How to check if your A/C is working as designed or you are low on refrigerant

[DuSh]

So this could be finally a shot on the simple and straightforward A/C check to put an end to a long lasting debate about F15 poor A/C performance. Here's a official service repair manual procedure - exactly how it is supposed to be checked by dealer if your A/C unit is top notch or is missing a refrigerant!

You'll need to buy a temperature probe tool on amazon (they are about $20 nowadays: https://www.amazon.com/UEi-Test-Inst...perature+probe) and follow this instructions:

A/C performance test
Observe the following conditions prior to the A/C performance test:

1. Connect diagnosis system. Check of the fault memory (no faults in the fault memory).
2. Attach a thermometer with separate display element to the head restraint. Lay display element outwards out of passenger compartment.
3. Perform the test in a suitable workshop area with an ambient temperature above 18° C.
4. Vehicle temperature should be approximately the same as the ambient temperature in the workshop.
5. Engine must be at operating temperature (does not apply for electric vehicles).
6. ECO PRO mode must not be switched on.
Heat passenger compartment:

”A/C button” is not activated during the heating process
Close all side windows and doors
Set air recirculation function.
Select air distribution mode for footwell and defrosting.
On vehicles with CID: In A/C menu (CID) in Air distribution index tab: select 100 % footwell for driver and front passenger and 100 % defrosting for driver (this applies here to driver and front passenger)
Maximum temperature setting
Maximum blower speed
Start engine (does not apply for electric vehicles)
Cool down passenger compartment:

Switch on air conditioning compressor with "A/C button" at a vehicle interior temperature of 45 °C (measured at the head restraint).

On vehicles with MAX‐AC button:

Activation of MAX‐AC (= maximum cooling power)



On vehicles without MAX‐AC button:

Set maximum cooling power by means of following steps:
Setting minimum temperature
Blower setting maximum
Stratification maximum cold (4 blue bars)
Only ventilation open
Close remaining flaps (air outlet only from centre fresh air grille, left and right)
After 5 min, measure both ventilation temperatures with a thermometer at the same time (centre, left and right fresh air grille). The measured temperature must be ≤ 16 °C and the difference between right and left may not be greater than 2 °C.

If one or both temperature specifications is not reached drain off heating and air conditioning system. Measure the amount of refrigerant drawn off and compare with the nominal fill amount.

Check whether refrigerant loss is present:

If there is a permissible loss of refrigerant, fill the refrigerant circuit with the nominal fill amount.
If there is an impermissible loss of refrigerant, check the refrigerant circuit for tightness. After rectifying the leak, fill the refrigerant circuit with the nominal fill amount.


Taken from here: https://www.newtis.info/tisv2/a/en/f...check/GbGkqA9N

And this table shows nominal fill amount of refrigerant and it also shows permissible loss depending on number of years have passed since last filling (for most this would be manufacturing date): https://www.newtis.info/tisv2/a/en/f...-check/PjHa2QC

[DuSh]

Simply put - if your cabin temperature is not lowered in 5 minutes from 113F to less than 61F - then Houston we have a problem and you may proceed to dealership and demand a refill.

[DuSh]

Also, I would appreciate if we can ask mods to make this link a sticky: https://www.newtis.info/tisv2/a/en/

It's essentially a repair manual, electric wiring diagrams etc.

This will be helpful for various things, startinf from repairs, torque values, different procedures, technical data/info and up to service maintenance and various diagnostics procedures.

It has not only X5, but all other BMW models as well.

[CatalinP]

I went to the car dealer with every car I owned and checked the refrigerant and oil quantity every 2 years. From all the cars I owned, F15 has lost the smallest amount over time.

[DuSh]

Originally Posted by CatalinP

I went to the car dealer with every car I owned and checked the refrigerant and oil quantity every 2 years. From all the cars I owned, F15 has lost the smallest amount over time.

That's good to hear! I was just wondering if those who have really bad A/C - maybe they can quickly check performance following this procedure and it will be clear if A/C is good or bad. I was just thinking what if there is a batch of X5 who had under-filled refrigerant amount and maybe that's why some of us have really bad A/C while others have perfectly normal A/C (including myself).

[spike5150]

Originally Posted by DuSh

Simply put - if your cabin temperature is not lowered in 5 minutes from 113F to less than 61F - then Houston we have a problem and you may proceed to dealership and demand a refill.

I don’t think you read it quite right: it says after 5 mins the air coming out of the VENTS must be less than 16C, not the cabin temp...

[DuSh]

Originally Posted by spike5150

I don’t think you read it quite right: it says after 5 mins the air coming out of the VENTS must be less than 16C, not the cabin temp...

Thank you for catching that!

I'm in NY, while my car is in AZ, so I can't check, but I'll do it when I get back. It's really easy for us X5 owners: basically on a hot day, close all windows, put MAX A/C on, start timer and in 5 minuts check air temperature coming from vents. Write down initial temperature in cabin and outside too - so we can compare.

The big deal as I see it - is if those of us who have "bad A/C" and good A/C check it and report our temperatures, -we'll be able to solve yet another mystery. If we'll see that air temperature from vents is more or less same - then it will mean that A/C is working as designed and issue is with something else (owners individual sensitivity, too tight cabin insulation or else). If we'll see that indeed temps coming from vents are different - then Bingo! we'll know that it's A/C itself that is causing this.

At least if air vent temps coming out are colder than 61F (16C) after 5 minutes of running - then A/C is working as it should. Then we can move on to other things (like air flow etc. - tho I'm not sure how to easily check air flow).

[6spdcoupe]

Something like this can give an idea of how it is working, although not the temp coming out. I can certainly check that as well though- actually I did and it was less than impressive but don't recall the numbers so I'll have to try again.
https://www.facebook.com/unexpectedc...68324366626513