midtowndesi

I have an 06 white xB with about 6200 miles on it...

This happened to me twice already (months interval in between incidences) so I thought it may have just been a fluke... lets see what we come up with..

A few months back, I had the A/C in my car on, and only set to the first notch - the lowest setting. I started smelling something burning so i turned my A/C off and immediately, I noticed a white cloud of smoke come from a couple of the A/C vents.
I opened the hood and everything seemed alright. The white smoke left sort of a residue on the vents but it went away/evaporated within a minute or too. But the smell lingered for a little bit. I then turned the A/C off and nothing happened..

Fast fwd a few months later until now...

I had the same thing just happen and as a precaution, I am taking the box to a friends shop just to check it out... I don't think anything is seriously wrong with the box because this happened
once in maybe. January or February and it hasn't happened since until this morning. I haven't done any mods or anything like that to the box so it's basically a stock box that I have.

If anyone can shed light on what this may be, I'd greatly appreciate it!
- sh00k

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mad-sciontist

**looks for his flashlight** Nope, cant help ya, sorry bro, good luck though!!

xbc

Generally when white smoke comes out of the A/C vents it is a coolant leak from the heater core. It will smell, look like white smoke and leave a residue on the windsheild if it comes through the front vents. Warranty repair!

vintage42

So you have seen white smoke coming from the vents and smelled burning on two different occasions:
1. In the cold NYC winter using the heater.
2. In the hot NYC summer using the AC.

It is not likely related to the heater core because:
1. The heater core is closed in summer unless you are using defrost.
2. A coolant leak would be liquid, not vapor or smoke,
3. Coolant would not make a burning smell.

The smoke and smell could be coming from the fan motor. Pehaps there is an electrical or bearing problem there.

I have seen white vapor from the vents when running the AC very cold on a very hot and humid day (Ohio Valley, 95% humidity). At first it looks like smoke from a fire. This is moisture in the humid air condensing into visible vapor after passing through the evaporator. But this cannot happen in the winter from the heater, and it does not have a burning smell.

xbc

I disagree, it can be the heater core. I have had this happen to me on 2 different occasions in different cars. The leak from the heater core will cause white smoke to come from the vents and leaves a residue you are discribing. Generally it is a sweet smelling odor not burning smell. But you never know what a leaking heater core can burn inside the vents. It is hot liquid.
If it has never happened to you Vintage42 I can see how you wouldn't understand it to be possible. When the heatercore first started leaking in one of my cars I thought my car was on fire because so much smoke came out of my vents when I turned on my A/C one day. There is only a vaccum control gate that seperates the door from the heater core to the A/C vent. The Heater core is only a mini radiator looking part. Easy to leak if it is defective.

Vintage42...You are only 6 years old?

midtowndesi

If this is the case, is this normal? Thank you both (Vintage and xbc) for your input!
- sh00k

vintage42

I had a heater core leak in another car and replaced the core myself. Coolant on that car was admitted to the heater core by a valve. The valve was closed in the summer and opened in the winter by the dashboard heater control. I saw no smoke, just smelled the sweet coolant and saw the leak. The coolant in the heater core is only 200 degrees, while igniting even paper takes 450 degrees, so a coolant leak is not going to burn anything in the car.

If the poster had a heater core leak, and if the xB heater core is always hot, and if the heat is only kept out of the car by a control gate in the duct, then his problem would also require a failure of the control gate, in which case heated air would fill the car. But he did not report that an open heater gate was causing a reduction in the AC temperature.

vintage42

Yes, it is normal and has nothing to do with the car. Perhaps the hot humid Ohio Valley weather you are now having in NYC is the cause of what you see. Vapor from the vents disappears within a foot. Smoke will persist and fill the car. Are you sure that you are seeing and smelling smoke?

xbc

This is all speculation since we can't see the exact problem. With only 6k miles take it to the dealer and they will fix it for free.

midtowndesi

I am going to the dealer for my second oil change so I will definitely be telling them about this issue.

