I dont know what it is. I just seem to keep losing coolant all the time now. I filled up my coolant tank today ran the car around the block for 5min and the temp shot up past the middle notch. and now my tank is empty. There is only a small drip under the car which is not enough to account for the huge loss. and now I havea foamy substance in my exhuast. does anybody know where this could be coming from. im thinking its a headgasket or a broken t-stat or water pump any advice would be helpful

 

remove the plastic engine covers and look around underneath where they fasten. The auxillary waterpump sits underneath the intake manifold and can is known fail.

It can be hard to tell when it's leaking, so be sure to get a light and really look around to see if there is coolant leaking from around the rear of the intake manifold.

 

oh man... if you see white foam coming out of your exhaust, sounds like you overheated your car, warped the heads, and now your leaking cooling into the exhaust manifold... sorry man. and by the sounds of it, your burning it pretty bad... your exhaust will have sweet smell to it, and you may see white exhaust plumes. its a good indicator.

 

I dont think its as serious as a warped head. The car runs with the exception of the heat. the smoke may be from oil still left when my turbo blew months ago. im only getting the foam in one exhaust tip. oil on the dipstick is normal so it very well may be old oil cooking because thats all I can smell.

 

Coolant loss seems to have stopped for now. I just put about 6 liters in and filled up to the max point. I bought a 3rd bottle as a spare. The car seems to run better the more I drive it. hopefully this sign of life keeps up.

 

I would still check your auxillary waterpump. Mine had a small leak and then one day the pump cracked completely in half and all coolant dumped out. Leaks just don't fix themselves... they only get worst.

 

good catch. I found a tiny leak in the aux waterpump. a new one is on the way.

 

If you are going to replace it yourself be prepared for at least 4 hours of work. It's not hard to do but you just have to remove a lot of stuff to get to it.

 

is there a write up anywhere? i think mines leakin too

 

Here's one for an A6 (2.7t). Should be pretty close. Looks like one of the larger differences is the intake manifold on the A6 having 18 bolts instead of the S4's 13.

http://www.audiworld.com/tech/eng.html