mist from air con vent

[dirtslinger]

hi all
i was driving this morning with the air con on bit of a warm day here in adelaide when after about 30 mins driving a mist come out of the drivers side vent and not out of any of the others yes they where open .
i turned the aircon off straight away and left it off till i got home then turned it back on in the driveway aircon seems to be getting cold but i could not replicate to get the mist to appear again .
im really hoping this is not a evaperoter problem under the dash and if so how hard are they to pull out is it a whole dash out job .

cheers dean

[richardpalinkas]

this problem happens in the work van, usually the mist is very cold

[bcw61]

I am also in Adelaide, and have noted that the last few days have been unseasonably humid - even in the mornings.

I would suggest that all you are seeing, is atmospheric water vapour that is condensing because of the humid air passing though the cold evaporator. A little disconcerting at first (looks a bit like smoke), but nothing to worry about.

You should see the interior condensation from an aircraft in the tropics with the air conditioning on full cold. It sometimes looks like dense smoke is pouring out of the air con outlets, and can actually make things hard to see inside. Exactly the same thing that you are getting, but on a much smaller scale of course.

[abg]

Seconding atmospheric moisture condensing due to the temperature drop. I had it happen once, scared the crap out of me, thought there was a fire for a second.

[richardpalinkas]

haha, when it happened to me i thought it was exhaust gasses comming through the aircon somehow, only because the van was gas lol. stupid me

[dirtslinger]

thanks for the replys guys i feel some what reassured
had air con cars for yrs but first time Ive seen this . drove the car around a fair bit today with no issues and air con going so all is good . when it happened all i could see was dollar signs lol

cheers dean

[VZ_commo91]

I'm pretty sure its just the aircon defrosting its self, as in it doing it, cause condensation to come through the vent. Nothing major. Not even a problem for that matter.

[gerrypro]

I too have had the same problem. Coming home last night it was so bad that it obscured vision. Are you sure it is atmospheric condensation. Today I had to add 1.5 litres of coolant. Maybe the heater core is weeping?????
Cheers Gerry

[VZ_commo91]

If it's muggy outside, while its on, It will make condensation. It forms where my taps are the control air speed, temp and direction.
You may have a leak in your cooling system somewhere, But will not be the cooler core leaking making this mist. Mine does it too. If fact every car that has had aircon that was friggen cold has done this. All the way back to my parents VK commodore. I used to say the air con was on fire :P

[danieLOL]

this happened to me last week and i shat my pants

[VZ_commo91]

Wow I had no idea people didn't know that they do this... Perhaps they modified newer cars to not do this, But the VZ just so happens to do so.
There is nothing bad about it, Or nothing to worry about.

[slidways]

yeah our fleet of hyundai do this. I had about 20 calls the other day from staff shiting them selfs lol

[gerrypro]

Remove the plenum chamber covers, cleaned the leaf trap gauze and flushed out the heater box with a slow and steady stream of water. End of problem.
Cheers Gerry.

[VZ_commo91]

What problem ? There is no problem, it cannot be fixed... It all depends on the out side conditions while your air con is on. Its just condensation when it goes into defrost. Its like trying to stop fog... Notice that fog is only some nights when its cold over water ? Thats all you are seeing, except out of the air vents from the cooler core.

[gerrypro]

Remove the plenum chamber covers, cleaned the leaf trap gauze and flushed out the heater box with a slow and steady stream of water. End of problem.
Cheers Gerry.

Seemed OK for a while but then the misting came back with a vengeance. Was so bad I could not see where I was going. Out came the dash, the heater box and sure enough the core was leaking at the O ring seal plate. Two days work, new heater core and and re-gas the aircon, and hopefully all will be well. At least I got rid of the horrible old coolant smell from the ducts. Also took the opportunity to replace two small pea bulbs in the Climate control Panel. Not cheap at $8.5 each when you consider they are smaller than a 5 cent coin.
Cheers Gerry

[CRUSTIN]

Didn't you listen to commo? Hes right, ive done an automotive aircon course, mist means you have good aircon.
So stop having a sook over this haunted mist.

