AC Warm on passenger side

[Purplecty]

It was a humid day today and noticed that the passenger side AC was not really all that cold but the drivers side was cold. I know on my e38 this is usually a heater valve problem but those are a little different with the aux water pump integrated into them. I've read on the x5, this typically is a low gas issue or is this a heater valve issue as well?

[andrewwynn]

My scanner shows both the left/right heater core temps and valve states left and right. A stuck heater valve is a lighter culprit


Sent from my iPhone using Tapatalk Pro

[Purplecty]

Originally Posted by andrewwynn

My scanner shows both the left/right heater core temps and valve states left and right. A stuck heater valve is a lighter culprit


Sent from my iPhone using Tapatalk Pro

Sorry so you are saying a stuck valve in the heater valve?

[haigha]

My experience over 16 years with my e53 is that it's an indication of low refrigerant.

Check my recent post for two ways of checking for that:

https://xoutpost.com/bmw-sav-forums/...-two-ways.html

And the first time I diagnosed it with help from the great people on this forum and my mechanic:

https://xoutpost.com/bmw-sav-forums/...ht-thread.html

(Skip to the end of that thread for the solution.)

[Purplecty]

Originally Posted by haigha

My experience over 16 years with my e53 is that it's an indication of low refrigerant.

Check my recent post for two ways of checking for that:

https://xoutpost.com/bmw-sav-forums/...-two-ways.html

And the first time I diagnosed it with help from the great people on this forum and my mechanic:

https://xoutpost.com/bmw-sav-forums/...ht-thread.html

(Skip to the end of that thread for the solution.)

Thanks for the input! I have a friend who has a shop with one of those expensive AC machines. I will start with having him drain and refill the system properly and report back after...

[haigha]

Check with your friend as to whether you need to evacuate & refill or just recharge it. I've always done the latter. I'm interested to hear what he recommends.

You might want to replace the valves if doing the full service because, from what I've read, they are a common source of slow leaks. They're not that expensive.

[cn90]

- Or get some professional hose clamps that partially shut the heater hoses (don't squeeze it too much).

- Then drive the car and see if AC is better. If it does, then the problem is with the heater valve.

[Purplecty]

I'm doubting it's the heater valve now from the test listed in the linked thread of where the AC should be cold on a colad start and then warmer after the coolant warms up. The AC is always less cool to warm on the passenger side even on a cold start...

[timmyc]

Just to confirm the evacuate and recharge, my daughter's e46 coupe was doing exactly the same thing. Fixed the issue.

[andrewwynn]

That's a smart test. IR thermometer on the downstream hose also.

They make a hose clamp pliers specifically for closing off a hose. Great for changing parts wo draining the coolant.