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Location: Perth
Registered: October 2003
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Annoying high pitched whistle noise when on boost
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Sun, 01 May 2005 06:01
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Ever since I finished my conversion ive always had a real annoying high pitch whistle when boosting hard >6psi. I always thought it was my boost gauge crushed olive or something, today I finally removed the line from the back of the gauge, olive was fine so then I removed the line from the engine and the noise continues, so obviously not boost gauge. The only other thing I can think is the brake booster but I don't want to go removing the line to that and driving the car. Ill try putting a bit of air into the booster with a compressor, could it be anything else?
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Location: Brisbane
Registered: February 2003
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Re: Annoying high pitched whistle noise when on boost
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Sun, 01 May 2005 11:42

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don't try to pressurise the booster - it's not designed to see boost.
there should be one-way valve between booster and intake manifold so it only gets vacuum - find a valve from a wrecked car and see if noise continues
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Registered: December 2004
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Re: Annoying high pitched whistle noise when on boost
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Sun, 01 May 2005 15:39

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could be the turbo?
mine makes a strange whistling sound around 3500RPM.. i don't know what it is.
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Location: Adelaide
Registered: May 2003
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Re: Annoying high pitched whistle noise when on boost
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Sun, 01 May 2005 22:09

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I had a hugely minor leak (about the size of two pin heads) in a rubber joiner which was letting air through on boost and acting like a whistle.
Sounded fully sick.
Needless to say that joiner got replaced
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Location: Sydney
Registered: April 2004
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Re: Annoying high pitched whistle noise when on boost
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Sun, 01 May 2005 22:37

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yeah i was getting that whistle on my gze,
i think i found the problem to be a pin head size leak in a weld on the sc outlet.
my guess would b that u have a small leak
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Location: Perth
Registered: October 2003
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Re: Annoying high pitched whistle noise when on boost
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Mon, 02 May 2005 00:26

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thechuckster wrote on Sun, 01 May 2005 19:42 | don't try to pressurise the booster - it's not designed to see boost.
there should be one-way valve between booster and intake manifold so it only gets vacuum - find a valve from a wrecked car and see if noise continues
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I did research on this brake booster pressurizing issue when I originally did the conversion. Apparently they all have a one way valve built into them?
To takai and ke35, did your noise sound like it was coming from inside the car? My noise doesnt sound like it's coming from the engine cause it's so intense inside the cabin.
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Location: Adelaide
Registered: May 2003
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Re: Annoying high pitched whistle noise when on boost
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Mon, 02 May 2005 01:21

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Yeah, mine reverberated throughout the cabin, mainly sounded like it was coming from the trans tunnel.... in an fwd.
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Location: Sydney
Registered: April 2004
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Re: Annoying high pitched whistle noise when on boost
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Mon, 02 May 2005 02:24

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when on full throttle therefore more than 8psi the sound was REALLY loud!!
but im pretty sure it came from the front cos i had ppl drive in front of me and say it was really loud so asked some1 to drive behind me, they could hardly hear it
so yeah im saying engine bay.
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Location: Perth
Registered: October 2003
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Re: Annoying high pitched whistle noise when on boost
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Mon, 02 May 2005 04:49

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Well thanks for that.
Now ill have to go over every vac line with a fine tooth comb
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Location: Perth
Registered: October 2003
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Re: Annoying high pitched whistle noise when on boost
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Mon, 02 May 2005 04:52

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Well thanks for that.
Now ill have to go over every vac line with a fine tooth comb
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Location: Perth
Registered: October 2003
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Re: Annoying high pitched whistle noise when on boost
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Sat, 07 May 2005 08:39

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Yep it was the booster.
I pumped compressed air into the intake manifold and pulled lines off until i found it.
Off to get a one way valve
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Location: Brisbane
Registered: February 2003
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Re: Annoying high pitched whistle noise when on boost
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Sat, 07 May 2005 09:17

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you also might want to check the booster to make sure the diaphram hasn't been holed/damaged by pumping air into the poor thing
it should hold a vacuum
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Location: Perth
Registered: October 2003
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Re: Annoying high pitched whistle noise when on boost
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Sun, 08 May 2005 03:06

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It still holds a vacuum as I get a few pumps of the brake pedal when I havent driven the car in a while and the engine is off. This is the reason I thought all brake boosters already had a one way valve installed.
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Location: Brisbane
Registered: May 2002
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Re: Annoying high pitched whistle noise when on boost
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Sun, 08 May 2005 04:27

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Hi guys,
I'll just say thanks for your replies in this thread as I had the exact same prob in my chaser, I just disconnected the brake booster line and the high pitch squeal went away!!!
I've got a spare brake booster for it so I'll swap that one in.
I've been trying to isolate this noise for a couple of months now, it sounded like an electrical buzzer and I'd basically lost hope of finding the noise and was about to remove the turbo's to check them out 
Jason
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Location: Brisbane
Registered: February 2003
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Re: Annoying high pitched whistle noise when on boost
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Sun, 08 May 2005 11:44

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jasonp1977 wrote on Sun, 08 May 2005 14:27 | Hi guys,
I'll just say thanks for your replies in this thread as I had the exact same prob in my chaser, I just disconnected the brake booster line and the high pitch squeal went away!!!
I've got a spare brake booster for it so I'll swap that one in.
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woah there ... it's not the booster - it's the lack of a one-way valve.
most toy's that i've seen have it inline between manifold and the booster - i do recall chrysler (bro' had a VJ ute) had them as part of the vacuum port on the booster - as did my mum's old Ford (PBR?) Cortina.
cheers,
Charles.
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Location: Brisbane
Registered: May 2002
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Re: Annoying high pitched whistle noise when on boost
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Sun, 08 May 2005 11:53

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yep, I meant to edit my post earlier after having a better look at the car. Mine originally had a 1GGTE in it which had a 1 way valve integrated into the hardline from the brake booster that bolts to the firewall. I replaced that hard line with the item from my jzx81 frontcut which doesn't have a valve in it and neglected to swap in the jzx81 booster aswell (original GX81 booster stayed). I put in a metal 1-way valve earlier and it's all good now.
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Location: Sydney
Registered: April 2004
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Re: Annoying high pitched whistle noise when on boost
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Sun, 08 May 2005 13:13

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ive got a one way valve on mine, but i assumed that was because there is manifold pressure and that the booster only likes vacuum.
do N/A cars usually have a 1 way valve??
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Location: Perth
Registered: October 2003
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Re: Annoying high pitched whistle noise when on boost
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Sun, 08 May 2005 23:29

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Well my cruiser doesn't but it's a different case all together as it was turbo, but because it was a diesel it also had a vacuum resivior.
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Location: sunny coast, qld
Registered: October 2002
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Re: Annoying high pitched whistle noise when on boost
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Mon, 09 May 2005 02:09

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My stock ke70 has a one way valve so I guess NA cars usually have them as well.
I changed booster as well and forgot to fit one way valve but then installed it later. Didn't drive the car without it installed so don't if it would have whistled?
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Location: On your mum!
Registered: May 2002
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Re: Annoying high pitched whistle noise when on boost
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Mon, 09 May 2005 02:44

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Sounds like the check valve may be making the noise. Try replacing that.
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Location: Sydney
Registered: April 2004
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Re: Annoying high pitched whistle noise when on boost
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Mon, 09 May 2005 05:12
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yeah i also checked on my ke70
and it has the valve as well...
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