Whistling noise when driving, and Climate control (issue?) in VZ Calais

[Meatpie_21]

Hey Guys,

this is my first post to not only this forum, but first post ever, so I'm probably completely in the wrong spot or something aha
So i bought this 04 Calais as a first car a while ago, and ever since having it, it has this whistling noise when you travel at speeds (anything above 80), like an air leak whistle. I've had people in the back of the car climbing around (including the boot) trying to look for the source of the noise, but just cant pinpoint where its coming from. have you guys experienced this before? what do you recommend?

also, if Climate Control is on, and i accelerate to 100ks, the output of the air (like face, feet, windscreen options) automatically cuts to windscreen, and will stay like that for a small amount of time. what does this mean?

thanks in advance

 

[Meatpie_21]

after looking through the forum, I've found that there are already posts about the CC turning to demist
http://forums.justcommodores.com.au...4-2006/183080-c-issue-under-acceleration.html
http://forums.justcommodores.com.au...04-2006/148481-vz-climate-control-issues.html

 

[adam_m]

Hey mate I've had a vz Berlina and now a vz Calais and both have the same aircon problem you mention, the berlina I had was much worse, when looking into it I found out the aircon direction controls are operated by vacuum created by the engine, when there is little to no vacuum being made by the engine under heavy load all the vent doors close and it's redirected to the windscreen so it can still demist for safety reasons. With my berlina there was obviously a vacuum leak somewhere so pretty much any acceleration made it revert to windscreen, with my Calais it only happens after long heavy acceleration periods or up hills etc, I'm still yet to determine if it's doing it like it supposed to from factory or there is a tiny vacuum leak in this car as well.

 

[Meatpie_21]

ah okay, thanks for that man, I appreciate the comment.
Mine doesn't really happen unless its under heavy acceleration, and it cuts back when i back off the accelerator anyway, it might not even be worth the trouble, unless it gets worse..
did yours get worse over time? or did it stay the same?

 

[adam_m]

Yeah my berlina got worse over time, or maybe I just started to notice it more once it got to the hotter months, but in the end it happened under normal acceleration on flat roads. It sounds like my Calais is like yours at the moment, and I can live with it for now, but I've thought about adding another vacuum canister in the line somewhere so it has a bit more reserved when it comes to heavy acceleration times.

 

[diysv6]

There is a small check valve (one-way) between the inlet manifold and the firewall on the alloytec. (Black end towards firewall).

If the valve is leaking, the vacuum in the vacuum tank under the dashboard will be diminished and under sustained WOT driving conditions, hills, etc. there will be no vacuum retained to keep the vacuum solenoids operated and thus the AC goes to demist mode for safety. Closing the throttle will increase the inlet manifold vacuum, and the tank will be re-evacuated by the inlet manifold vacuum, and the controls will work again, maybe for a short period of sustained WOT.

You could have a small leak in the vacuum tank/manifold/hoses/solenoids/vacuum switches etc where the AC/Heater controls etc are located, or the check valve is faulty.

The whistle could be the vacuum leak under the dashboard. Peering from the drivers side of the floor well using a torch will reveal a coloured nest of tubing - these are the vacuum circuits.

Hope this helps.

 

[balduf]

Hii...

Has solved friend?

I am in Brazil , I have an Holden VZ Alloytec 190 .... There is a vacuum valve that controls the position of the release of air , I decided in a simple way .