Airvents changing under soft acceleration

[Malus]

I'm having the usual issue with the air vents changing from face to windscreen under soft acceleration. eg; sitting on 100km/h and going up a slight crest it changes. Very annoying
My issue is that i have climate control and i've checked and rechecked the seals on the soleniod sellector, vacuum tank and on the non return valve on the plenum. All seems to be ok.
Is there anywhere else that could cause a leak?

Also my electric antenna wont go up or down. I've checked the wiring and all is fine and the antenna works if i used another power source. Does the BCM have anything to do with this?

Thanks in advance

[Steven M]

Hi, I have the same problem. I have already replaced the solenoid unit which cost me a 110 bucks and the one way valve behind the intake manifold but has done nothing. Any ideas, of what else to check.

[Steven M]

also where is the vacumm tank located

[accentstencil]

also where is the vacumm tank located

Behind the glove box.

[Malus]

Remove the pastic cover under the dash that you pulled off to get to the soleniod unit. and the vacuum tank is on the left hand side of the fan.

[Steven M]

cool, i'll check that and let you know how i go because if that ain't the problem, then we definately have the same problem. Cheers

[Malus]

Hi, I have the same problem. I have already replaced the solenoid unit which cost me a 110 bucks and the one way valve behind the intake manifold but has done nothing. Any ideas, of what else to check.

From what i can guess, under acceleration the vacuum gets too much for the seals in the soleniod unit and the little springs that push the seals closed cant cope.
The replacement unit you got, was it new or from the wreckers?

[JAM3S VT]

i have exactly the same problem as well! before i go poking around under the dash could someone tell me if the airbags will go off i i start taking the dash apart ? i have dual airbags by the way
cheers guys

[shiften gears]

just pull the airbag fuse out or disconnect the battery just to be on the safe side

[bradcad]

No the airbags wont go off as they are nowhere near where you are looking, however to be safe as mentioned remove the airbag fuse. I have pulled almost the entire dash apart chasing the same problem. As best as I can, tested the one way valve, checked and even bypassed the valve body, the vaccuum ball, and bypassed the one way valve. I have run a direct line from the intake manifold to the actuators, and the vaccuum appears not enough to open them (ie face actuator has the green and white lines. bypassing all and connecting the white line to the manifold the face vents work, but demister vents still stay on somewhat. Connect to the pink line for the feet actuator and no result at all.) The system appears to hold vaccuum well. I thought it sounded like a hiss at the vaccuum ball, but bypassing it shows no different result.

This started out with a slight change to the demister under heavy acceleration to now changing with slight acceleration, and no feet at all. Vaccuum 'feels' strong through the line. I have pushed a wire through the manifold connection to ensure it is clear.

I have looked previously and cannot find intake manifold leaks. There are also no unusual noises around the manifold. The engine runs well with slight intermittent miss and hesitates off the line. I have been told by various mechanics (way back, when this first started) that there are no vaccuum leaks- for whatever that is worth.

If I cannot figure this out tomorrow, it is going back together the way it is

[Steven M]

Malus, I haven't got around to looking at it any further but I did put a brand new unit from holden and it did not help my problem, so i am guessing it is a vacumm somewhere in behind the dash but who knows where?

[JAM3S VT]

hey guys thought i would just post in this thread as it saves starting a new one. i have the same problem where the a/c changes to demist. I also had a high pitch noise which i figured out was the actuators as the seals were stuffed i put brand new items in and this fixed it but i still have the demist problem. i see you guys are talkin about the soleniod sellector, vacuum tank and the non return valve on the plenum could someone give me some more info on this ie where they are located and how do i no if they are stuffed?
any feedback would be great thanks guys.

[kego]

there are 3 little buttons on the climate control. turn them off and go for a drive.1 of the buttons will make it do what you are describing,its a standard feature because if you start the car in the morning and you let it run for 5 to 10min before you get in the car and want the heater or the air con on so its cold or hot when you get in.one of the little buttons will come on and it will clear the windscreen,same if you are at a constant speed for to long or idling to long.nothing is wrong with your car.hope this helps matthew

[Steven M]

Has anyone ever fixed this problem coz its really annoying me with these hot days!!!! I changed the solenoid thing but still hasn't fixed the prob and also replaced the one way valve under the bonnet on the plenum but still no good, i must have a vacumm leak but I don't know where coz i can't here anything

[jsgvup]

hey man in reply to the antenna issue, do u have an aftermarket headunit, or the fancy eurovox?