Strange noise between shifts while under boost

[CajunKenny]

The sound is difficult to describe; but, it's sort of like a swooshing/chattering type noise. Sort of flappy too. It's the same sound of the turbo makes when spoooling and it does it every time while under boost. I have the 5 speed.

My turbo does have side to side and back and forth shaft play and here's a list of my mods:

3" full exhaust
K&N fipk
Shimmed Waste Gate (hitting 10-11 on cold days)

Everything else stock.

I'm thinking that it's a combination of two things. The shaft play in the turbo and the stock BOV is failing. :dunno:

What are your thoughts...?

 

[AR_91SupraTurbo]

My turbo made the same noise. Now it doesn't spool anymore.

 

[MDCmotorsports]

You sure you just haven't described your BOV?

 

[CajunKenny]

Well, that's not good. I'm hoping to be able to get the 57 trim upgrade in the next couple of months.:naughty:

 

[CajunKenny]

You sure you just haven't described your BOV?

Not sure. I hope that's all it is. I have a Porsche one I can put on. Maybe I'll do that tomorrow after I get my new aluminum radiator installed.:naughty:

EDIT: Sorry, I mis-read your reply. I have never heard a bov sound like this. Don't they usually make a very distinct sharp discharge type sound? If it is the bov, it's making a chattery type discharge sound.

 

[CajunKenny]

Ok. I'm off to nighty night. I'll check in the morning to see what you night owls have come up with. :biglaugh:

 

[bowsercake]

compressor surge? Is your BOV working?

 

[Quin]

Actually, there are several distinct BOV sounds. Make a video.

That sounds more like compressor surge to me.

EDIT: Damn it, Bowser beat me

 

[Boost_happy]

Its compressor surge, garranteed! my car did the same thing when i upped the boost, thought it was the stock BOV making the sound, but i changed BOV and it did the same thing. The stock valve doesnt flow enough with higher boost levels so you get compressor surge

 

[MDCmotorsports]

^Uh no. Unless the valve is broken. The stock ct26 wheel wont' surge in the stock housing, UNLESS THE BOV IS SHUT/BROKEN.

 

[Boost_happy]

Thats wierd cause my stock one did, i was running 15psi on it. i put an SSQV on it and it still did it a bit till i adjusted the spring tension on the valve. i have a FFIM if that makes a difference, but it did it with the stocker too. unless the stock BOV makes a fluttering sound....

 

[1992supraman]

yeah my bov was borken and i had compressor surge and as soon as i changed it no more chatter.

 

[1992supraman]

or if your turbo is absolutley shot then you can get funky noises but if its still boosting nicely then i doubt thats your problem.

 

[CajunKenny]

Ok. I'll start by changing the BOV.

Thanks guys!