Oil in coolant


Registered User
Hi guys,

problem is with an 04 plate a4 1.8tq 190,

noticed this morning that there was a layer about an inch thick of something like chocolate milkshake, same colour and consistency, on the surface of the coolant.

the car is running absolutely fine, there is no water in the oil, never overheats, exhaust is a bit steamy for the first minute or two and then it's fine but I'm guessing that's just condensation evaporating. Hasn't lost any coolant at all since it was last chanced about 8 months ago. It has been using a bit more oil than usual though.

I'm hoping just the oil cooler is duff, I've had a head gasket go in an older 1.8 audi and it was far worse symptoms than this.

I need to keep the car on the road for another few days whilst I'm on call for emergency/rapid response at work before I can have it looked at properly.

Just drained only the reservoir and hosed it out to clean it and have topped it back up with water to see how it gets on.

anything else to check for in the meantime? And if it is the oil cooler as I'm hoping, is it a diy-able job?



Registered User
does sound a bit like the cooler under the filter. Think I paid about £25 exchange about 5 years ago for a replacement on my B2 .
Very easy on the 80 !
Lots more pipes/ less room on the B6 ( I have the same B6 1.8T 190 QTS car as well ) but should be fairly easy.
Check that the coolant pipes aren't 'welded' to the fittings on the cooler first, if necessary get some new clips as well. I didn't bother to fit new hoses even though they were over 20 years old - they looked and felt in good order.


Registered User
I'll get an oil cooler tomorrow, found one for £45, and try to get my hands on a Haynes or some kind of instructions.

After cleaning out the reservoir I was called out and did a 50 mile round trip on the motorway, checked it just when it had cooled down and haven't lost any and it hasn't clogged up with oily rubbish again yet and oil is still fine, I'm hoping I've caught it just in time as I do check it atleast once a week as it does have a fairly hard life (20k + miles per year).

Any info to help with the fitting would be gratefully received.



Registered User
Just a quick update to this,

I changed the oil cooler, oil, oil filter and flushed the radiator last Tuesday, and 800 miles later it looks to have done the trick.

Thanks kingfisher for the tips!