Help with 97 GST!

[drocks22]

Hey guys,

My 97 Gst is having some problems. I always thought that it was running below boost, but this was confirmed when I bought a new boost gauge a few months back. The car will not climb higher than 5 psi! First thought, as it always is, is that this was due to a huge boost leak in the system. So we ran a few BLTs and only found minor leaks in a couple of the couplers and the BOV gasket. We fixed these until the system was able to hold 15 psi for a few minutes. The only leaking we were getting from here was a small amount out of the oil cap which appeared to be normal. I thought this fixed our problem, but when i took it for a spin, the fixes had affected nothing! I searched around on here for several hours and we could not find a match to the problem. I checked the wastegate and it was difficult to open by hand, so I assume it is in working order. Since I am getting such low boost, I have severe BOV fluttering, so I hope it isn't damaging the turbo. I only have a few very simple bolt-on mods: turbo-back exhaust, Greddy type-s BOV, Greddy hard piping, Prosport boost, oil pressure, and EGT gauges and full K&N filter pack. If you guys have any input on this it would be very appreciated. Thanks!

Dan

 

[BrokenTsi]

This problem is sometimes overlooked, but check to see that all 4 manifold to turbo bolts are nice and tight. I've seen those bolts back off and cause this exact same problem. Check for shaft play and make sure that turbo isnt damaged.

Also check for any restrictions such as a kinked coupler or intake pipe before and after the turbo. Even tho your boost leak test came out ok, it won't tell you that your intercooler is clogged or that your turbo is blown.

 

[Oliver@Slowboy]

This problem is sometimes overlooked, but check to see that all 4 manifold to turbo bolts are nice and tight. I've seen those bolts back off and cause this exact same problem. Check for shaft play and make sure that turbo isnt damaged.

Also check for any restrictions such as a kinked coupler or intake pipe before and after the turbo. Even tho your boost leak test came out ok, it won't tell you that your intercooler is clogged or that your turbo is blown.

True story! This has happened to me before.

Oliver

 

[BrokenTsi]

, most of the advice I give I have experience first hand, so its happened to me too!

As soon as I tightened up all 4, I went from 18psi to 25psi. And the turbo spooled faster.

 

[matt98eclipse]

My 2g with the stock t25 did the same exact thing wouldnt boost anything over 6 to 7 psi. Come to find out The rod on the wastgate acuator got bent somehow witch was not allowing the wastegate flapper to close all the way!

The way i checked this was i took a piece of vac line and connected it to the nipple on the compressor cover and on the other end of the vac hose just screw a bolt into it. By doing this you should be able to run alot amount of boost. So MAKE SURE you ease on the throttle and keep on eye on the boost gauge so you dont over boost!!

Might wanna check to make sure your wastegate flapper is closing all the way.