Please forgive the noobness nature of this, but I have a turbo question. My wastegate bolts recently started backing out. Due to the design of the manifold and the angle of my external wastegate, I was forced to removed the first charge pipe from the turbo and remove housing to get to the wastegate. Once I got everything back together, I cranked the car, let it warm up, and took it for a test drive.

Before I took everything apart, the car was set to 13 psi via vacuum T in series with the side barb on the wastegate. The wastegate has an 8 lb spring. While on the test drive I noticed the car was only going to 9 psi and holding steady all the way to the rev limiter. When I got back home I noticed a big "o-ring" of RTV in my engine bay. Did a little research on Google and read on a few turbo diesel websites that they run a bead of RTV between the housing and turbo... is this my problem most likely? If not, should I just be looking at the coupler to the turbo/charge pipe?

My turbo is a Precision SC61, if that info is needed.

 

Easy way to check and see if its the "RTV O-ring" your talking about would be to remove the compressor housing and look for an orange ring on the CHRA. If its there, its not what you think it is...if its missing...maybe youve found your problem.

 

Got the seal back in, but it's not any better. Hopefully boost leak testing tomorrow afternoon. Any more ideas until then?

 

It is a common misconception that this rubber ring is absolutely needed in compressor covers. Garrett does not use them and never has. Precision uses themas a way to keep the housing together with the backplate while rotating the compressor cover into position. Borg-Warner also does not use them.

That rubber ring will not change anything whether it is present or not.