Noisy Turbo... when hot?

[Guest scottjuly79]

My car has started to make a high pitched noise when the boost is between 10-15 PSI. (almost sounds like a zipper). Below 10psi. it seems fine. The turbo is only about 2 months old, so I hope it's not coming from the turbocharger!

 

Any ideas???

[Drax240z]

Hey Scott, did this start happening just after your donut exhibition on Saturday?

 

I'd check all your IC piping hoses for leaks as a start, if it is leaking at high pressure only it would make sense.

 

I hope its something minor! Good meeting you Saturday.

 

Richard Lewis

[yo2001]

My turbo sounds louder when weather is hot

[zbuild]

I run 2 Bosch dump valves and when my boost goes up over 10 it sounds like an angry cat is loose under my bonnet. . .hissing and carrying on like a mad thing. The blow off valves leak over a certain pressure. . .they were designed for standard road vehicles that probably only saw 9 or 10 psi max. what sort of dump valve do u use? could it be that?

I also run a big K&N filter in my front guard (for nice cold air) I had a shroud that got damaged so I took it off. . . .then one day I drove in the rain, the K&N got wet, and my turbo would sound like it was spooling up on idle. . ..I thought Id killed my turbo! Just had to clean the filter and put a new shroud on to stop water and lumps getting on the filter. It was something to do with the turbo having lots of difficulty pulling air through the filter, and sucking the shaft of the turbo out of normal position.

cheers - Simon