what are you using for boost control? stock solenoids? mbc? 3port BCS?

to me it sounds like your wastegate is staying shut longer than it should/opening slower than it should. this would explain your overboosting. while the fluttering is normal (I experience it daily), my car does not buck. if your wastegate was still shut while you were relieving the charge pressure, you would still be building some boost, and this could explain the violent bucking.

answer my initial question and we can go from there. do you have the ability to log via evoscan?

 

The stock BOV tends to leak, so if you replace it with an aftermarket one you will likely overboost. So for example if you were tuned for 26psi and you slap on an aftermarket one you may hit 30psi or so.

 

Then i don't think it's the same issue, mine flutters in other gears, but doesn't shutter or buck at all... Only in 5th.

 

before you pull the trigger on a new BOV.. check for boost leak !

 

you can always crush the stock BOV if you have problems with leakage

 

How would one go about doing that?

 

I don't think Its a boost leak, It only happens about 3500 RPM, under full throttle no problems with the idle, just an overboost occasionally, which I presume is related to the BOV having a premature release of the air.

 

To me it almost sounds like it's having a hard time opening all the way, and just sort of pops open and closed. Maybe isn't creating enough boost at that RPM to open it correctly?

 

UPDATE: So last night I was driving home and cruising about 65 mph at about 3400 rpm, all of the sudden the whole car stuttered and then my gas pedal went dead and the ASC SERVICE REQUIRED picture appeared on the middle of the display. I couldn't keep the car going and had to pull over, once it reached idle the rpms were jumping from 500-2000 erratically. I shut the car off, waited for 10 seconds, restarted it and all was fine. Anyone know wtf could be going on? I just got my car back about 8 months ago from a big collision on the passenger front side and have had nothing but problems with the vehicle since.

 

I am no expert but the 500-2000 rpm cycling sounds like a MAF on it's way out. Also, could possibly by why it flutters etc as it's measuring the air wrong (just an assumption). Maybe it's still working well enough to not warrant a SEL to pop up as well. Anyone else that can chime in?

 

Bump for help ENGINE CODE WAS P1241

 

REPLACED BOV with new stock BOV and all issues have resolved, vehicle no longer overboosts, no stuttering, and almost completely silent during release of pressure.

 

That popping sound then idle bouncing and not drivable, is just an overboost, hitting limp mode. Happened to me in the winter on MBC.

Glad you got it sorted out.