines.

[Johnnyc]

I haven't had that problem in any car for years. The last time I noticed it was after my wife's 96 Ibiza went for service about 5 years ago. The car only had 30k on it and was fine before the service but within a week of getting it back, that emulsion crap was all over the cap. I couldn't get a response from the service guy by phone so I went down there and the mechanic let it slip that they just put cheapo £5 mineral oil in it.

It was a Skoda dealership too. They are gone now of course.

It's definately related to the water content in the engine and its ability to burn it off though. The water content of the cheapo oil was much higher and the Ibiza 1.4 Mpi engine just couldn't get rid of it.