Heat and AC are both schizophrenic

[Rocket50]

I am having an odd issue that I haven't read about here yet. Maybe I missed a post. Tried searching but nothing lines up.

Have had my grenadier since June of 2025. Daily driver. Being in TN, with the changing temps like they have been, the problem has become more apparent.

If it is cold outside, I get heat blowing from every position on the temp dial except the coldest spot. And it isn't adjustable heat. It is scorching hot. To the point when it is in the second to lowest cold setting, 66 degrees, it is uncomfortably hot. I turn it down to the last notch, coldest setting, and it does shift to cold air. But it is freezing outside so I have to turn it back up one notch to scorching. Then when it is hot outside, the exact opposite happens. Blows freezing cold air on every setting except the hottest. I am turning the dial slowly and allowing it time to adjust, but there is really no change.

I dropped it off at the dealer last week and they had it and tested it for 2 days and came up with the fact that it responds just like their other inventory. I had a loaner for two days and I agree. It did the exact same crazy heat and cold response. The dealer said that's just the way it is. Seriously, that's the best you've got. They have a theory though. Because the car was designed in England it has a difficult time handling the temperate climate of TN/USA.

So for me, I have an SUV that I love but I am pretty sure I could go and buy a 2025 cheapest car on the market and the AC and heat would probably work. How can Ineos produce this vehicle and fail so miserably with the heat and AC? Just seems like a stupid aspect to fail so miserably. It is irritating on a daily basis.

The other thing it does when switching from hot to cold to stabilize temps in the cabin is it starts blowing really cold air in the footwell and hot air up top. What kind of crazy engineering is this?

Anybody else having a similar problem? Any ideas on a fix?

 

[scottedb]

I have a brand new 2025 QM and it does the same thing. Sometimes setting it to auto helps but not always. Not sure what to do at the moment.

 

[JackieTreehorn]

2024 Trialmaster does the same. Randomly will run fan of full blast (even when temp is not extreme) . Other times it will seem anemic.
I have no clue what causes this, but something tells me to start at the input dial (seems a bit cheap to me).

Annoying, but I didn't buy this expecting it to be a Lexus (although I know what you will all say..........its a $90k vehicle and even a base model Kia has proper HVAC)
Bottom line is that lots of little quirks of the Grenadier are not optimal and maybe there are fixes at some point, but I have had mine for 16 months and 10,000 miles and aside from the scheduled oil change, I have not been to see the dealer for a single unscheduled service or any downtime and that's a heck of a lot more than I can say for any of the other new Audis, Porsches, GMC Denalis etc I've wasted money on in the past 10-15 years.
I'll deal with quirks as long as they don't leave me questioning reliability.

 

[Rocket50]

2024 Trialmaster does the same. Randomly will run fan of full blast (even when temp is not extreme) . Other times it will seem anemic.
I have no clue what causes this, but something tells me to start at the input dial (seems a bit cheap to me).

Annoying, but I didn't buy this expecting it to be a Lexus (although I know what you will all say..........its a $90k vehicle and even a base model Kia has proper HVAC)
Bottom line is that lots of little quirks of the Grenadier are not optimal and maybe there are fixes at some point, but I have had mine for 16 months and 10,000 miles and aside from the scheduled oil change, I have not been to see the dealer for a single unscheduled service or any downtime and that's a heck of a lot more than I can say for any of the other new Audis, Porsches, GMC Denalis etc I've wasted money on in the past 10-15 years.
I'll deal with quirks as long as they don't leave me questioning reliability.

I didn't buy it expecting it to be a Lexus either. But I really don't think a functional HVAC is an unreasonable expectation in any car in 2025. When the dial says 66 degrees, at least get the temp close. I have been meaning to take my infrared thermometer with me to record temps from the vent at different settings but never think about when heading out. I will set that out right now.

 

[ADVAW8S]

Check to see if both high and low coolant tanks are filled between min and max. If so, then run the bleed process, it's documented in here. If that doesn't work, take it back and ask for new valve system. My understanding is our system is a heat pump not your traditional car system. Could be wrong but thought I heard that we do on the warner fluid change video. Plus, BMW uses heat pumps on their ev and hybrids.

What I know with heat pump in my house, running cold and hot at same time, it will struggle when not in mild temp. I run auto in PNW in winter and the outside temp is between 40 and 60. Anything out of that range, I don't run auto. I run heat or a/c.

Common System Struggles for heat pumps.
Refrigerant Issues: Low refrigerant levels reduce heating/cooling capacity, making the unit work harder.

Reversing Valve Problems: A stuck valve prevents the unit from changing between heating and cooling.

Both of these is what seems to be out issues. The stick valve can be function of auto moving back and forth to quickly.