It looked like it was smoke but it may not have been - I am not familiar with anything like this at all... It was more of a mist and didn't fill the car... Immediately when it happened, I shut the car off and the "mist" lingered off - meaning it stopped coming out of the vents... When I started the car again, 2 minutes later, and turned the AC on, nothing like this happened... This is when i first noticed the problem in the winter...

It had a really strong smell to it which, now that i think about it, my not have been a burning smell... but it was definitely strong...

I am going to take it to the dealer and have them look @ it... I'll post what they come up with...
- sh00k

vintage42

If it should be fog, and if the heat and humidity are not right to make fog, the dealer will not see it. If it is fog, there is nothing to fix except the humid heat wave. Let's hope the poster keeps us updated on his visit to the dealer.
Meanwhile, has he tried using his AC again? In the cooler nights of NYC's humid heat wave, the mist might not appear.

midtowndesi

I have not used the AC since this happened... I'll try using it this weekend and will let you guys know the results... hopefully it'll be cooler here... I just walked 2 miles carrying a 20lb box - and it's in the high 90s right now!@#!@#!@#

l0l - I appreciate all of your input though! thank you for the advice!
- sh00k

peteski

Pure and simple - if it had a strong odor, then it is not just condensation mist (from humid air). Condensation would not have had strong odor. Sounds like you do have a real problem.

Unless that was just a "new car smell". ;)

And I agree that when heater core is leaking on xB, it will leak into the air plenum no matter if heat or A/C is on. This heater core circuit doesn not have a cut-off valve. Coolant always circulates through it.

Also, the fan speed selector resistor in in the air plenum. If that was burning, smoke would come out from the vents. So is the motor. But if either of those had a problem, then the smoke would come out in any mode (not just A/C).

vintage42

Midtowndesi does not seem sure that it was smoke. He says "It was more of a mist and didn't fill the car..."

Nor is it clear that it only happens with AC. Midtowndesi said "... this happened once in... January or February and it hasn't happened since until this morning."

New York City is frigid in Jan-Feb so I assumed he was using the heater, but as I re-read his post, he does say he was using the AC in Jan-Feb. But AC in the winter could not make fog any more than the heater would, unless the fog was smoke. But if it was smoke, surely it would have happened again in the 6+ months between Jan-Feb and Aug. Or, if the heater core was leaking Jan-Feb, surely that also would have become a serious problem back in Jan-Feb, with loss of coolant and perhaps liquid inside the car.

peteski

True...

luvmyxb06

I have had this experience too , in fact last week while I was driving on the interstate, I had turned off my AC and opened the windows, then quickly decided to change my mind because of the humidity. I turned back on the AC and white "smoke" came out of the vents. If of course quickly shut it off and dialed my husband, who has been a mecanich for over 15 years. He said that if there is a sweet smell with the smoke, it's freon and comes from the core. If there was no smell and just "smoke" then it is humidity coming from the vents and they should be wet/damp.

I had no smell coming from mine, so it was just humidity. In your case, with a smell like that....I'd refer to the dealer for a quick repair.

TheBlackPearl

what did the dealership say?

jones75254

coolant/heater core problem for sure. had it once on my previous car, sucks.

midtowndesi

Thanks for the information guys... I am going to the dealer this saturday and have my appointment at 7:30am... In addition to my second oil change (I'm at about 6500 miles now), i am going to mention this problem and see what they come up with!

I just hope they dont have me sittin' in their donut and coffee room for like 4 hours =(

The one other issue I just remembered is the fac that the rear bumper keeps "splitting" apart... the point on the rear bumper, like directly beneath the licence plate, always "vibrates apart to the point where i can see the "mounts" that are supposed to secure it... when this happens, i simply push in both parts of the bumper and it's taken care of... until i start driving... lol... i was never hit in the back of my xB or anything like that so this problem has existed since day 1...
- sh00k

Spect2K3

Let us know what happens, i'm having a similar problem with my tC (actually how I found this thread). So let us know the outcome as it progresses