wastegate malfunction?

raint5 · Post by **raint5** » 19 May 2010, 16:42

my 850 has recently began having what seems to be turbo issues, when i punch it the turbo will either spool to full boost and then seem to stutter, or will start stuttering at approx half boost, and not go past approx 6 psi, the only other thing i could think of would be possibly an ignition problem??? but other than that it runs good, any suggestions would be greatly appreciated

Post by **FlyingVolvo** » 19 May 2010, 17:23

Check all your vacuum hoses. I blew off one of mine on a long trip and it would do exactly that: Spool up, building some real power, then boooshh... all gone. I would push again, build up, more power, boom, no power...

raint5 · Post by **raint5** » 19 May 2010, 17:32

well i actually replaced all my hoses hoping that was the problem but it didnt help, is there any way to test the stock boost solenoid?

Post by **FlyingVolvo** » 19 May 2010, 17:35

Not sure about that, I'd wait for someone else to chime in. But when you replaced the hoses, did you make sure to properly hook up the TCV (Turbo Control Valve)? A hose in the wrong place there could cause issues.

FCPEURO · Post by **FCPEURO** » 19 May 2010, 18:04

You can test it is the solenoid or not by bypassing it. In other words, connect the vacuum line from the compressor housing to the wastegate and see if the turbo boost correctly. It should read about 6 PSI. If it does, then the solenoid is probably the issue.

raint5 · Post by **raint5** » 20 May 2010, 09:21

thanks FCP i dont know why i didnt think of that, i'll give it a try and post after that

Post by **charlyW** » 20 May 2010, 11:11

You can test the wastegate by removing the hose from the solenoid and connecting it upto a low pressure line give it some pressure upto 10 psi watch the wastegate for movement. as FCP says I imagine you've piped it round the wrong way been suffering with that myself

raint5 · Post by **raint5** » 20 May 2010, 15:44

ok so i just drove home for lunch, i didnt take the line directly from the compressor to the wastegate, but i punched a few times and hit full boost with no problems whatsoever

electrical? ignition maybe? now im really confused