Hello Guys,
I recently purchased a Supercharged Cobalt and have been having an issue with it. Under boost, the car sounds like there is a relay or something (Coming from under the steering wheel area) that is clicking and making the boost bounce back and forth from 12-18 psi. It does this as opposed to staying at a steady 15 psi. Seems to do it more frequently in the higher gears when the car is under a heavier load.

Any ideas as to what might cause this?

Thanks in advance!

 

Does it feel like the actual boost is changing? Is the car surging in power or pulling smoothly? More likely you have an issue with the gauge if the car is running normally, or possibly the car has a small pulley and the boost bypass not done, causing it to pull boost.

 

It's an auto meter gauge and appears to be working correctly.

When it does it, I hear something clicking, which leads me to think maybe there is a solenoid or relay or something causing it. I do believe there may be a slightly smaller pulley on the car. Makes about 15-16 psi. The car does not really surge, it seems to pull smooth.

 

Look up the boost bypass mod and perform that. That will rule out the car changing boost on it's own. Stock should only be about 12 psi, if it's higher the pcm will attempt to limit it if not tuned.

 

Measured the pulley and it's actually a smaller pulley than stock, so I feel like the car is attempting to try to keep from hurting itself. Ultimately, I am putting the car back to stock, so I am going to put a stock size pulley on it and see if that fixes the issue.