Over boost in3rd gear

[DantePasqual]

Hi, I have an 86 SVO with 132,000 miles on it, but only 40,000 since last rebuild and 10,000 since last turbo/wastegate change. In 3rd gear I'm getting an over-boost (18+ PSI) and get a metalic sound, before backing off. Any ideas on how to determine what's going on here? What controls wastegate openning? Vacuum?

Thanks,
Dante

[SVOeric]

sounds like you have a hole or leak in one of the boost controler hoses..

[SvoTy]

I agree with Eric about a leak in one of your vacuum hoses or wastegate itself. The "metalic" noise that you hear is detonation and you will not hear it too many times before you lose a headgasket.

Need to check out those vacuum hoses before you really tear something up.....

[DantePasqual]

Hi, Thanks for the replies, will check them out after I get the steering rack replaced (again). BTW, the celenoid[sp] that controls the boost? doesn't stay closed anymore. Could this be the problem?

I think the metallic sound is the turbo bearings about to be ground up! It's definately not detonation -- but that reminds me, isn't there a knock sensor that's supposed to stop that?

Thanks,
Dante

[SVOeric]

yes.. if the spring inside the boost controler is gone, that could cause it to go to 16 psi all the time

the metalic noise you are hearing, do you hear it when you romp on it, and then let off?? if so, that is pressure build up,and it is hard on the turbo.That is why people install bypass or blow off valves.