So a few weeks ago i noticed my car hit about 18 psi. I've tried a few things and can't figure it out. At first i thought the wastegate actuator was sticking so i sprayed it with lithium grease but it didnt seem to help. I also unpluged the wastegate solenoid and my car only boosted to about 7 or 8 which means that the actuator should be working fine. Im kinda out of ideas.

 

dude i have the same problem..mine boosts to about 15 or 16. where is the wastegate solenoid btw?

 

No one can help you if you don't provide better information. What mods have you done?

 

Intake, exhaust, DP. But i know its not because of my mods. You can boost to 18 just because of those mods.

 

well my downpipe is stock( the part mounted on to the turbo is stock...the rest is 3 inch exhaust all the way with a resonated mid pipe. aand i have hks type intakes.
everything else is completely stock. its a 99 spec engine.

 

So if my wastegate actuator was sticking could my boost be ok if i unpluged the wastegate solenoid? With the wastegate solenoid plugged in i overboost, but with it unplugged it stays at 7-8.

 

That tells me two things:
1) Your wastegate actuator is working ok (and you should keep it unplugged for now)
2) You could try replacing the solenoids or installing a boost controller instead.

If you want, you could try to tee into the line between the wastegate actuator and solenoid, then monitor the pressure in that line while watching boost. If your boost is above normal and there is less than 8psi in the wastegate line, you have found the problem. Personally, I'd test the solenoid off the car to avoid running over normal boost at all.

Dave

 

I just hooked up my boost gauge again today and noticed that with the wastegate solenoid unplugged i get 7-8 PSI on the first turbo BUT the second turbo is only hitting about 5.

 

If you have a midpipe (which you have not said one way or the other???) You could be boosting to 18 psi.

 

Dont have a midpipe.

 

I wouldn't be too surprised if you COULD boost to 18 psi in cold weather (makes overboost worse, of course) if the WG didn't open. The fact that boost stays at 7-8 with the WG solenoid unplugged indicates to me that maybe that solenoid is sticking open under some conditions.

Dave

 

So would that also cause me to only boost at 5psi on the second turbo with the wastegate solenoid unplugged?

 

IMO, yes. The primary uses the Pre-spool control as a boost controller, so it would not be affected as much as the secondary, or both together, which rely entirely on the WG opening for control. Nominally, it should be 7-8 psi, but if the gauge is off, or the WG spring is weak, you could read 5 psi after transition.

Dave

 

So which solenoid do you think is bad? The Wastegate Solenoid?

 

Yes, at the least.