Recently my car started to loose a lot of oil very quickly into my cooling system on my 2000 Audi A4 1.8t. I found out after I noticed I lost a quart of oil in less than a 70 miles drive. If I open my coolant reservoir cap, in looks like a chocolate shake in there, but I am not getting much of any coolant back into my oil. I thought it might be the head gasket, but I had a compression test ran on the car and it passed, so I know it's not that. I also heard it may be the turbo that will send the oil into the cooling system, but I am getting the same amount of boost as I was before and I am not hearing any unusual noises coming from it, so I wouldn't think it was that. Does anyone have any idea what it causing this?

 

Your oil cooler is leaking internally past the diaphragm that separates the oil from the coolant. It's what your oil filter mounts onto. Remove it, flush your cooling system, put a new cooler on, change the oil, run it 50 miles, change the oil again, and you should be good to go.

 

I think a search would of found the exact same thread/answer. Last week we had this issue on another members car

 

I don't know much about the oil cooler, but I took it to a mechanic and he assured me that the oil cooler was fine. He didn't take it off, but he checked it out and showed it to me and said that was not the problem and was still leaning on it being the turbo. Is that possible to tell if it's bad by not even taking it off?

 

I don't know any way of knowing it's good without taking it out and proving there's no leakage past the diaphragm. If it's not the head gasket, and oil and coolant are mixing, the highest probability is the oil cooler. Turbo I suppose could be a source of mixing but man in 5-1/2 years of wrenching on many, many Audis and being here, I haven't seen or heard of it yet. Get a second opinion.

 

I will probably take it somewhere to get a second opinion early tomorrow. Thank you!

 

i would have to say that if your turbo is causing the issue..... then you haven't been keeping an eye on the coolant tank, cause the amount of time it would take for those little hoses to swap oil into the coolant system would be a while v the oil cooler and bigger hoses




are you going to a trusted audi/euro mechanic or some shmo down the street?

 

It is still the stock K03 with GIAC tuning chip. Like I said I am not loosing boost, nor am I hearing any unusual sounds from it. This is a problem that didn't occur over much time, possibly over night. I always like to keep an eye on my oil levels, and one day I noticed it lost a quart within a fairly short drive. I want to take it to the dealership but imagine it would cost a fortune, so I was considering taking in to Kalamazoo Imports.

 

But I will probably just take it to the dealership

 

Yeah your mechanic is trying to take you for a ride. Not without ESP could he possible be able to stare at the oil cooler without even removing the filter and tell you that its fine. He wants you to get a new turbo so he can charge you for replacing it. Go to a different mechanic or the dealer and tell them you think your oil cooler is bad, then tell them why.