Of course I was hoping this little gremlin on my 2011 XKR would just go away. It didn't! It's actually happening more frequently now. The only "work around" that I've found is to turn the AC off and open the windows, or pull over and turn the car off and back on. Neither of these solutions thrill me or my girlfriend! This never happens on startup so far. Only after driving for at least a half an hour.

I've searched for a solution here and found nothing. Hopefully I just missed the solution because of my faulty searching. I sure hope I'm not the only one with this silly problem!

 

I'd be calling my air con guy down to test the air con system , perhaps after 6 yrs it simply needs a re-gas.

 

I believe there is an electronic sensor that senses the A/C unit is on. When I first turned on my A/C in my XKR there was a bit of heat coming thru the vents then the air would turn very cold. Perhaps you have a bad sensor.

 

It is likely that the valve that controls heating core malfunctions and leaks or opens and wrong time. In such cases you have heating and cooling going on at the same time, and heating wins every time.

 

Its one of those alignment of the stars that you have to ignore.
It does so occasionally on mine.
My understanding is that the way the ductwork is done- it unfortunately gets heated its surroundings. Which is no problem when you have the AC on. But when it momentarily cuts off, you are getting the ambient heat.

Test my theory by running the fan only without ac and it might blow warmer than normal air.

 

Have you tried the "sync" temp on the climate control screen.

 

Are you saying that when both passenger and driver temperatures are set to similar temps, the passenger side vents will sometimes blow hot air while the driver side vents are blowing cold air?

Restarting the car will resolve the problem?

 

Yes, that's exactly what I'm saying. My driver and passenger sides are synced, and while merrily driving along with perfect AC, the two passenger side vents start blowing hot air. Not warm, but really hot air! Hot enough that I'm afraid to try closing the passenger vents for fear of melting the plastic duct work! And the driver's vents are still blowing cool air as if nothing else is happening. Lowering the passenger side temperature does nothing. Turning the AC off and back on does nothing. Pulling over and turning the ignition off and restarting seems to fix the problem until it happens again.

 

That is a controller issue. If you are lucky there will be a fault code that can be read with a SDD.

Unless someone here has had this SAME EXACT issue I would start by getting a read on the fault codes. Buy an SDD or have an Indy read it for you. Then you can get a reasonable idea of the problem.