Evening,

MY2001 WRX.

I pressure tested all the pipework i could and there were a few small leaks so Ive replace the leaking hoses with new.

Still Ive got this loud whistle noise when on boost.

Any ideas? Intercooler is the only part Ive not pressure tested as the leak tester hoses etc wouldnt fit.

Thanks in advance.

 

Check your turbo inlet pipe ( pipe from maf to turbo )for splits also do you have a dump valve fitted? If so what sort?

 

Ive pressure tested the turbo inlet pipe and up to the dump valve. That all held pressure with no leaks.

Its still the oem dump valve. I even bought a brand new gasket for it hoping that was the leak but its fine.

Theres no loss of power just this annoying whistle sound That never used to be there.

Cheers

 

i had the same problem other day and mine did turn out to be the turbo inlet pipe... i would start by pulling off your intercooler and checking pipes also gaskets on the intercooler.

 

I disconnected all hoses off the turbo inlet pipe, plugged them and pressure tested. There were a few small leaks due to the old hoses being disturbed and hardening of the rubber. I replaced them and fixed them small leaks. So all pipework holding pressure except the intercooler its self and that pipework as that all had to be removed to pressure test rest of the pre turbo pipework.

I know that my exhaust is blowing at the joint after the sports cat to the next section. Thats under the car. But would the exhaust make a whistling induction type sound?

 

yes your exhaust could cause this issue

 

Hi scooby_impreza,

I finally got round to replacing the exhaust gasket and that did not stop the annoying whistling noise, just thought I'd let you know.

Is it common for intercooler to develop an air leak?

 

We had the car up on ramp with it running in gear. Could not get the noise to show!

Will turbo not boost if car not under load like wheels on ground and moving?

Any way to fool it to give full boost to find this bllody annoying whistling?!

Thanks

 

has it still got the pre turbo cat up-pipe fitted, I've seen instances where those have started to break up which cause loud whistling noises

 

hi

No cat pipe there. I fitted decat pipe when remapped a few years ago.

Cheers

This is tedious

 

My daughter has a similar problem I was told to try easy start spray whilst the car is running spray around the pipe work and any leaks would suck the spray in and you'll notice a change in the engine note

 

If there was a leak on the intercooler would the car even idle?

 

have you checked the Y pipe for the TMIC ?

 

Yeah it all looks ok. I bought all new Mishimoto y pipe. All hose clips are tight. That pipework and the intercooler itself is the one piece that i have not pressure tested. Thats why I ask if the intercoolers are prone to leaks?

Cheers

 

the Y pipes are . . .

 

They're what?

 

Prone to leaks I presume.

I would think its the turbo inlet pipe. Most common issue with leaks.

 

[QUOTE=ScoobP1;11764100]Prone to leaks I presume.

yes just re read it. Makes sense now.

So the turbo inlet is the pipe from the air filter with a bend on it? The one that looks a right tw@t to change?

Has anyone else heard the same annoying whistling sound themselves or just what they've read about? It can't be heard on tickover at all, just on boost.

Cheers

 

Do turbos make a whistling sound if they're at all knackered?

 

Yes.
Had this on a blobeye WRX ( TD04 ) recently and it was the impeller shaft partially seized.

Mick

 

Check the connection between the intercooler and throttle body (the hose). It's not clamped up properly possibly.

 

Manifold to up pipe gasket can make a screaming noise.

 

Good luck with finding the answer. There is nothing worse than an annoying noise you can't get rid of.