Odd behaviour from air con

[raym]

I have a VZ Berlina with climate control. When the engine is under load eg going up a hill, the airflow will divert from the dash vents to the windscreen demist vents until there is no load on the engine. The effect is loud wind flow noise form the demist vents, no air from dash vents at all until the airflow is again switched back from demist vents.

This happens no matter what the aircon control settings are at, but seems particularly bad when the climate control is set at about the same as the outside temperature - wind up the climate control temp to a few degrees above ambient and the problem goes away.

This has only recentrly started happening Anyone any ideas?

 

[raym]

Just had a search through the forum and found plenty of posts about the same thing so no need to post a reply.

 

[tk55]

Just had a search through the forum and found plenty of posts about the same thing so no need to post a reply.

really? can you be a bit more helpful and suggest what phrase to search for to get all the posts regarding this subject? i have to read through 3 pages and tens of post just to get to this one, thanks.

 

[neet_wagon]

Would it not be to divert the warmer air away from you while under load (the A/C not cooling 100% while the engine is under load)?

My old man has a brand spankers Subaru Liberty that shuts down the A/C when stationary - sucks balls in traffic! Apparently to relieve undue stress on the engine, perhaps its the same deal?

 

[andyman]

there is a vacuum leak some where

 

[evil-matty]

My VZ does the same thing! whenever I start uphill it switches to the window and stops blowing from the front vents. it would be nice if someone here could direct me to some more info as my searches have been fruitless. come on people where is the sense of community and helping each other?

 

[Veriton]

Comon problem, I've fixed a few of them. Your venting system runs off engine vaccum, if that vaccum is lost then everything reverts back to windscreen. There is a small valve usually situated on the passenger side of the fire wall (in the engine bay, not inside the dash), it's half black and half white and is inline with the vaccum source for the dash, this becomes faulty and can cause the issue, it's the most common of them all, however I've had the same issue with loose vaccum ports behind the dash, this small valve *around 1.5-2cm long* is the most common and is cheap as chips from holden.

 

[Burto89]

I also have this same problem! Bloodying anoying the p**s out of me! So Veriton the best bet is to buy the valve from holden and replace? should fix my problem?

I dont know if this is related but i put a twin 2.5" exhuast on and i thought that might have been causing loss of preasure in the engine? what do you think?

 

[Veriton]

I doubt it, I've got extractors and twin 2.5" system as well and I don't have the issue. These small valves are the most common component to fail, but not the only ones, about 95% of the time these are the issues.

 

[VzVzVz]

haha, suck. Good old manual air con is the way to go. Climate control too complicated