Hey everyone,

I had another thread and it got old.
The issue I'm having is that my car seems to have fluttering when I'm in first gear, in vacuum. It's seem to happen when I rev my car up, lightly while keeping the boost gauze below 0psi. I can especially hear this is I'm driving along the side of a building and let off the throttle in first gear.

I had gm stage 1 kit put in about a month and a half ago. Was working fine except for the lower charge pipe blowing off the throttle body. Anyhow i got it reconnected and used a tbolt clamp to secure it. I decided to try my dejon intake, just to see how it would react. Well web I got into boost and I heard this high pitch squeel noise when I hit max boost. Not sure if this has anything to do with the issue I'm having now. I have since sold the intake and I'm on the air box mod with stock intake and k&n drop in.

I have done a boost leak test And everything is fine there. I'm making my second trip to my local dealer Wednesday to see if they can take another stab at it.

Do you guys have any idea as to what it could be, or what I can get them to check?

Sorry about the story book.

Thanks in advance

 

when it flutters are you still making full boost? I have the gms1 and have the same issue, but I don't make full boost...my bpv is getting stuck open and my car is at the dealer now for them to "fix" it.

 

Nope, I'm not making full boost, it's while I'm in vacuum.

How did they test your bpv.

 

Try checking that little rubber grommet on the BPV, that's been known to tear. The only reason I say that is that high pitched squeal noise could be air whistling out of it. Just a guess.

 

I have no idea how they'll do it, I only know it because I can't make full boost. throttle to the floor=5 psi when this happens.

 

My car still makes full boost fine... Just when I'm in vacuum, in first gear in lower rpms, is when it makes the fluttering. I could be wrong but the fluttering seems to make the turbo spool up slower

What rubber gromet thing..... The thing inside the bpv housing???

 

ya that's it

 

I'm gonna see if they have a way to test it

 

It's not a grommet, it's a diaphragm.

 

ok so I had the wrong word, but it got the idea across.

 

I had some flutter on the GMS1 at a maximum boost of 5psi because some of the wires on my cold side charge pipe, that TMPA sensor, the wires were loose, so Terminator told me to wiggle them, and push them in and whatever, and I did and it made it work again.

Good luck!

 

I had this problem. Might still. My harness was coming unplugged.

Keep a close eye on DTCs. Sometimes the car won't be throwing a CEL but it will be throwing codes.

P0236
P0238

 

Does the squealing sounds like a supercharger whine? That's what I heard when my clamps weren't tightened right. Under full boost it sounded like I was twin charged. Almost like a really loud whining/buzzing noise.

 

Take intake pipe off of turbo and airbox, take airbox lid off if you want. Take the three bolts off the tan cover on the side of the turbo and carefully pull cover off. It will have the spring and BPV diaphram inside. Be careful removing the BPV diaphram because the spring can shoot out unexpectadly. Check BPV diaphram for rips, tears, or pinch marks. Check the spring to make sure it is not broken or collapsed.

 

I'm gonna see if I can get the dealer to check it to see if it's damaged

How do you tell if the spring is bad, because I have nothing to compare it too

I remember the tech saying that he reflashed the computer before he plugged in the sensors. Would that have anything to do with my issue or now

Do you mean the wires going into the plug or wires going into were they were spliced.

 

I wiggled the wires going into the plug (the TMAP sensor).