Coolant reservoir full of engine oil.

**George Riggall** · 16-10-2013,04:55 PM

Hi there,

After searching for hours on the net and having a mechanic look at my car I'm still not sure what's wrong with it. Do my symptoms make sense to anyone?

Nothing I've seen so far really matches up with my problem.

2005 Audi A4 Avant 2.0 tdi

My coolant reservoir is full of engine oil.
Bottom of oil filler cap has some clear/grey gel-like substance (water) on it.
Removed rocker cover - no sign of water.
Drained engine oil - no sign of water. Flushed engine.
Removed coolant reservoir and cleaned.
Rebuilt and idled car until it reached operating temperature - no sign of engine oil in coolant.
Went for a drive for about 30-40 min - coolant reservoir full of oil again.

Car seems to run absolutely fine. Good acceleration, no excessive smoke, no misfiring, doesn't get hot quickly, no overheating (I haven't done a long drive in a few weeks though).

Suggestions so far have been head gasket, oil cooler or cracked head. Every opinion seems to conflict with every other opinion.

Turbo and EGR valve were recently replaced. Car serviced regularly, usually by me.

Thanks in advance.

George

**Sam** · 16-10-2013,05:04 PM

You've done a lot, but you don't appear to have changed the oil cooler. It's a cheap part and an easy repair and 75% of the time it'll cure the issue.

Replace it and flush through the entire system a few times.

EDIT: When you say "full of oil" do you mean full of oil and water?

...and of course, Welcome to VWAF

**George Riggall** · 16-10-2013,05:15 PM

Thanks mycarsavw,

I was going to change the oil cooler on Tuesday, I bought a new one for £83. Then my mechanic phoned me Monday night and told me not to as he'd spoken to the Audi dealer and they said it was the head gasket.

So I took the oil filter back and got a refund.

The guy charged me £70 this morning to take my rocker cover off, flush the engine and coolant (with my assistance).

I personally agree with you, that the oil cooler is bad, so I will change it. But the price on an oil cooler is now £123.. Should be able to get it cheaper with trade discount..

Hopefully it doesn't rain too much tomorrow!

**George Riggall** · 16-10-2013,05:19 PM

The top is full of oil, there is water at the bottom (of the reservoir).

And thanks for the welcome, I may be on here a lot if the car keeps playing up!

**Sam** · 16-10-2013,05:32 PM

If there's no steam/smoke coming from the exhaust and you're not losing any water...

Has anyone done a sniff test (if the kit still exists of course!)

**Doctle Odd** · 16-10-2013,05:59 PM

Change the oil cooler. Remove the thermostat and reconnect the pipes. Dissolve a cup of Daz in boiling water and add it to a gallon of hot water. Fill the engine and drive for 10 minutes. It will clean it up perfectly. Then flush, refit thermostat and add coolant

**wheely88** · 16-10-2013,07:52 PM

When my Leon had this is was a mare. Started off as oil cooler and took forever to flush through (using dish washer tabs if I remember correctly).
After this event it got worse over years - first the coolant matrix, then the turbo and still, until I traded it in, it would lose coolant. Never smoked and passed sniff test. Was sure it was head or gasket in the end - but glad to get rid.
I must admit mine was picked up on a service and by then the coolant and most lines were quite thickly sludged up - so hopefully you've got to yours early enough.

**George Riggall** · 16-10-2013,09:47 PM

Thanks guys,

Hopefully I will be able to change the oil cooler tomorrow.

Removing the thermostat has been mentioned a couple of times. Is this simply to force circulation of the coolant system?

I did just notice the black coolant tank by chance, when I was checking the oil I think. I really hope it's not the end for the car as I do love it!

Fingers crossed.