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A/C blowing @ different temps from vents..

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heat vent
73K views 86 replies 38 participants last post by  mr_y82 
#1 · (Edited)
I figured that Id get my car ready for summer today and found that my air condition was blowing at different temperatures. The side vents blow colder than the center vents.
I want to see if it was something that i might have missed before I send it to the dealership. Air is set to recirculate, knob is turned to blue, and the a/c button is on.

Does anyone know if could be a door or valve of some kind? I took the cabin air filter assembly out and the small guard/ wall behind the engine and found the box that controls the vents but I dont know what to look for.

Thanks.
 
#59 ·
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!
 
#60 ·
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.
 
#66 ·
:ben:, I have this same problem. After reading this and other posts, there are several causes for this issue. The HCV failed, low freon, or issues with stepper motor(s) inside the dash. Seems to me if you get nice cold AC with the engine cool, the freon charge should be fine. Once the engine gets up to temp, hot coolant flows to the HCV, which should be closed with AC on if working properly. If it is failed it sticks open causing the mixed heat/cool air issue. What still confuses me is the folks who replace the HCV and still have the problem. Do the stepper motors send signals to the HCV? If a stepper motor is bad, will it cause the HCV to stick open?
 
#74 ·
I had similar symptoms before, when i had my temp dial set to the three blue dots and my tempersture set at the at the lowest, my top vents blew out cold air fine. The problem was I kept feeling hot air coming out from gas pedal area. A friend suggested to look over this thread, so I replaced my water valve. Problem solved.

I have not felt as much heat from the foot area for a month or two, but a few days ago, with my climate control set to auto, and my sandals on, I felt warm air coming out from the area that is to the right of the gas pedal. The air coming out was not as hot as before I changed the water valve, but with the temperature and dial set to the coldest, warm air is still coming out from there.

Any thoughts on what the problem is?
 
#75 ·
If you get this figured out, please reply to this thread. I've had that problem for the past 2 or 3 years now. Replaced the water valve - no change. The only way I get cold air is if I don't use the Auto function, but I select the Top and Middle air buttons. The face and top vents will blow cold, but when the car gets hot, the vents by my feet blow hot as hell.

Next step is to remove the dash, however I don't have the time to take the dash out, try and figure out what the broken part is, order the part, wait for it to be delivered, and then put it all back together. I suspect its an actuator motor or a stuck vent... however I can't find individual parts for that on realoem.com. If I even had a guess at the parts it could be, I'd start buying them and replace them when the dash is out. Realoem shows the center vents as one unit. If someone who has done this knows of the individual part numbers that I can order, PLEASE pass that on as I'm so sick of this issue.

Thanks
 
#76 ·
Check your AC levels first

Guys,

If you have not done so already, have your refrigerant levels checked first. It needs to be EXACTLY to spec (its in the Bentley manual). I had mine charged by a shop and it did not work correctly until I took it back, had them hook up the system and dump some of the refrigerant. It was about 2 pounds heavy.
 
#77 ·
My refrigerant levels checked OK.

I also went back and checked realoem and found some actuators (I forgot I had found them years ago)... unfortunately there is no diagram that shows where these go. They're also not cheap - so I'd rather have a diagram that shows the actuators, or a DIY on how to diagnose and replace these before tearing the dash apart. Already got burned on a water valve I didn't need.
 
#86 ·
A member just messaged me asking if I ever got this resolved. I still have the car, and I still have the problem. I'm posting this here in the hopes someone did actually get this fixed and can provide the details as to what the problem/fix is. Below is my reply that had a few more details as to what I attempted:

"Nope. Still have the car, still have the problem. Since that thread, I did end up pulling the dash out and checking out all the actuator and flaps (or so I thought). As far as I could tell, all the actuators I could SEE were working as expected. The only thing I found, and I was thrilled as I thought it must have been the issues, was that one of the two flaps located in the firewall (don't recall which side) was open while the other was closed. It's been so long, so I can't remember if that one was stuck open and never moved, or if it moved opposite the other side. I seem to recall that it was stuck open. So I was able to separate the piece that moves that flap from the actuator that controlled it, changed the AC to heat, so the flaps opened, and then connected it again so both opened and closed at the same time. I suspect the one was stuck open/disconnected from the actuator during the time I had the dealership replace the leaking evaporator coil. I'm guessing they didn't put it back together properly or didn't pay close enough attention to the details. So thinking I had to have fixed it, I closed it all back up, put the dash back in, took it for a test drive, and realized the problem was not fixed. The only other thing is that there were two actuators that were not accessible without taking out the entire plastic AC housing - I believe they were located at the back of the housing, so I didn't actually check those two actuators and associated flaps. I'm GUESSING that's probably the issue, however I seem to remember getting that AC housing out from behind the frame support bars was going to be a huge pain. I'm going to post this back in that thread in the hopes that anyone who had the same problems we do can post what the actual fix was. Please - if you do get this fixed, let me know the details as this is the only issue I have with my car and it makes summer time pure hell."
 
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