I just got a new LNF dropped in my 09 after the last one blew, now after about 500 miles on the new engine I seem to getting a LOT of flutter/surge when I let off the throttle. I went to work today and rolled into WOT a couple times in third and everything was fine but when I got back into my car after work it was making the flutter sound. At any low PSI it would make a "shuttering/hesitant" sound when I let off the throttle and any high PSI it would just make a very loud sound of just air blowing out, no BPV noise at all. Performance seems the same though, could it be my BPV? My turbo? Any help is greatly appreciated

 

Bump

 

Anybody?

 

i don't know but sounds like a sensor of some type

 

I don't know, it hasn't lost boost, went into limp mode or anything

 

Bump

 

Start with both MAP sensors, CAI, and MAF locations. Also worth double checking the wastegate solenoid vacuum lines.

And read the codes!

 

did you put the mods back on it?

 

What tune if any? GMS1?

 

All the mods in my sig are on the car and put back on by the dealership with my new engine

 

What should I be looking for when checking the MAP sensors, MAF, and CAI? Could it be the BPV too?

 

And the weird sounds happen ONLY when I let off the throttle while in boost

 

Check the MAP sensors to ensure they are seated correctly. If they had the turbo off maybe they took off the BPV and tore it? My brother's car had ton's of flutter from a torn diaphram in the BPV.

 

GM just changed my turbo on warranty last week and it seems like im having flutter when doing short WOT... is the BPV on the turbo or is it separate? should i be upgrading to Forge with better springs?

 

What blew in the engine ? And if its fluttering was the.tune revise and changed. Also check for a boost leak or vacuum leak

 

Bypass valve is on the Turbo. Very easy to remove and check for tares. I think its 3 bolts, its a tan colored piece wit a tube clamped into the center of it.

 

i would start with a new bpv

 

check the bpv and the vacuum lines, i had work done on my car and they installed the lines wrong. but you are lucky they replaced your motor on your modded car, smh gm left me high and dry

 

you can remove it from above or you gotta go from under?

 

i bet its a boost leak, and its probably the BPV..get a forged one

 

My car has a new BPV and it randomly continues to have this problem as well. Wont boost passed 6 and sounds like a turkey gobble. Then it will randomly go away. Idk what is.

 

check your vacuum lines and your intercooler couplers or intercooler itself...there is a leak...mine is doing the same thing right now except it fully boosts afterall the gobble gobble flutter crap...lol