Coolant mixing with oil, but NO oil in coolant. Why?

[catamount90]

Hey guys,

I've got sort of a weird issue. I'm losing lots of coolant into my crankcase. It goes down quickly. However, my coolant res is clean as a whistle... no oil residue to be found. It's mostly water at this time (because I've been adding so much) and it's 100%.

My question is this: what could cause coolant to leak into the case WITHOUT forcing oil out into the cooling lines? I thought that the oil pressure was much higher than the coolant pressure which would almost always lead to oily water.

Any ideas? Could a busted oil cooler cause this?

Pertinent info:

- Compression good across the board
- Engine doesn't overheat (as long as there is enough coolant), stays at ideal temps

[Dubsport Inc]

Could be a headgasket leak that is causing oil to get into the oil return drains going back from the cylinder head to the crankcase.
HTH

[foley803]

Wherever your leak is, the: coolant pressure > oil pressure like what he said ^^

I think this would eliminate the oil cooler. I also think I've read that there is a certain head that is prone to developing a crack near one of the cylinders, but I don't know which one..


(Hey, my name is Richard too! You know what they say, 'Two Richards don't make a right')
Well, except in this case, because I'm agreeing with him..

-Rich

[catamount90]

Thanks, Richards! What would your next step to diagnose be? A pressure test? Or would you just pull the head.

Also: I get a puff of smoke upon cold start that goes away after about 10-15 seconds. Seems more like steam than oil.

[foley803]

I would pop out the spark plugs and see if the top of one of the pistons looks like it's been steam cleaned (Head gasket). Beyond that.. I'm not sure what the next step would be.

Maybe one of those tests to see if there are combustion gasses in the coolant.. But if its the head gasket leaking into an oil drain, then this test wouldn't find it.

There are many on here that are more 1.8t savvy than I, so hopefully someone else will have more ideas before you have to pull the head.

[catamount90]

I've already checked all of the pistons and they look grungy and dark, not at all what I would expect to see if the head gasket was bad. I guess perhaps the head itself might have a leak between passageways in which case the coolant would never make it to the combustion chamber.

I'm just wondering if there is a way to figure that out before pulling the head.

[seanj130]

Oil cooler puts oil in coolant... Head gasket will be coolant in oil as you have described.

[Charles.waite]

Have you inspected around the thermostat and rear flange for signs of a leak (crusty pink coolant residue)?

The rear flange drips coolant onto the transmission bellhousing so thats the easiest way to spot a flange leak (you can't see it otherwise).

I could be some coolant leaking from the turbo itself. Not sure if thats possible. I would check that the coolant lines on the turbo and make sure they are snug.

Also check to make sure there isn't coolant pooling in the cylinders after the car sits for a while. The white puff on startup is usually indicative of that.

[03a4sport]

Sounds like my HG problems. Coolant was pink and no oil. Ended up with a pin size hole in Cyl 2 (AMB head). I kept replacing my HG thinking that was the issue and turned out that it was my cyl head. New head and issues went away. HG kept going bad between Cyl 2-3. Did the test for exhaust gases in the coolant and that's what led us to diagnosing the bad HG, but I never thought it would be my head. Good luck.

[boy412]

I had a leaking water pump that I couldn't see (until the front clip was off). Good luck! Be sure to post back when you find the culprit...

[foley803]

Sounds like my HG problems. Coolant was pink and no oil. Ended up with a pin size hole in Cyl 2 (AMB head). I kept replacing my HG thinking that was the issue and turned out that it was my cyl head. New head and issues went away. HG kept going bad between Cyl 2-3. Did the test for exhaust gases in the coolant and that's what led us to diagnosing the bad HG, but I never thought it would be my head. Good luck.

That's the one I was thinking of, thanks.

[evo_ski]

Any updates on this, sounds pretty much exactly like my issue.

[A4Maine-iac]

X 2. Replaced my oil cooler = no dice. Thinking it is a tiny leak. Get the cold start smoke show then after about 5. It's all gone.

[craftyvtec]

I am having same problem, did anyone ever figure out a fix?

[diagnosticator]

Oil pressure is always higher than coolant pressure. If the coolant is getting into the crankcase, it can only do than from a bad head gasket leaking coolant into the crankcase via the oil drains from the head.

[jschuholz]

Coolant can get into oil by blown turbo. Why do you say coolant getting into oil is definitely blown head gasket ??? I've worked on more than 20 1.8T engines and have never seen a blown head gasket yet. Please explain ????

[old guy]

Could be a blown turbo, could be a blown head gasket. Stick around AZ for a while and I am sure you will see numerous posts about blown head gaskets. Once you overheat a 1.8T you will find that blown head gaskets are rather prevalent.

[Johnny1.8T]

Couldnt you try a cooling system pressure test? Its a hand pump with a pressure gauge along with an adapter that screws into your coolant reservoir. Pump it up to X psi (not sure how high you should go) and let it sit for a while. If you have a decent size leak, whether internal or external, youll see the gauge drop pressure quickly. If it doesnt drop off pressure quickly, let it sit and check on it every few minutes. If it drops a little bit every few minutes you know you have a small leak. I would do that before pulling the head or doing anything major

[evo_ski]

Johnny, that is exactly what i did and how i diagnosed my blown gasket. I pumped it to 14 psi and after an hour there was a puddle of coolant in cylinder 1.

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[KJack]

Sorry to dig up an old thread, but I'm having the exact same issue now. Has anyone determined a cause?