Smoke from Air Con Vents

[talljames]

I am getting a light brown vapour/smoke coming out of my Holden 99 VT Acclaim centre air con vents. Here are the clues:

a) After driving for some time (more than 30min on the highway at 110 km/h) light brown smoke starts to come out of the centre console vents. At first slightly, then heavy.
b) The air con is on maximum cold and the weather is humid outside towards a hot day;
c) When the smoke appears the cooling is reduced. I was away on a trip in recent past and the air con just did not produce cold air anymore but in this case there was no smoke. So this suggests a air con problem. - New gas and leak check perhaps.
d) When it happens I turn off the air con and smoke/vapour still comes. Eventually, it stops and then I can turn the air con on again with maximum cool and it works fine again. - Maybe a blocked air con extraction pipe?
e) The air con is a replacement of the original - after market job.
f) I don't use the heater so I am thinking it is not the heater core.

Has anyone had an experience with this light brown smoke/vapour?

 

[dgp]

I would suggest that your heater core has split. Pain in the arse, most of the dash will need to be removed.

 

[ari666]

when was the last time you cleaned out your wiper scuttle/heater fresh air intake?

does it still happen when you select recirculating air?

i dont see how a heater core would blow smoke. heater core would have a visable leak somewhere and possibly overheating of the engine. not smoke.

 

[Husky]

I had a similar experience (Light white/yellow mist, to me smelt like coolant). It was something to do with a switch in the AC freezing up and not shutting off. Cost me $400 for a fix, but the AC guy recognized the problem straight away and fixed it first go, plus after 10 years it was nice to have the AC regassed.

 

[kiwicon]

I have the same problem in my K11 March work hack.. but it only happens on take off's..

worked that out to excessive take off and to much handbrake..

 

[talljames]

1) dgp - Does the heater core always heat up? Even if you have the air con on cold? If it was a heater core split then coolant could leak out and heat up with the vapor having a smell too it. I will check the next time I park to see if there is coolant in the pool of water that appears under the car. I am hoping this is not it.

2) ari666 - where is the wiper scuttle/heater fresh air intake. Is that the part just under the wipers from the outside? We have a lot of trees that shed those horrible small fine stuff that could easily get into the air intakes. (I park my car outside under trees).

3) Thanks Husky - I will have a think about that one.

4) Next time it happens after travelling on the highway for 30min I will pull over and check under the dash and on the ground for coolant. But, in the mean time I will definitely check my coolant level to see if it has gone down (I should have done this a while ago).

 

[dgp]

Talljames, I'm not sure mate.
A few years ago I had the same symptoms as you describe, had it diagnosed by my mechanic and did all the work myself. My mechanic was kind enough to tell me how long and much it would cost.
From memory it took me about 8 hours in the driveway.