The Wastegate acuator on my 1990 TGP needs to be replaced. I called a friend at the dealer and he could not find a part number. Says only thing showing up for the turbo are a gasket and a bolt! Where can I get a good quality replacement? GM Part number?

I hope I'm describing the part correctly. The pressure activiated vlave that opens the waste gate on the turbo unit, that is bolted to the turbo, is round and has a rod that attaches to the waste gate are.  :D

Thanks!
Marco

It is a waste gate actuator...the only problem is most places do not sell that as a single item. When I bought a new turbo for my Sunbird it came with one that was adjustable. Very nice setup. I would try calling some turbo specialty shops and see if they will sell the actuator as a single unit... 8)

:?:

Will other actuators work on this unit? I have seen several used ones in the local wrecknig yards, on other pontiacs.

Marco

I honestly don't know but the actuator on my 1987 Sunbird GT Turbo had the same looking actuator on it. I would think that you could get one from a Turbo shop. Just tell them it is for a T-25 Turbo off of a TGP.

My actuator on my TGP went bad as well.  The diaphram on the inside would just leak all the boost out and the wastegate would never open.  I used an actuator off of a Turbo Sunbird.  I had a turbo sunbird t25 laying around and it looked pretty close so I tried it out.  It works and I think that both the TGP and turbo Sunbird actuator are set at 4 psi, but I could be wrong.  The only thing is that on the actuator where the vacuum line goes on...it's facing the opposite way, but no big deal.

Yes...both wastegate actuators are set to 4.5lbs for the actuator to move the .025" that allows the wastegate to begin the bleed-off. The soleniod that is up in the wastegate actuator loop is what controls the amount of boost the car is allowed above the 4.5lbs of preload that is on the diaphram. When I had the adjustable on the Sunbird it was nice because you set the preload to whatever you wanted and no matter what the solenoid wanted to do it would hold the boost pressure you set. Same idea as a regulator in line of the actuator loop... 8)