I swear my car is possessed!! If I drive it a certain way, very light on throttle the bpv sounds like its working, and it will boost fine!

 

its on the turbo compressor, it has the electrical plug connected to it

 

Thanks ^

 

Everything has been checked, still can't figure this out!

 

Small boost leak?

 

Completely ruled a boost leak out, the problem comes and goes. One day it will boost fine, then the next boost about 10psi, I can't hear the bpv when it does this. This car is practically brand new, I just don't get it!

 

BPV diaphram sticking open sometimes would explain the random nature and the lack of you hearing it blow off when this happens.

 

Thanks term! Will check again.

 

Is it a stock BPV or a Forge? I lost track.

 

Stock bpv.

 

This is getting very frustrating, i took apart the bpv, its completely clean no rips or anything, when i pressed the diaphragm the spring shot out. Can the springs go bad? Also its still doing it when the car gets to operating temperature. When i first started the car up it ran fine and everything operated as it should, right when it gets near 180 it stops working. WTF!!!

 

Thanks for everyone's help, this fixed it.

https://www.cobaltss.net/forums/2-0l...st-mod-191361/

 

good stuff..... I tried that and iirc i got tons of flutter, i guess ill try again

 

get rid of that junk BPV and buy the forge one, i had this same problem when i was stock, i had the GM tune and that was it, so normally i was supposed to hit 20psi, but during hot days towards the summer, it would either stick open or closed, sometimes only getting 5psi and then others it would spike to like 26 and hold at 25psi..........once i got the forge BPV it all went away, even during the summer.......and im using the heavy spring with the Forge BPV.

 

Many people on here have issues with the forge unit also, not sure i want to deal with that. Issue has been resolved with this https://www.cobaltss.net/forums/2-0l...st-mod-191361/

 

thats weird cuz i havent had a problem O.o but how did you fix it? didnt feel like reading all of that, i skimmed thru it, and it talked about cutting some of those lines? yeaaaa i wasnt going to do all that lol.

 

Basically you buy a 6" piece of vacume hose and bypass the vacume tank.

 

and that gave it more boost? idk if thats something i would do being that the tune obviously wasnt meant for more boost the way it was tuned lol. but if its just 1-2psi guess it doesnt matter much. good thing its fixed though.

 

I didn't do it to gain more boost, I did it to see if it would fix the issue of the bpv not working, and the car not boosting, and it fixed it. Vacuum tank must be leaking or check valve inside is bad.

 

If bypassing the vac tank fixed it, then it's a leaky vac tank.

 

where is the tank? havent looked for it before. lol.

 

Yea I just said that lol.


The tank is located under the intake manifold. You can reach it from under the car and remove it with a 10mm socket.

 

oh ok, i prolly saw it when i took my IM off haha, just didnt pay any mind to it.