Vacuum Leak?

[WinterVX]

I think I may have some sort of Vacuum Leak somewhere but cant really pin point where its coming from cause it only happens while under coasting acceleration, while tryin to maintain steady speed but not getting up to speed....if that makes sence.....

Anyway, I took off the engine cover checking around the purge hose etc, all is connected, looked around for other smaller black hoses to see if any cracks or loose connections, but found nothing out of the ordinary.

The sound seems to come from possibly in front of the firewall, and towards the passenger side of the car. Another interesting soft of leaking noise comes through when the air conditioner gets switched on, and again if you get down low in the passenger side you can hear it. Sounds like it might be related. A/C works fine, doesnt seem to be leaking gas as the air gets cold etc as it should.

I am aware that CAI does make a bit of noise while under acceleration, but Im not sure that this is the noise, as it seems to actually sound like a vacuum leak somewhere. Its kind of hard to explain, may even be described as getting a straw and breathing through it.

Anyone got any ideas?

 

[WinterVX]

Just made a quick call to a local Holden Dealer explaining to a tech there what I was talking about, he seems to think it would be worth checking out to see if a grommit has come loose from the firewall.....

Anyone able to offer where you would find these, and what they look like?

Cheers

 

[EXCESSV]

grommits are basically rubber caps that seal off holes on your firewal which people put stereo cables through and other items that need to go from the outside of your car to the inside.

they should be black. just get a torch and point it to your firewall. if there is a hole and nothing going through it then you found it.
you say its on the passenger side so that cuts down search time

good luck

 

[WinterVX]

thanks Deano, Ill have a look around. Still might take it to a Holden Dealer next week as a drive by check and see what they can find if I cant locate it.

Let you know how I go

 

[bradvt98]

i think there'd be heaps of threads on this because i'm pretty sure vt-vx are prone for vaccum leaks i have one to but i have no idea what i have to look for so it's not fixed yet. doubt it would be a gromit though someone told me something about it being the purge hose or something?????????

i'm sure someone on here has had the same problem fixed so they can tell us what the actual problem is cause i've heard heaps of people saying it's like 20 different things and really i don't want to go and replace all those things to find out if you get me i just want someone to tell me that definetly knows what it is

 

[WinterVX]

Least I know I aint the only one then.....But I dont think mine is a purge hose
vehicle runs fine when in idle

 

[EXCESSV]

if its the purge hose then you would know because it idles rough. kicks around quite a bit. and i know through pms with WinterVX that his isnt a purge hose but for $10 to replace new and a 5min job worth doing anyway

 

[bradvt98]

ok mine does idle roughly sometimes may well be that. would that cause the hissing sound ?

 

[WinterVX]

yes, in idle a loose purge hose causes a fairly loud hissing noise, and the engine runs quite badly

Take the engine cover off and check the purge hose below the throttle body
may be a that the hose at the 90° angle join has come loose. Happened to me once before
and thanks to Deano it was the exact problem

 

[ruso]

Winter VX I have the exact same noise coming from my passenger side, under the glove box. It's starting to get annoying especially under hevy acceleration. Gonna have a look later to see if there is a missing grommit, hopefully that's all it is.