Strange fluttering/rattling sound!?

[gsharrock]

I have a wierd problem , well actually my PT GT has a wierd problem. I noticed it ever since I installed the AMX1397 CAI.

When I back off the gas to shift gears there a very loud and annoying fluttering sound. I thought it was the factory surge valve, but I installed the AGP blockoff plate and TurboXS BOV and the sound is still there! So I thought it might be the stock wastegate actuator and hoped the AGP wastegate actuator (for an SRT4) would eliminate it. But since the AGP actuator won't fit, I'm still stuck with the sound.

Does anyone have any idea what is causing the sound and what I can do to eliminate it?[:I]

FYI, my boost is great with a rock steady 15 psi at WOT and no surge or falloff.

HELP!![xx(]

[Ian-PT-GT]

I had the same sound, As per Turbo gurus, there is still too much presure left in the intake tubes after the Throttlebody closes. The sound you are hearing, if you removed the factory bov, is the turbo being stoped by the air pressure left in the intake. you may need to instal a biger BOV or adjust the one you installed to open quicker. At high pressure, the turbo can explode and throw pieces of turbo to the engine.

$0.02

Ian

[gsharrock]

Thanks Ian! I will adjust my TurboXS BOV and see what happens. What BOV are you running or do you recommend? Did you get into the 13's yet? I'm rooting for you![^]

[PT GT]

got my answer on another post.

[GTPT]

I have the same sound in mine. The only mod I have made is the CAI.
I think the noise you are refering to is strictly turbo noise due to the fact that there are three silencers removed. Thats the reason they were placed in the intake system. There would be a great many people that purchased tubo PT's that would think their car was falling apart if Chrysler left them noisy.
Phil

[PK Cruiser]

I have the same noise to and all I did was remove the 2 silencers...I just though it as the bov...

[Ian-PT-GT]

If you have the BOV installed, It will most likely the BOV.

Try lowering the PSI to see if the noise will disapear.

When I set My Turbo to 12-13 PSI, There is a nice "SWOOSH"!

If you go over 14 PSI the Factory BOV, The way it is connected with those long tubes and a realy small connector at the intake tube, it will make the fluttering sound.

IF you want to test the BOV, disconect it from the intake and make a quick pass, If the noise is lower, Then it is the BOV. If the noise is the same, it is the turbo stoping and going at 85,000 RPMs. This could be catastrofic in the long run as the compressor will get stressed to the point of falure and pieces of shapnel will fly to the intercooler, and maybe to the engine.

Just think of this: If the Gauge makrs 14.5 PSI, The turbo is actually pushing 29.05 PSI or more to compensate for the Vacumm that the engine generates. Then, Look at the intake tubes connected from the Turbo to the Throttle body, It is about Two inches wide, There is a lot of air volume inside those tubes. Compare the intake tube lengh, Volume and presure to the small 3/4" BOV line.
You will see that it is to small for the air that needs to be released from the tubes (That is why MOPAR is getting ready to sell a better BOV). Not to mention that the Factory BOV leaks like hell when over 6 PSI, This could be the cause of the Boost drop off at high RPM.

I don't have an aftermarket BOV installed in mine, Exhaust Depot sells a nice kit for the car.

My experience with the APEX'i controller is that it works exaclty like the factory solenoid so I will buy the MOPAR Stage one Kit with the MOPAR BOV when it comes online and after learnig the changes MOPAR did, I will just add a little bit with my home tinkering.

The racetrack next to my house has been closed for the duration, The owner is selling it and untill the new owner gets up to speed, It will remained closed. No more racetracks available on the island. I Will keep the 13 Sec project on hold, No use to adjust if no track to test is available. I guess Now I have an A'PEXi available for sale for who ever wants it.

Ian

[RobGT]

Same as PK...thought it was the BOV.
Completely stock without silencers...
Should I be going in for service?
Someone should take a clip of the noise the way it should sound when letting off the throttle.
Im concerned...my GT makes this noise since day one!

[Ian-PT-GT]

Not to wory if stock.

Ian

[COP TZER]

these are ALL normal turbo noises, and are not detremental. They are simply the joys of owning a F/I car....