Head gasket blown or engine moisture?

[PenguinWithHair]

Hey everyone, my girlfriend has been complaining of her beetle (2000 2.0) not driving very well. The clutch is worn down and I've not experianced anything off with it so I basically told her it's her driving (eek). However...

Milky substance under the oil cap and strange deposits on the dip stick. Curiously though the coolant level is perfect. It has a fault code P0134 and pending codes P0422 P0171 P0116.

We've recently moved to an area where I've noticed I need to demist my window more often and our bathrom gets mega condensation.

So... Any ideas what experiments I can perform? What are the differing symptoms of an engine with some condensation to an engine with a blown head gasket?

Cheers guys.

 

[Burnerman]

Petrol engines used for short runs do produce water vapour which often manifests itself as 'mayo' under the oil filler cap etc, and usually longer hot runs solves the problem completely.
If the cylinder head gasket has blown then coolant will be discharged from the expansion bottle, and there will be oil present, more than likely.
A garage with the correct equipment can do a 'sniff' test of the gases above the coolant in the expansion bottle - a colour change of the chemicals involved can indicate products of combustion there.
John

 

[Burnerman]

Sorry, meant to add - that P0134 fault code refers to an incorrect lambda reading in the exhaust system - which indeed could be related to the symptoms mentioned above.
Its best to get the fault code cleared, and then see if it returns. I'd guess the engine management lamp is on here.
John

 

[PenguinWithHair]

Hey John thanks for getting back to me. It does say 'service' near the milometer, not sure if that's triggerd by clocking 10k miles or a fault but there's no engine check light or warnings otherwise. It has had a service, exhaust/cat, lambda sensor, cam belt/water pump within a year so fingers crossed it's not a write off just yet.

Could be a fault in itself that an engine light hasn't popped on, would you expect to see one with a broken head gasket?

 

[Burnerman]

Your fault codes all refer to exhaust system deficiency, which can be the lambda sensor(s), catalytic converter, even leakages or blockages. Curiously, this fault can disappear on its own if the car is taken on a long journey where everything gets nicely heated up.
Anyway, there wouldn't necessarily be a fault code thrown up with a slight leak, believe it or not so we can't guarantee anything at this time.
One thing I will say is that some aftermarket catalytic converters or lambda sensors aren't always what they seem to be, unfortunately.
On your engine, I'd like to see a compression test done, just to see what the compression figures are, and whether they are equal on all four cylinders. I would prioritise this first, I think as it would give some indication of the engine condition.
The service indicator is dependant on mileage, and not relevant here.
John

 

[PenguinWithHair]

Just had a look under the oil cap of my car (Astra mk4) and it's suffering identical symptoms. Either both our cars are buggered or it's possibly a local humidity thing or we possibly don't drive them up to temperature often enough.

If I may ask the question, I had an oil change about a month ago. Is it possible to experiance a moisture build up under the oil cap so quickly or can I suspect my car wasn't serviced very well?

 

[Burnerman]

Changing the engine oil doesn't touch the condensate you are seeing, unfortunately.....in fact if you were to take the engine top cover off, there would be one hell of a lot more!
There are however, some things to check. The gases and air pulses generated in the engine crankcase are actually fed to the engine air induction system by rubber breather pipes. They are visible around the air cleaner area. If these pipes become blocked with this grot, an increase of condensation (mayo) occurs. Its always a reasonable idea to see that they are clear.....personally I blow them clean with a huge blast of compressed air.
John