RS-Ralph

.....the noise!

I have no clue what DV stands for, but the thread tells me you guys talking about an issue as old as the TT: The Re-Circulation Valve!

It's a terrible noise and the new part should end with an "H" as far as I can remember (...which has once in a while nothing to say :-)

Even if the check engine light is not on there is may a code (sporadic) stored in your ecm which links the tech to this valve. Should be something with 17...!

Ralph

RockiTT

This is a sound separate and distict from the sound of the DV opening. (duh.)

Lloyd of the Rings

1) the first noise you get with a dv as it starts to go bad is a "fluttering" noise often described as the "blowing over the top of a Coke bottle" sound. This is caused by the plastic diaphragm fluttering. This noise is eliminated by a replacement Forge or Bailey...as they have solid pistons.
2) the second noise, which can occur at any rev range, but is more likely to happen in the mid to high range, is caused when you do a "snap" backing off of the throttle. When you do that the oem dv and the Bailey/Forge pistons move to release the pressure to the intake side of the turbo to keep it spooled up. You will continue to get this noise when you replace the oem dv....but only when you do "snap" backoffs from the throttle.

I hope this helps.

RockiTT

The noise I am hearing *only* occurs when I snap off ther throttle between ~2800 and 3000 RPM - never above that. Further, I do indeed hear the DV open (working correctly) when I snap off the throttle at mid to high RPMs, and the noise I'm complaining about is a separate, distinct sound. It is a metalic "grrr" sound - commonly it happens twice: "grrr-grrr" only in the specific RPM range, uphill, throttle released. I'm now tempted to think it's some heat shield rattling, as the sound reminds me of the heat shield rattle on my old Honda when the engine mounts compressed a certain way under load while shifting.