[azazeldeath]

I have had the same thing happen to me alot, infact its almost a 50-50 chance of it happening atleast once a day during the wet season. I paid mechanics hundreds to try fix it, and eventually I spoke to some backyard mechanic that I know, and he said the exact same thing as you guys. Though by that point I had stopped really caring, the aircon still worked fine, I wasnt dying of some gas inhalation.

All it is, is harmless water vapor.

[VZ_commo91]

Wooow... I don't even know what to write to this anymore.

Go open your fridge, even your freezer.. OH NOES !!!!!!!!!!!!!!!!!!!! MIST IS COMING OUT !!!!!!!!!!!!!!!!!!!!!! CALL THE ####ING AMBULANCE !!!!
Oh wait!!! Stupid me! I don't know how mist forms.

[CRUSTIN]

Thank you comm, saved my breath. azazeldeath, a mechanic would have probably known that the "mist" is normal, but because they like making money, they never tell you. That's where common sense comes in, sometimes it saves you a lot of money.

[Danoz]

The steam is actually the cold air meeting the hot air... The more mist there is the better your aircon is working. STOP WORRYING!

[CRUSTIN]

...I'm not worrying, we were just laughing at the people who were.

[gerrypro]

Seemed OK for a while but then the misting came back with a vengeance. Was so bad I could not see where I was going. Out came the dash, the heater box and sure enough the core was leaking at the O ring seal plate. Two days work, new heater core and and re-gas the aircon, and hopefully all will be well. At least I got rid of the horrible old coolant smell from the ducts. Also took the opportunity to replace two small pea bulbs in the Climate control Panel. Not cheap at $8.5 each when you consider they are smaller than a 5 cent coin.
Cheers Gerry

Now everything is back how it should be. No more misting. Works like a charm.
I would not mind betting that a few of you people out there have the seals of your heater core leaking. They are a bad design and prone to corrosion of the O ring seats, especially if coolant maintenance has been slack. Ignoring the misting if it is severe is like an ostrich sticking its head in the sand. The problem will not go away.
Cheers Gerry
BTW new cores are available that have welded inlet and outlet pipes. Much better design, however the heater casing needs opening up with a file to slide the new unit into place.

[VZ_commo91]

Now everything is back how it should be. No more misting. Works like a charm.
I would not mind betting that a few of you people out there have the seals of your heater core leaking. They are a bad design and prone to corrosion of the O ring seats, especially if coolant maintenance has been slack. Ignoring the misting if it is severe is like an ostrich sticking its head in the sand. The problem will not go away.
Cheers Gerry
BTW new cores are available that have welded inlet and outlet pipes. Much better design, however the heater casing needs opening up with a file to slide the new unit into place.

I think if people used demineralized water with their coolant, it wouldn't corrode... Tap water is EXTREMELY bad for the engine as it corrodes everything that is runs through.

[CRUSTIN]

Never use water of any kind, if the outside temp ever gets under 0c, the water will freeze, and everyone knows that water expands when in freezes, this causes serious damage, possibly a cracked engine block. Ethylene glycol also acts as a mild anti-boil, it will bring the boil point to 105c without pressurisation. Coolant also has an additive in it that prevents cavitation, which will cause pitting on the water jacket. It can even be important what type anti-freeze/anti-boil you use, depending on seals in water pump etc.

Never use water or demineralized water for coolant. Unless in emergency.

[VZ_commo91]

Never use water of any kind, if the outside temp ever gets under 0c, the water will freeze, and everyone knows that water expands when in freezes, this causes serious damage, possibly a cracked engine block. Ethylene glycol also acts as a mild anti-boil, it will bring the boil point to 105c without pressurisation. Coolant also has an additive in it that prevents cavitation, which will cause pitting on the water jacket. It can even be important what type anti-freeze/anti-boil you use, depending on seals in water pump etc.

Never use water or demineralized water for coolant. Unless in emergency.

I have ALWAYS used demineralized water with quality coolant... NEVER had any problems with freezing...

You are meant to use demineralized water with your coolant.

Is that what you are getting at ? I'm not sure I understand your post.