Car not boosting over 2psi, what gives? (Friends vehicele, modded)
 

Good friend of mine just purchased a SS/SC via auction. Car is modified, however he is not aware of what is all together modified, so that makes this a little hard....

What I know:
Car has a smaller pulley set (I dont know what size)
Car has what appears to be a stock Cobalt LS/LT muffler on it

He says that no matter what the car won't pull more than 2psi boost, and there is NO check engine light.

Im not really sure what it could be. Boost solenoid? Bad supercharger to manifold gasket?

Any guesses/suggestions?

Thanks all-

bad gauge?

is the car still pulling hard? did it suddenly lose boost?
or is it just the gauge? they arent the best quality, and are known to crack up now and then.

if its actually only getting 2psi, the boost bypass solenoid is not closing. sounds exactly like what happened when i played with the boost inhibit in HPTuners. (it leaves the solenoid open constantly to disable boost)

easy test for this, pull the vacuum hose off the back of the bypass solenoid. if it builds boost, then the solenoid is bad

also make sure the belt is not slipping specially with a smaller pully

it has something to do with the bypass valve. had this issue for about...a month. lol.

Could be all kinds of things....
belt slip
bypass valve
bad tune....who knows... Not me that's for sure.

Check the electrical connector that goes into the boost solenoid. The little black box the vacuum line goes to. If it's unplugged, you'll only get 2-3psi.

I appreciate all the input. I suspected the boost bypass solenoid first as well. I have no idea, and Im sure he does not, if the car has had any HP Tuners tuning done.

I also suggested belt slip.

The car does NOT pull hard at all. I'll have him try the solenoid bypass and see what happens.

Which line needs pulled exactly, IMAGES?

Thanks,
Chris-

is the car black?

jersey auction?

is this it?

http://i143.photobucket.com/albums/r...SSCsprings.jpg

the boost hose popped off the top of the intake manifold on my old friends redline and he had the same thing, check that connection. it's under the fuel rail, behind the s/c.

lol @ Brian

This is going to get really bad really fast. :lol:

sorry the pic is shitty. its pouring rain outside and chevysalesman conveniently posted that engine pic :lol:

https://www.cobaltss.net/gallery/fil...oostbypass.JPG

Well, if the poster's friend bought the car that the engine pic is from well, nevermind :lol:

LMAO!! :lol: Good luck with that.

One thing. Didn't Brian's car have an exhaust on it?

did you sell a banged up car?

He didn't. I'll PM you a link to el story.

pm me one too haha

Broken NJ Cobalts FTW! lol

I'm actually quiet interested in the story aswell :)

my car did have a full exhaust on it. i can post pics of that as well

That's what I thought. I'm really curious if this was your car or not.

To the OP, we need more details on the car.

year/color.

well, the op is about 7 hours away, so i doubt his friend bought a car from jersey :lol: but i did the same, so i guess it's possible.

If he bought it at an auction, who knows where it ACTUALLY came from. lol

PM me the story too lol