2009-2015 Cadillac CTS-V Performance Mods Discussion, Boost not building sometimes in Cadillac CTS-V Series Forum - 2009-2015; Hey guys so sometimes my boost is not building. If my car is running well the boost gauge will read ...
Hey guys so sometimes my boost is not building. If my car is running well the boost gauge will read 12 psi. I went out for a ride before and it wouldn't go above 5 psi. Any ideas? I have an automatic 2012 sedan with upper pulley tune thermostat and intake.
I just had the same issue with my 2009 MT with similar mods. Two possibilities I was told to look for were belt slip and also the boost bypass valve. Turns out it was a combination of both. To the left of the actuator on the bypass valve there is stop bracket with a set screw. If the bracket is not adjusted right or the set screw is in to far, the butterfly valve isn't completely closed and you are bleeding off boost. In my case the bracket was misaligned (should be straight up and down) and the butterfly was staying open. Also belt slip becomes an issue if you do not have an idler pulley which I will soon be adding. Hope that helps.
It is going to be the bypass valve, just look and do the pvalve mod, it is the easiest.. It will still shut off boost while non full throttle, so you don't have to worry about anything. It will just not be able to pull boost anymore.