Whistle noise when on boost?!

[W1 KRB]

Over the last couple of days my 1 has started having a high pitch whistle when coming on boost even when feathering the throttle, starts about 3k rpm then stops about 5k rpm, I wondered if it could either be a boost leak (doesn't feel down on power though) or a sticky dump valve, anyone got any ideas or experience with this? It's a standard car and standard dump valve.

[MUNK]

No that it helps mate but mines done it on and off since iv had it just thought it was normal... Usauly here it most from cold.. Never had any problems with it...

[W1 KRB]

My mate has a blob sti ppp an still has standard dump valve do putting that on tomo night to eliminate one possibility, will keep you informed

[W1 KRB]

Chang dump valve today and still the same...

[MUNK]

No one else had similar ???

[W1 KRB]

I'd like you and had a boost leak test done to see if if shows anything up, I've read about a few DIY kits but want it done professionally really!

[Devious]

had the same fault for about 3 months on and off.

Turned out to be a leaking gasket on the up pipe.
So only leaked when building boost.
Wasnt easy to spot as all looked ok. replaced gasket. and all is fine..

while the noise happened i found i was only boosting 1.1 - 1.2 bar

[W1 KRB]

Ok thanks, that will be my next point of call then, was it the up pipe to turbo gasket/ring or up pipe to exhaust? Think I've got the order of the exhaust right lol!

[Devious]

it was the gasket from headers to up pipe.

Its a weak link as these run 1.5 bar of boost.

But its worth checking all the joints and gaskets in the headers and uppipe

[W1 KRB]

Forgive me for being completely non mechanically minded but I have a Standard wr1, I thought the exhaust system went- turbo then down/up pipe, then rest of exhaust- centre section- backbox etc, where do the headers come in then?!

[Devious]

under the engine u have your headers/manifold which run to your uppipe.

if you look where you oil filter and sump is you will see the headers


your uppipe feeds the turbo

Jack up car/ 2 post ramp is much easier
remove undertray 4x 12mm bolts and loads of push studs
remove heatshield closest to oil filter and lamba sensor. (these will be a nightmare)

and the oval shaped exhaust flanges is the headers to uppipe joint

[W1 KRB]

Awesome, thanks very much

[Ant]

Also check the rubber gromets in the bulkhead are fitted correctly and havent been sliced for any wiring for additional gauges etc as this can cause strange noises entering the cabin.

[W1 KRB]

No extra gauges or wiring into cabin, thanks anyway though

[MUNK]

Would a whistle not be coming from inlet side of things..from hose somewhere in engine bay Rather than exhaust??

[W1 KRB]

I've established my one doesn't do this all the time now, been out this morning and all fine

[Devious]

Mine only did it when it felt like it.

some mornings fine. then on way home did it. or vise versa

drove me nuts