HVAC Issues

[Z51L9889]

I picked up my 2024 4BW about 6 weeks ago. When I took delivery, I noticed that the AC was not working. The dealer found the system was slightly low on charge and topped it off. The AC has worked perfectly since then - until today.

My wife and I were out running errands this afternoon (bright sunny day, temps in the low 80s). Everything was fine on the trip to the store. When we left the store for home, my wife started complaining that she was warm and the AC was blowing ambient air. Long story short, we discovered that the air out of the 4 dash vents was all at different temperatures. The left most vent was blowing very cold air, and the temperature out of the vents got progressively warmer from left to right across the dash. The air coming out of the far right vent was ambient, and the two center vents were blowing air with temperatures somewhere in between.

At the time we discovered this, the passenger temp setting was about 5 degrees colder than the driver side setting, but the air out of the 2 driver vents was noticeably cooler. We experimented a bit with the HVAC settings (Sync on/off, different temp settings for driver/passenger, etc.) and found that changing the settings made no difference. I checked the system again about an hour after we got home and found no change.

The fact that one of the vents blows "normal" cold air makes me think this is probably either an issue with the blend door in the blower housing or the HVAC electronics and not the AC circuit itself. I'll call my local dealer on Monday and schedule an appointment to get it checked out.

Has anyone else experienced something like this?

 

[shbox]

Could be something in the blend door system, but just for grins, try running the temp to max hi and low a few times to see if anything changes. Seems I remember my old ATS had occasional temp issues on the passenger side and doing this often made it work again. I realize that this does not mean there might not be an issue, but I always hate taking my car to the dealer and especially when something might be intermittent.

 

[Z51L9889]

Thanks for the tip. I'll try that.

 

[Ty88]

Sounds like a simple, slow, leak in the system. Back to the dealer.

 

[raptor5244]

Same issue on my son's Honda Civic. Passenger vent blows colder than drivers. This is a symptom of being low on refrigerant. If it gets low enough eventually both vents will blow warm. IMO, the system is still leaking refrigerant. They need to do a leak test and find it.

 

[Z51L9889]

The car is at the dealership today being diagnosed. Interestingly enough, there was another gentleman there with a 5V BW. He bought his car last Saturday and had it at the dealer this morning because ... the AC wasn't working.

 

[ernsteeng]

On my second trip to the dealer they created a ticket with Cadillac and had my hvac replaced. The dealer should be able to get you some answers from Cadillac. They answered my ticket quickly and approved the new hvac within hours. Took a couple days for the parts to arrive, but it was relatively quick and painless all things considered.

 

[SIX 40]

This you tubers AC blew in his personal 5 BW while he was filming. Skip to 17:40 if you don't want to watch the whole video:

 

[Z51L9889]

The dealer did a leak test and found nothing. They also reached out to Cadillac's Tech Assistance line for help in troubleshooting, but they still couldn't resolve the issue. Obviously, there has to be a really slow leak somewhere since this has happened twice, but they weren't able to find it. Since the tech told me he did a very thorough check of all the components under hood, I now suspect the leak may be in or around the evaporator. The only way to check that is to pull the dash, and I really don't want to do that unless we have no other choice. For now, we decided to have them charge the system and let me drive it for the next few weeks. They asked that I call them in 3 weeks and let them know the status of the AC so we can decide next steps.

 

[RKS]

I'm sorry to hear about the issue. Hopefully they can get it fixed without taking it apart.

 

[shbox]

The dealer did a leak test and found nothing. They also reached out to Cadillac's Tech Assistance line for help in troubleshooting, but they still couldn't resolve the issue. Obviously, there has to be a really slow leak somewhere since this has happened twice, but they weren't able to find it. Since the tech told me he did a very thorough check of all the components under hood, I now suspect the leak may be in or around the evaporator. The only way to check that is to pull the dash, and I really don't want to do that unless we have no other choice. For now, we decided to have them charge the system and let me drive it for the next few weeks. They asked that I call them in 3 weeks and let them know the status of the AC so we can decide next steps.

Hope they put some dye in it.

 

[Z51L9889]

They did. No sign of leaks at all, and that's what has me a bit nervous. That indicates to me that the leak site is most likely somewhere inside the car, which means that the dash has to come out to find it.