I have just put an aftermarket air filter on my manual tt, when it comes on boost and i change gear it makes a chattering noise followed by the original dump valve noise.

 

What is the chattering? It sounds like a rally car...

I'm sure that I'll be corrected but I think the chattering on rally cars is either turbo stall or wastegate chatter, probably a few posts on here about it. I'd get it looked at as it could end up rather costly! Then again it could just be a loose spring in the dump valve... Sorry, that's not the best explanation but it's a start...

Turbo stall !!

Turbo stall !!

 

sounds like it!! Lovely noise but devastating for your turbos!!turn your boost down and see if it rids of the chatter!

 

If it is the wastegate the spring might be bust so it doesnt (open i think) properly!

OK, so just did a search on here and turns out that 'Wastegate Chatter' is a myth and/or incorrect terminology (sorry about that everyone, just showing my lack of knowledge there!)... it sounds like you have compressor stall which will kill your turbos quite quickly... are you running uprated turbos with external wastegates?

It's called compressor stall.

 

It happened when the back presure is causing the compressor to slow down to a hault. Not good for the turbo's.

 

Usually due to a boost leak somewhere along the line.

i would put my bottom dollar on it being your dump valves are too tight causing a pressure build up with closed throttle pushing the charge air back into the tubs causing them to stall. had it on mine, slacken them off and i bet it clears

 

 

;)

how do i slacken my dump valves off? will there be an allan key or screw on the side or something to open it up? or have i totally misunderstood? lol

if your DV's are in fact adjustable, there should be a grub screw of some description which you screw in to tighten and out to loosen.

 

have a read of this, it will explane every thing.....

 

http://www.balancemotorsport.co.uk/main.asp?sitepages=dumpvalves

I hate Dump valves, I ain't gonna hide that fact, but can you make the aftermarket DVs silent? Something I've always wondered.