AC Issue

[mirob]

Alrighty, need some help with this issue.

I've done quite a bit of research on this but don't have a concrete solution so I wanted to see if anyone here has dealt with this, on this platform or another.

When the AC is on, only the driver side blows cold air. This is true for front and back of vehicle. It's not "hot" air but it's definitely not as cold as the drivers side, not even close.

Possible culprits:

1) Freon - Checked this and the system is full.

2) Heater Control Valve - Already got the part but haven't touched it yet. Apparently the valve seal will leak and allow coolant to flow (when it shouldn't) thus mixing cold and warm air. I was hoping it's this as it would be a fairly easy fix but wouldn't the air be the same on both sides? Does this valve have any control over where warm or cold air is directed?

3) AC Valve - Could the valve that controls what air flows where be stuck/broken? Does this make the most sense? This valve is somewhere in the dash and having to dig it up would be a nightmare, from what I understand.

Any help would be appreciated. I've been putting this off too long but the summer is near and the Texas summer is brutal, especially here in the desert.

Thanks guys.

[Steadyspeed]

I had the same issue. Mine was the heater control valve for the coolant. I have a 2012 X5 35i and it was on the drivers side down on the strut tower wall I think. It took around 15-20 min to change.

I'd start there, I bought a cheap aftermarket part and it lasted about 2 months. So I had to send it back and get a BMW one. No issues since then. I took my original one apart for fun, one of the o-rings on the plunger had a chunk missing out of it and it was all brittle. So, I'm guessing they only last so long before they break down and fail.

My X has 98K miles so go figure.

[mirob]

Originally Posted by Steadyspeed

I had the same issue. Mine was the heater control valve for the coolant. I have a 2012 X5 35i and it was on the drivers side down on the strut tower wall I think. It took around 15-20 min to change.

I'd start there, I bought a cheap aftermarket part and it lasted about 2 months. So I had to send it back and get a BMW one. No issues since then. I took my original one apart for fun, one of the o-rings on the plunger had a chunk missing out of it and it was all brittle. So, I'm guessing they only last so long before they break down and fail.

My X has 98K miles so go figure.

Appreciate the response!

That's what I wanted to hear. I got my part from Amazon, pretty sure it's one of the cheap brand ones as well but I'll give it a shot.

Yeah, mine is in the same place. Did you lose a ton of coolant? If so, how did you bleed the system? I don't know about the 35i but the M doesn't have a bleeder screw. Did you just leave the tank open and let the motor run to get rid of any pockets of air?

Thanks.

P.S.

I should add that the only reason I wasn't so sure about the Heater Control Valve was because, even when the vehicle was cold after sitting all night, the outcome was the same. I figured it would blow cold air if the coolant was cold.

[Steadyspeed]

I used hose clamps to reduce the amount of coolant loss. I think I had to add about 8 oz of coolant when I was done. I just cycled the electric water pump on mine and then topped it off. After a couple days I check it again and it was fine.

I got my cheap one from amazon also. I can't remember what brand, but it was like $89.00

Mine would blow warm/hot air out one side once the vehicle warmed up. The other side was cooler ,but not cold. The valve was letting to much hot coolant past and cycling through the heater core. Once I changed the valve I had ice cold air out both sides again.

When the vehicle was cold and sit over night the air conditioner blew out cold air because the coolant was cold. Once it warmed up so would the vent air.

[mirob]

Originally Posted by Steadyspeed

I used hose clamps to reduce the amount of coolant loss. I think I had to add about 8 oz of coolant when I was done. I just cycled the electric water pump on mine and then topped it off. After a couple days I check it again and it was fine.

I got my cheap one from amazon also. I can't remember what brand, but it was like $89.00

Mine would blow warm/hot air out one side once the vehicle warmed up. The other side was cooler ,but not cold. The valve was letting to much hot coolant past and cycling through the heater core. Once I changed the valve I had ice cold air out both sides again.

When the vehicle was cold and sit over night the air conditioner blew out cold air because the coolant was cold. Once it warmed up so would the vent air.

I was afraid of that. I think I'll start here regardless since it's not too big of a job and if that doesn't resolve my issue I'll move on to option #3.

[mirob]

UPDATE:

Well, went ahead and installed the Heater Control Valve. It was a pain in the ass getting the hoses off, but after a few cuts on my hands, I got it done.

After installing it I bled the system. I took the old one apart to check the seals.They seemed fine. At this point I was worried that my issue was elsewhere.

Drove the vehicle around, AC seemed fine. Stopped to get lunch...after getting back in the vehicle, same issue as before. SOB!

Well, decided to check the freon level again, thinking maybe my old gauge is broken. I really don't want to take the dash apart, if ya'll can't tell. Got an AC Pro 2 lbs. bottle with their gauge. Hooked it up, needle on border of "Low" and "Filled". Same as my other one. I said fuck it and dumped it all in. Needle barely moved 1/5th into the "Filled" area. AC is cold again. I guess low freon was my issue all along. I'll add another lbs. and keep my eye on it.

If you face this issue, make sure your freon level is at least a little into the "Filled" area before you do anything else. Lesson learned.

[heatmizr]

But now you have a cheaper heater control valve installed, which may not last as long as the original?

[mirob]

Originally Posted by heatmizr

But now you have a cheaper heater control valve installed, which may not last as long as the original?

Yup. I kept the seals from the OEM one, so if seals go bad I can switch them out. If it's an electrical issue, I'd have to get a new part again. I don't think these go bad pretty often so I'm keeping my fingers crossed it lasts.