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tooch
02-24-2005, 10:46 AM
My car (91 ST185 CS) is making this annoying high pitched whistle when the car is hot and at idle, or as soon as you lift off throttle. Goes away when any throttle is applied. I'm thinking its most likely a vacuum leak somewhere, its just hard to tell where its coming from.

Anyone else experienced this?

Mike431635
02-24-2005, 02:34 PM
Yeah I know the solution. Ship the car to me and I'll take care of it for you ;)

Nah, jk. Though you're free to do that if you wish. I'm pretty sure that sounds like a vac hose too.

ALLEN
02-24-2005, 05:26 PM
Had one on my 5fse, check the egr system.

corvelx
02-24-2005, 10:24 PM
I've experienced something similar.. but mine is only when the engine revs. I can't hear it under the hood nor can I when I am at the rear of my car. But from inside I can hear it real well.

And no, it's not wind. The car makes this sound from a standstill.

gen5
02-24-2005, 10:49 PM
As posted in another thread by one our admins, and I totally forgot about this, you can do a very simple check to find vaccum leaks. Take a can of carb cleaner, starting fluid, WD40, Liquid Wrench, or anything highly combustible, and closely spray around all your vaccum hoses. When the idle jumps, you found the leak; but don't stop after you find the 1st one, keep checking, as there can be several at one time. This trick also works for leaks in head and valve cover gaskets.

Trance4c
02-24-2005, 11:16 PM
Check your alternator and any hoses for boost leaks

tooch
02-25-2005, 06:56 AM
Thanks guys :)
Mike: yeah you can solve the problem if you want, but it'll cost you $14000AUD :D

I'll try the thing with the wd40/throttle body cleaner, gonna end up making a mess tho with all the bloody hoses!
Trance4c: Definitely not alternator whine, its an air noise, and only when idling so not boost leak. Thanks anyway :)

It doesnt happen all the time though, only some days...Seems to be warmer days

gen5
02-25-2005, 08:56 AM
Thanks guys :)
I'll try the thing with the wd40/throttle body cleaner, gonna end up making a mess tho with all the bloody hoses!
All that stuff dissapates pretty fast, espcially with heat from the motor.


It doesnt happen all the time though, only some days...Seems to be warmer days
I thought that was everyday in Australia?

tooch
02-26-2005, 12:53 AM
I thought that was everyday in Australia?

Not in Melbourne mate :)

BlackGT4
02-26-2005, 06:35 AM
how do you find which hose the vacuum leak is coming from.
i believe i also have a vacuum leak.. except in my one i can hear it as soon as i turn it on.. and it happens everyday lol.
i think i need to get my throttle body cleaned also.. something is giving me a shitty idle, and i think thats what it is.

Fraggle
02-26-2005, 07:12 AM
I had a shitty idle for a while on my ST185. I had it on the dyno a while back at Pro-tek, a fairly modest 106KW at the wheels. It ran really rich and was it was stuffing up the idle.

The mechanic fixed it slightly but I think I need an aftermarket ECU to fix it (or air fuel controller). I think part of the problem is the exhaust - I have a 3" dump pipe right up to the turbo and the oxygen sensor sits right on it.

Have you got an aftermarket muffler? That could be part of the problem.

-sorry don't know how to find a leak!

Punisher
02-26-2005, 11:32 AM
I have a can of Smoke In A Can.. shit is made for testing fire alarms.. :)

See if you can't find it at a hardware store.. it's a much much better way of finding vac leaks since it will get easily sucked right into any vacuum sources and it'll get into tighter spots.. if you just have a real small vac leak carb cleaner or anything else won't work for you because it won't cause an idle-up high enough to even notice.

gen5
02-26-2005, 06:43 PM
Good idea, I''l have to get some of that myself. Tanx mang

tooch
02-27-2005, 05:16 AM
Damn good idea....I sprayed tb cleaner everywhere and it did nothing, and just evaporated cos everything was hot!
Will get some of that smoke shit

InitialD93
02-27-2005, 07:24 AM
I have that same problem... oh wait thats just my turbo spooling and then blow off..... lol sorry had to do it :wiggle:

Trance4c
02-27-2005, 08:38 AM
Trance4c: Definitely not alternator whine, its an air noise, and only when idling so not boost leak. Thanks anyway :)


Just because its happening at idle, doesn't mean that its NOT a boost leak. That means it could very well be a boost leak because the system is in vac.

Good luck

tooch
02-27-2005, 11:39 AM
Yes but if the system is not under boost, how could boost be leaking?