Engine/Transmission (1994 - 1998) Wastegate

[dseabaugh]

Crawled under my truck to find a bolt I dropped when doing the dowel pin and I took a long look at the wastegate apperatus from the bottom side. What exactly does this thing do? How can you tell if it is working? Mine looks rusted up and from all apearances hasn't moved in a loooong time. Are you supposed to be able to move the rod by hand? How does lenghtening or shortening the rod affect its performance? I have had a lot of turbos over the years but this is my one and only wastegate. I remember reading about them in Poplular Science 20-30 years ago but don't remeber what they said they did either.

 

[illflem]

The wastegate diverts exhaust gas around the turbo when the boost gets to a set point to prevent overboost. With a wastegate you can get faster stool up at lower rpms without overboost at high rpms.

It's pretty hard to move the actuator by hand but you can check it with compressed air to the actuator, just don't exceed 30 psi. Main problem comes when the wastegate sticks open, then boost is slow to build and won't go as high. Changing the rod length will change the boost psi the wastegate opens. Many would say that having it stuck shut is a good thing and it is as long as your boost doesn't exceed 35 psi. Anymore than 35 is a waste, it will just raise your egts.

 

[Kalaehina]

What are the advantages of the 14 non wastegated housing?