I recently replaced the stock S4 turbo with another one stock S4 turbo. At first I thought everyone went off without a hitch, but now I appear to have a coolant leak. The problem is that I can't find the source. It just vapourizes the coolant and I can't find proper traces. There was a tiny bit of coolant on the exhaust manifold, but it doesn't seem to be comming from the either bolt that holds the hard line onto the turbo. If it is flowing down, it's extremely slow. I can't get a particularly good view at the engine side 21mm coolant bolt, but I suppose it's possible that I didn't tighten it enough. The leak causes the car to heat up very quickly which seems somewhat odd given the lack of dripping coolant.

Ideas/suggestions on how to proceed? I don't want to take the turbo off again...

 

Bring the car somewhere to do a pressure test on the coolant system.

 

Judging from all the steam I can tell that it's leaking.

 

I should have been more specific, pressure test the system when the car is cold.

 

Snrub, if you can find some of that UV dye that is used to detect leaks, I have the appropriate light. I realized that just after we hung up the phone. A little die, and a slight pressure to the cold cooling system should make the leak very visible.

 

I had the same problem. New crush washers and gaskets solved the leaks for me. They were leakinging from the lines on mine.

 

thats what i would say you cant recompress old gaskets..

 

You can reuse the crush washers if you anneal them.

 

I pulled the turbo off and I can't find any logical reason for the large coolant leak I was seeing. If there was a small leak I could understand it. After a couple mins of idling the car will be well above normal coolant temps. Wanked FC, does this sound like the extent of your problem?

 

Check the flange where the coolant line runs off the LIM. A bad gasket there will cause a BAD leak! If not, check that the 60degree hose coming off the coolant return line isn't split, and shooting a stream of coolant at the turbo.

 

Well I've determined that the "new" used turbo must have some sort of internal coolant leak. Bizzar because I've never heard of this before. I put my old turbo back on and the coolant leak as stopped. Has anyone ever had this happen to them before? What could cause this to happen?

 

I hope it doesn't have a leak!

I don't have any idea as to how the coolant passages are routed internally in it, but is it possible that there is something clogged in one?

if it DOES end up that the turbo is bad, send me a message and I'll get you a replacement.