A/C blowing @ different temps from vents..

Originally Posted by Necochino

I just discovered the same problem on my 325 cic today. Left side cold air, right side warm air. In addition, I can not turn off the "auto" function, so I'm wondering if something else than low coolant might be the problem. Any ideas out there? I'm considering unplugging the battery for an hour or so to see if that fixes it.

Regarding the AC blowing warmer on the passenger side. Thanks to this forum I already knew the answer: low on freon. A friend mechanic added some (using all the proper tools to check the pressure) and that was it. It is working back as expected !

Regarding the "auto" function, I'm an idiot. I've had the car for four years and had completely forgotten what it meant. It is the function for the windshield, face, feet blowers. It is working perfectly as it should.

Lesson learned. AC blowing warmer on passenger side -> low on freon. Now I hope it won't happen again (soon anyway) which would point to a leak somewhere... bad thing.

Originally Posted by Yellowmann

I just swap out the climate control unit with my friend to see if that would fix the problem. No luck at all since it still causing heat at the feet and cold in the face. The only thing left I can think of are the motors that control the flap under the dash. I also notice that my pusher fan whines when the AC is on. Does anyone know what else I can check before I have to take it to the stealership

Ok I try again swapping out the AC control with Tas since he got same year as mine. This time we confirm its not it cus mine works in his car but his don't work in mine. He also notice that my fan whines very loud and that my dash outside temp was not the right temp. Mine was like 10 degrees hotter then his. Does anyone know if these added info has to do with my AC problem? Anyone else know what I should check out next?

TIA,
Charlie

i had the same problem but my driver side was colder than my passenger side vents. try evac/recharging the system. that did it for me.

Ivanfuzz, How did this work out? Was it an easy fix? I am experiencing same thing. AC works fine when car is cool. Once I've parked and it sits in the sun for a while, I get warm air from center vent and warm-to-cool air from side vents.

BMW is telling me they'll rebuild the entire system for $1600 (charged me $200 for diagnositics and a recharge) because they don't know what's wrong. Took it to another BMW mechanic, he recharged and added to hose ends/clamps, hoping that would fix. Another $150. Problem is that it doesn't "act" up all the time, so nobody can put their finger on it. The heater valve sounds most likely. Not sure why the "geniuses" can't figure that out.

Anyone else have any comments or suggestions?

im having the same problem with mines just earlier, cold air on the driver's side, and warm on the passenger side. and reading the replies, im hoping that it just needs to be recharged.

but, did you guys who had the same problem heard some hissing sound when the blower is on? and when i turn it off, the hissing sound is gone.

problem fixed! just needed a recharge.thanks!

I am new to the forum but have owned my 330d (2000reg) for a couple of years. Just recently, following an inlet manifold removal and heating outlet manifold renewal, my heating system was constantly blowing warm no matter what temperature I had set. I removed the water valve (mine has the additional water heater) and found a piece of plastic preventing the valve from closing. This was removed and the valve appeared to work fine for a few hours at which point the same thing had happened. I removed the valve and this time stripped it down. The source of the plastic bits was the "additional water pump for the auxiliary heater" which had stripped all four vanes of the pump and these were blocking the water valve. I have flushed the system but am assuming that two of the vanes are still circulating so will wait a few days before fitting the new valve just in case the bits are still circulating and might damage the new one!
Hope this might point some people the right way.
Does anybody know whether you can bypass the auxiliary heater and just use a single valve?

Tony

My AC problem has been fix by Sun BMW dealer locally here. Since I had try to trouble shoot most of what I can on my own, the only thing left was let the pro look at it. They were just that, found the problem to be one of my stepper motor went bad out of the 5 in the dash. They took the dash out and also notice that the center control dial didn't turn the flap correctly to give the right air flow. They made adjustment and its all good now just in time for summer temperature.

Charlie

Ive learned working on many E46s.

When you have different outlet temps from each vent its either.
low charge of freon
bad water valve

Most common leaks.
Evaporator
Line from compressor to firewall

Hi, I've been following this forum for years but this is the first time I post. I have an intermittent problem with my AC, which sometimes blows hot air out of the upper left corner of the center vents, along with cold air, while the side vents blow out cool air. If I close the center vents, the side vents will now blow lukewarm air. If I close all upper vents, the footwell will blow out really hot air.

Here's the intermittent part: The AC always work fine in the first drive of the day. It doesn't matter how hot the weather is. Usually the problem occurs when I make multiple driving trips - one stop after another - say when you drive around town running errands. If my car has been parked for more than an hour or two, the problem usually goes away when I drive again. Have taken it to dealership twice. Of course they didn't find anything wrong; no leaking and they recharged the system. The blower control (auto or manual mode) and temperature sensors seem working fine. So I suppose it's not the final stage resistor or sensor issues. And just in case anybody asks, my center vent dial is set to 3 blue dots and my thermostat is set to 68F (and I live in warm climate).

