[TheMidnightNarwhal]

It's been hot here hitting 34c/93f and when idle at a light the AC can't seem to keep up, I have the inside set to 21c/69f. Even with max AC button. If I start to move it's get better but not the best either when it was 34c.

Is this a usual symptom of just being low on refrigerant or something else? My radiator fan does work.

[bimmermech123]

Gotta ask, are you using the air recirculation function/button while using the AC. If not, try it, you'll probably see an improvement.

[lordnikon]

I find the AC works pretty well for me, even when I set it to 21C. Just make sure the centre knurled wheel is fully on blue (you already knew that).

[TheMidnightNarwhal]

Originally Posted by bimmermech123

Gotta ask, are you using the air recirculation function/button while using the AC. If not, try it, you'll probably see an improvement.

Yeah I actually started doing that recently but it's not that better.

[bimmermech123]

You can try cleaning the AC condenser, it might help, if not take it to an AC shop and get the pressures checked.

[Fredo]

Check the temp of the air coming out of the central vents. I used this to test my car, it's showing 40F when the car is moving. My wife's X3 shows 45F approx.

https://www.amazon.com/dp/B003CL9LMC...roduct_details

[mainbearing]

You have let a shop draw out whatever is in the system and they can tell you if it is slightly low.

I suppose AC is an after thought in Germany, I do find these systems begin to loose effectiveness above 80F (around 27C), which is about as hot as German summers normally get.

In the low 90s F (32C) it should still keep up. Also try in the shade and see if it does better, but the system may be slightly low.

[gbalthrop]

Originally Posted by TheMidnightNarwhal

It's been hot here hitting 34c/93f and when idle at a light the AC can't seem to keep up, I have the inside set to 21c/69f. Even with max AC button. If I start to move it's get better but not the best either when it was 34c. Is this a usual symptom of just being low on refrigerant or something else? My radiator fan does work.

If you have either INPA or ISTA, or a Scan Tool that can read Live Data in the IHKA (Climate Control) Module, you can determine WHY your A/C system is NOT performing properly.

Any of those CAN show you High Side Pressure with A/C Compressor Valve activated & compressor pumping R-134a/ R12a or whatever your refrigerant is. It can also show you Evaporator Temp which is the critical value for determining refrigeration function, MUCH better than vent discharge Temp. It CAN also show you Vent Temps for Facia Vents & Footwell Vents, along with Ambient (outside) Temp and Passenger Compartment Temp.

INPA/ISTA can also show you "Flap Positions" to make sure air that is being cooled by refrigeration system is NOT being sent through Heater Core and warmed.

If you can report three values, we can tell you if it needs some Refrigerant added:
1) Refrigerant Pressure (high side pressure) when engine/compressor has run for ~ 2 minutes. Should be in 13 bar/ 190 PSI range.
2) Evaporator Temp after system runs 2 minutes. Should be in 5C range.
3) Ambient Temp (per Outside Temp Sensor) at time other values recorded.
4) If you have Manifold Gauge Set, or Can Tap with Gauge, you can add the Low Pressure Side (smaller quick connect cap, close to firewall) value taken at about same time with system running (Optional).

Does your system currently have R-134a or R12a in it? In US, we can still get R-134a in 12 Oz. cans ($10 Walmart) which can be attached to Manifold Gauge set ($35 Amazon), to add Refrigerant using R-134a Temp/Pressure Chart:
https://www.rechargeac.com/how-to/ac...ressure-chart/

You can SAFELY (IF you think about what you are doing ;-) add refrigerant to LOW SIDE SLOWLY, controlling charge rate with Gauge valve, and can tap valve. STOP adding refrigerant when High Side Temp begins to reach proper range. Close Low Side gauge valve and check vent discharge Temp.
NEVER OPEN HIGH SIDE GAUGE VALVE. If you've NEVER used manifold gauges before, ask questions & make sure you understand HOW the Valves at each gauge work, connecting to Center Hose when open. Don't be afraid to ASK QUESTIONS. WEAR GOGGLES when handling/ working with Refrigerant.

BTW, Temp forecast for Munich is 95F Saturday.
George

[Geo_335]

Had this issue and replacing the cabin air filters solved it for me, so I would start there if you haven't already.

[marvinstockman]

First, when the car is moving, the increased air flowing thru the condensor is better able to remove 'condensor heat', and the AC works better.

Second, to remove any variables, such as hot and cold air mixing, set your interior temps to the lowest, and see what happens.

Third, if I had to take a WAG your problem, it is just that you're a little low on R134. Just do what George says, or have a shop do an evac and refill.

Finally, all systems lose R134 over time and will need to be topped up or refilled

[TheMidnightNarwhal]

It's been a while since I did my post but just wanted to update. I kinda gave up on fixing this issue at first since in Canada you cannot buy anymore DIY refill cans with r134a, you can only buy the new refrigerant which is only compatible with the system but you still need to empty out the old stuff first. Problem with that is I need to go to a certified shop. And at that point, might as well just ask them to top up my 134a but then they all told me they had to do an inspection first so all my quotes were 150$ to 200$ in my currency and sometimes I'm cheap as hell when it comes to something I could do myself with a bit more time. But hey last week I ordered a good deal on some sleeping bags and I'm going to the US to cross border pick up (could only ship to US) so I'll have a chance to bring back a can of r134a from Walmart and refill if my problem is that.

So onto the issue... I did the AC test as stated in ISTA by BMW. They say to heat up the cabin until it is around 45c at the headrest and then go on "MAX AC" mode for 5 minutes and measure the vent temperatures. In the middle and left side I had a reading of ~ 19c of air temp and on the right side I was starting to slightly lick 16c. BMW states the temperature must be 16c or less and no more than a 2 degree difference between the vents. If it fails they say to top up system. I also turned my AC on before doing this just to measure the vent temps at idle and with max AC (Max fan lowest temp) I had at most again around 19c. The moment I put my fan speed lower though the vent became to around 9c.


At first wanted to try just cleaning the condenser with some coil cleaner but considering the tests I think the refill if the way to go. I'll report back although recently we did not get the heat we used to have when I made this post, I should still be able to feel it from the vents if it's colder and measure it and see.

[marvinstockman]

Midnight, first cross the border and buy some R134!

Second, you're probably a little low on R134.

Third, when you turn down the fan speed, you're not removing as much 'cold' from the evaporator, and the vent air will have a lower temp, which is also a symptom of a system low on R134.

[marvinstockman]

Also, all my American vehicles had really great AC. All my German and Swedish vehicles had/have marginal AC.

[jbellk75rt]

My 2010 328 keeps me plenty cool in 100+F temps, so something definitely not right with your system.

[krhodes1]

Both of my cars will freeze you out of the car on a 100F day, though the 1-series convertible takes a little longer to get there.

If it isn't icy-cold, something is amiss.

[sgtfury40]

I live in AZ and have 2 e90s, 2e46s. The ACs in those cars are fantastic, even at 110f+ (43c), which we had 54 days of this year. Sounds like you need a top off.

[mecheng77]

You should be getting much lower temps, like around 5-10c

Ppl that complain about their ac system
Are usually low on Freon. BMW ac systems work well but they slowly leak Freon from gods know where. I find Japanese cars are less likely to leak

[TheMidnightNarwhal]

Alright got a can of AC pro and charged up my car the other day and today it was pretty hot at 27c/80f and my car was able to blow cold air on max AC at idle. It was definitely low. I guess I'll see if I have some kind of slow leak in the future.