Itchy Dick

I have a Rotrex supercgharger on my MY05.

The VTA dump valve usually releases a big woosh of air when I change gear. Whilst driving you can always hear a constant low noise sssshhhh noise.

I started the car up and it idled at 3krpm. I swiftly turned it off and then back on, everything fine. I then put my foot down and change gear and the noise is totally different. There's still all of the boost, no percievable power loss at all.

The noise is now more like a sh, sh, sh, noise going from high volume to low. On constant, it's now doing the same. It's almost chnaged to a chatter sound.

Had a quick check of the pipes and everything seems OK.

Anybody any ideas?

Thanks,

Nick.

Edit - It's running a systec dump valve.

WinFreak

Dumpvalve blocked or knackered so you get compressor surge, hence the chatter?

Just a guess there though, best wait for some proper answers

MB

Tend to agree.

If you are getting full boost it's not leaking, so it's probably stuck closed. Get it in bits!

unclefester

Snapped spring in the DV?

Itchy Dick

Good news - Just gave it a dose of 9krpm and it's fine! You could hear it made a 'pop' and then all of a sudden the original sound was back!!!

Thanks for the responses - I think you were both correct, a stuck diaphragm!

martin j

Regardless I would still strip and clean the valve in case the obstruction has merely shifted and is still the system somewhere ready to reappear.

CB

Hope all OK Nick!!

Itchy Dick

Yeah, I think so! Drove about 30 miles since and it's been nothing but perfect!

Geez I love this car!

It's getting a full correction detail next week, can't wait! Just waiting for some products from Tango.

Nick

Xd

They were posted Friday Nick, enjoy.

Itchy Dick

You're a star!

A1 service all the way.

Thanks

Nick.