Hi people,

So I was sitting in my car and decided to open the windows, so I give contact to give power to windows. I get a warning that my coolant is low. I'm thinking what can it be now, I see the tank its all empty, I top it off to only to find it all brown at the top and smelling like oil. WTF, the car was fine with the coolant two days ago. Car performance seems unaffected however I do notice a sort of rough idle as in the car seems to be shaking slightly while idling (rev idle is fine). I haven't yet checked the dipstick or oil cap to see if i can find anything out of the ordinary, will do it tomorrow morning.

From the reading I've done, looks to be head gasket or oil cooler.
I'm hoping to eliminate head gasket only due to the fact that performance does not seem to be affected.

What you guys think?

Regards,
George

 

Could be either like you said. When my oil cooler went (wasn't an Audi) the coolant turned into brown gunk. I also noticed no performance problems when this happened. When you check your dip stick and oil cap it will tell us a lot more. If both of those are clean I'd say oil cooler just based on my past experience.

I had my oil cooler done by the mechanic, $800. It was on a Saab so it was deep in the engine. Not sure where it is on an Audi.

 

On the 2.8, the oil cooler is stacked with the oil filter. I'm not sure if that is how it is on the 1.8t, but should be reasonably accessible. I would start by checking the oil cooler as it's much easier. Drain the oil and coolant. Remove the oil filter. The cooler is held on by large nut on a stud that passes through the cooler. There is a rubber o-ring that seals the cooler to the block behind it. My guess is that the o-ring failed allowing oil and coolant to mix.

 

Bad news
I check the dip and looks brownish milky, the oil cap has like a foam appearance around the cap. I started the car cold which turned on and stalled, tried again, stayed on and sounded like a car with upgraded cams and was rumbling. I guess the Head Gasket is gone.

 

If there is obviously water in the oil, why would you start it? A failed cooler/o-ring would allow the oil and coolant to mix (oil into coolant, coolant into oil). I don't think your evidence is enough to decide either way, but by running it with water in the oil you may have damaged bearing journals, etc.

 

I just wanted to see what would happen, I had a mechanic check it out, he quite certain its the head gasket has gone. I will get him to confirm by checking the oil cooler.

edit: had him check the oil cooler, cooler seems fine, he disconnected the two hoses and had the car run for a minute, no signs of oil leaving the cooler.

 

Bshusted, my understanding is that the o-ring that seals the oil cooler to the housing is only an oil seal (see this thread of mine for some pictures.) When the oil cooler causes the two fluids to mix it is because the thermal barrier between the two fluids has developed a leak internally, simply replacing the o-ring would not address this. The whole cooler must be replaced.

George, do not jump to the conclusion that it is the head gasket. The degree of difficulty and the cost involved in the two possible causes of your failure are vastly different. You do not want to deal with the HG if it was your oil cooler all along.

I would do a compression test and even try a new oil cooler before starting in on the head gasket. These cars just don't blow head gaskets.

 

Okay. I was miss-remembering the role of the o-ring. I still agree that this could very well just be a failed cooler and be a relatively easy fix.

 

Sure sounds like the head gasket to me. I'm just being realistic like the OP. It's unlikely that there would be coolant in the oil and oil in the coolant if it was just an oil cooler.

Oil in coolant, usually oil cooler, coolant in oil, usually head gasket, mixing in both, bad. At least from my understanding but I'm not a mechanic.

 

I had a look at the DIY BaseDrifter, my oil cooler didn't seem to have any oil surrounding the seals like seen in the DIY photos. The mechanic said the mixture was quite bad and that a lot of coolant and oil has mixed and vice versa.