Creamy stuff under oil cap

Nope you've just described a stuck thermostat. Which will lead to condensation in the oil making Mayo. CHange it & it should go away after some motorway driving. You might have a dead head gasket as well but it doesn't sound likely & the thermostats a lot cheaper.

It can get like this even if there is nothing basically wrong with the engine if you don't drive it hard enough. If the engine never really warms up (a lot of short runs) or you drive it too gently, water builds up in the oil and you get this mayonnaise.

Best thing is to blast the car for ten miles or so to really warm it up and evaporate the water out of the oil. Do this every so often, depending. Gentle driving is bad for modern engines - strange but true.

Of course, you may actually have a blown gasket!

Rob Graham

=A0

Cheers duncan, thats made me feel a bit better-sound cheaper to fix!! steve

thanks Rob, actually I do 40 odd miles a day motorway driving to and from work, would that be considered blasting it? I average, ahem, 80 mph... cheers steve

That'll cure it, unless your thermostats dead.

I was reading the user manual for my Lupo the other day. I was interested to see it recommends not driving more than 1 car length in

1st and changing gear at 2000 rpm and try and get into 5th by about 50kmh (about 30mph(ish)). Probably not a great idea if you're joining a motorway ;) I've tried it and it's very gentle driving, can you drive a car too gently?

Regards,

Tim

My local mechanic recently mentioned that stats are a known weak point on astras, howeverhe didnt allude to which flavour engine.

Tom

My 1.4 Ashtray got through several stats in the five years or so that I owned it.

I did find out from that (actually from an AA repairman at the side of the road...) that the Haynes way of removing all sorts of stuff and the timing belt could be neatly avoided by just undoing most of the timing cover bolts and bending it enough to get to the stat - you have to watch the belt and make sure you put it back on the same notches, though!

It becomes a 10 minute job then, rather than a couple of hours. Which is nice.

Repeated sustained high engine rev plus uncontrolled overheating of engine oil is very bad news. Oil undergoes accelerated oxidation at the alarming rate of doubling for every 2.5C- 4.5C increase after 140C. See the sharp rise here:

Oxidative inhibitors in the oil will be exhausted much sooner. See the mileage scale on the Lt. Hence, apart from tackling the cause(s) of the erratic oil temperature indication and the mayonnaise as soon as possible, the oil needs to be changed too.

thanks Rob, actually I do 40 odd miles a day motorway driving to and from work, would that be considered blasting it? I average, ahem, 80 mph... cheers steve

Yes, I guess it would! There must be another problem, then. Thermostat maybe, as others have said.

Rob

I've tried it and it's very gentle driving, can you drive a

In my book, yes.

Rob

That's more than unlikely to be an issue if you've got mayo in the filler cap.

If Frank's Steve then who is Steve?

Stat is stuck open. HG is fine.

Change stat.

Tim. .

Stat's are a very well known weak spot ont he family II 8 valve engines.

Tim.