[DomiGijzen]

Hi all,

Me and a few other dutch iX3 driver are facing an issue. After driving for 20-30 minutes the cabin cools down to noticeable colder temps.
My car has been back to the dealer for 4 or 5 times. Parts replaced and an extra by-pass heater is installed according to the after sales. Also several software updates and adjustments including one where BMW head office had to log in to the car.

Sadly, without succes. Some steps extended the warm period in the car. Other steps did not improve or even made it worse.

Have to go back again on Monday. Last few weeks I used a temp logger to to log what's happening. It's visible that the temp is not stable. It keeps heating for about 30 minutes and then starts to cool down. The air coming from the vents is also cold at this moment.

Does this sound familiair to anybody? I've to car for 11 months now and this issue has been addressed in the 3rd week already. I'm loosing confidence that this will be fixed and am not willing to keep the car like this for another 3 years.

[stefan9107]

Not sure if it's the same issue as mine or not...

It depends on the temperature I set, but if I set it to 22'C for example, it'll warm up nicely for a good 20-30 minutes and then suddenly start pumping out colder air. It doesn't feel like its A/C levels of cold, but it definitely isn't warm anymore. The way I get around it is by just upping the temperature to 23 or 24'C and it goes back to warm.

My assumption was always that when the car reaches the set temperature, rather than maintaining a warm supply of air or just shutting down the air in altogether, it just stops heating. I've always viewed it as an annoyance and a qwerk of the car rather than an actual fault though. I vaguely remember there being a lot of talk about it on the ix3 facebook pages about a year ago when everyone started taking delivery.

There is a thread about it here:

https://x3.xbimmers.com/forums/showthread.php?t=1972278

[DomiGijzen]

Exactly the same!

The thread is indeed also similar.

I also put the temp 1-2 degrees warmer to have the heating start again. but sadly the, it also gets too hot in the car.

[Zerouali]

Yep, same for me, 2022 car

[iX3_M_Sport]

Noticed as well cold air blowing in (2023 car), but driving mainly at Eco mode.
DomiGijzen Does this occur also when your driving in Comfort mode?
I can imagine this is happening in Eco mode to save battery and all battery saving functions.

@User Manual (Dutch)
Eco mode
In de rijmodus ECO PRO vindt stroombesparend verbruik plaats.
De motorregeling en comfortfuncties, zoals het vermogen van de airconditioning, worden aan- gepast.

[Supa Koopa]

Mine does it regardless of the driving mode. In fact I think it is worse in comfort. It's quite annoying to be honest.

[Andras6800]

An interesting logical reasoning popped up with a FB group made for iX3 owners.
"In my opinion this issue is a "normal" physical phenomenon of most heat pump equipped cars:
An active heat pump is constantly extracting energy (heat) from the outside air in order to save energy during cold weather periods. After a certain period of operation time the condenser which extracts energy from the outside air gets frozen itself.
If so it will loose its ability to extract warm air. If that's the case the condenser has be actively defrosted using inversion of the air direction using warm air from within the car's interior for a few minutes.
During that time the amount of warm air blown to the driver's cabin is reduced or interrupted.
As far as I know the car tries to bridge the gap in a limited way using a battery powered heating element. During that period the amount of warm air blown to the cabin may be reduced.
Heat pumps installed in houses have this issue, too. Most owners normally won't notice regular short interruptions of heat delivered to the house because floor heating normally is quite lazy in operation."

To be honest, this seems to be reasonable for me. Does anyone have experience with other EV brands regarding this "issue"?
I am using AC for heating at home, and I can confirm, time to time it is going to defrost mode. Depending on external conditions. Within this short period of time, the AC does not blow warm air. The blow direction automatically set to max upside position and low cold airflow noticeable nearby.

[Mogwai888]

I get this too frustratingly.

My workaround is to start at a lower temp when cold. I have it set at 18.5c which seems warm enough to warm cabin / defrost and then when it starts cooling I up it to 20c. Oddly when it then gets cool again I up it again but then 20.5c becomes too warm.

Either way kinda sucks that it can’t keep to a constant temp as after all isn’t that the job of climate control?

[Andras6800]

Originally Posted by Mogwai888

I get this too frustratingly.

My workaround is to start at a lower temp when cold. I have it set at 18.5c which seems warm enough to warm cabin / defrost and then when it starts cooling I up it to 20c. Oddly when it then gets cool again I up it again but then 20.5c becomes too warm.

Either way kinda sucks that it can’t keep to a constant temp as after all isn’t that the job of climate control?

It is, but you cannot overrule physics. Possibly the situation could be improved by extra ohmic heating addition to defrost the outside heat exchanger.

[Supa Koopa]

It wouldn't be too bad if it was smart enough to just turn the bloody fans off while it did what it needs to, rather than having a nice warm car and then start pumping cold air through the vents. Surely that's not too demanding.

[Andras6800]

Originally Posted by Supa Koopa

It wouldn't be too bad if it was smart enough to just turn the bloody fans off while it did what it needs to, rather than having a nice warm car and then start pumping cold air through the vents. Surely that's not too demanding.

You are right, It shall be smart enough to reduce the air blow rate and direction to the foot.. or anywhere else where it is not so much noticeable. But for defrosting there is also warm air movement needed at inside part of the heat exchanger. De heat stored by inside heat exchanger not enough to defrost the outside part. Therefore heat needed from passenger cabin also.

This is how Split AC works at households. During defrost, de heat pumping detraction switched to opposite for a few minutes.

What I do not know, at iX3, does the heating returning after defrosting? or there is a bug and this effect not caused by defrosting heat pump. What is the case at other dealers?