Having the housing replaced right now (driving a new Macan-S, not a bad ride, but not my turbo..)

I decided to do it preventively. I took a look at the pipes (requires removing the throttle-body, not a trivial task actually) and saw that one of the pipes had a line of glue out past where it enters the housing body. It looks as if it has moved out about 1/8-3/16" or so. That probably explains the whiff of coolant I smell after a hot/hard drive.

Let's see if I can find one of the photos I took..




Hmm.. couldn't find mine for some reason, but this photo illustrates the part in question. The two tubes are glued into the housing. They like to come loose and come out - eventually. The new design has the tubes bolted to the housing.

 

Don't forget to do the coolant Tees at the back of the motor. My '05 had the pipes and thermostat housing replaced before I bought it sometime but one of the Tees at the back of the motor let go and you end up taking the whole thing apart anyway. Do them while you are in there now.

 

One difference between a 955/957 and a 958 turbo - AFAIK no T's on the 958. Just the stupid glued in fitting on the side of the coolant bridge between the cylinder heads. I'm still thinking about that one. There has yet to be a reported failing plastic T on the newer turbos that I've heard about or seen.

 

You are probably correct, I wasn't thinking about the difference or what year yours was. I know the 957's still had the same issues. In that case.....nevermind!