Hi,

Car: 90 Vert with JDM Tii. Stock intake, BOV, turbo. RTek with 720s and 1000s with SAFC for fine tuning.

The car has been running fine for a year or more. Then one day it started whistling. Dont have a boost gauge but seems to do it under boost.


Here's a video. The sound is pretty accurate in loudness and pitch.

http://www.youtube.com/watch?v=DVfHf77uJTY

We pulled the intercooler and pressurized it. No whistles or leaks. We pressurized the throttle body and put an inflated ball in the exhaust to seal it up. There is air coming out of the unmetered inlet on the firewall side of the throttle body, but it doesnt whistle.

We pressurized to 30psi in the tests. The boost is stock at about 5.5psi.

Any ideas?

thanks,

Jim

 

Is your BOV operating correctly?

 

We pressurized at the intercooler inlet so that wasn't part of the test. I'm running all stock intake and try not to mess with the S-pipe too much since they are old and delicate.

You're thinking the stock BOV can fail and whistle like that?

 

turbine rubbing? shaft on turbo has play? oly happens wen ur boosting makes sence

 

howd you record it like that? lol

 

sounds to me like the turbo is done

 

Sounds like you got a slight boost leak.
Story: I installed a 90 mm throttle body.it would whistle slightly when on Vacuum.then when I Push on the pedal.it would go away.
I found that one of my TB gaskets was not adequate to seal the TB to the UIM,.
I made another one,and it went away,.
That is why I am saying Boost leak.

 

How'd I take the video? iPhone 4 with the top down and the hood off.

This came on suddenly. All quiet on a twisty road. Turn right at a stop light and it starts whistling. I'd think a bad bearing would build up over time. But I'll look at the FSM and see if it has a procedure to check the shaft play.

We also wrapped the air cleaner in Saran Wrap and then pressurized from the plastic pipe that comes out of the turbo but didnt get any whistling.

 

I don't know it sort of sounds like the bov isn't staying closed and is allowing a small amount of air to escape under boost.

If you wish to check the turbo for play just pull the air box hose off the turbo and grab the inside of the turbo and see if it moves in/out or side/side.

 

sounds like a toast turbo to me.

 

I agree it sounds like the turbo is going. I have heard some other turbos sound like that on YouTube.

 

I've heard of an issue similar to this. A common problem on Audi S4's that have had their boost turned up is a "hooting" noise. The stock bosch recirc valves will lose their seal and begin making a noise under boost. It's worth a check, but check for freeplay in the turbocharger shaft.

 

ive heard air pumps make noises like that you still running an air pump?