Could it be the water valve or steppar motors? I'd appreciate any input and advice on what to look into. Thanks very much!

Originally Posted by dailydriven

im having the same problem with mines just earlier, cold air on the driver's side, and warm on the passenger side. and reading the replies, im hoping that it just needs to be recharged.

but, did you guys who had the same problem heard some hissing sound when the blower is on? and when i turn it off, the hissing sound is gone.

Hey, did recharging freon solve the hissing sound? I also hear it only when A/C is on and also have the passenger side temp. little bit warmer.

Thanks !

Originally Posted by hshirl

Hi, I've been following this forum for years but this is the first time I post. I have an intermittent problem with my AC, which sometimes blows hot air out of the upper left corner of the center vents, along with cold air, while the side vents blow out cool air. If I close the center vents, the side vents will now blow lukewarm air. If I close all upper vents, the footwell will blow out really hot air.

Here's the intermittent part: The AC always work fine in the first drive of the day. It doesn't matter how hot the weather is. Usually the problem occurs when I make multiple driving trips - one stop after another - say when you drive around town running errands. If my car has been parked for more than an hour or two, the problem usually goes away when I drive again. Have taken it to dealership twice. Of course they didn't find anything wrong; no leaking and they recharged the system. The blower control (auto or manual mode) and temperature sensors seem working fine. So I suppose it's not the final stage resistor or sensor issues. And just in case anybody asks, my center vent dial is set to 3 blue dots and my thermostat is set to 68F (and I live in warm climate).

Could it be the water valve or steppar motors? I'd appreciate any input and advice on what to look into. Thanks very much!

hshirl: I have the EXACT same issue you have. Your description was spot on to what I experience. It's been acting this way for about two years now. This year, my AC didn't start up at all though, so I decided to attack the AC. First thing I did was change the Outside temp sensor (cheap fix). This made no change.

Next my mechanic (who is a friend) vaccumed the freon, added a sealant to the system and then fully charged the system. This brought the AC back alive with kicking cold air. But then I discovered that I was back where I started. It would blow cold, but if I stopped the car for a couple of minutes I would start getting the warm air just as you describe.

My next step is going to be the heater control valve. I'm hoping it's not one of the flap motors or anything like that.

mtyson227, it's good to get to know somebody who's also trying to solve the same mystery problem.

please let me know how it turns out with the heater control valve. I haven't had a chance to do that test that others described by pinching the water line. It doesn't seem easy to reach down to where the pipes are. And I suppose the test has to be done while only when the AC is malfunctioning.

Good luck with your next steps with the heater control valve. I too hope it's not the flap motors inside the dash!

Originally Posted by hshirl

mtyson227, it's good to get to know somebody who's also trying to solve the same mystery problem.

please let me know how it turns out with the heater control valve. I haven't had a chance to do that test that others described by pinching the water line. It doesn't seem easy to reach down to where the pipes are. And I suppose the test has to be done while only when the AC is malfunctioning.

Good luck with your next steps with the heater control valve. I too hope it's not the flap motors inside the dash!

+1 on having this same issue.

What would happen if I bypassed the HVAC? I just called my local dealer for that part, (not in stock)and they said it would take a couple of days.

Nothing yet huh?

im having the same issue... im going to order the valve this weekend from tischer!

lafabritto325ci, I would appreciate it if you can let me know if your new heater valve solves the problem. thanks and good luck with the repair.

thanks. ill post up as soon as i get the part...

I also have a problem with my AC. Seems to blow hot whenever I first and drive the car. After I stop and turn the car off for a while, when I turn it on, AC blows cold again. Does this sound like the water valve? Thinking of just replacing it. I had the system tested and charged up about a month ago. Thanks guys!

Originally Posted by borygoya

I also have a problem with my AC. Seems to blow hot whenever I first and drive the car. After I stop and turn the car off for a while, when I turn it on, AC blows cold again. Does this sound like the water valve? Thinking of just replacing it. I had the system tested and charged up about a month ago. Thanks guys!

If it gets cold at all, no. Sounds like a typical hot car to me. When you start your car, and its super hot inside......roll all of your windows down with your AC on.....while you are driving. This will help remove that stagnant heat quicker inside.

As for water valves.....a failed water valve will typically cause hot air to blow out of the footwell vents or the defrost vents......when the AC is on. The water valve is sprung open, and is powered closed. This is in case of failure during winter, you will still have heat.