[MrSweet1991]

Hi All,

Of all the times for the AC not to work it literally started when we got some sun!

Anyway, how do you diagnose the AC issue? The first thing I check was the pulley but it "appears" to be running just fine, however how exactly does the clutch pulley work? Should the outside spin all the time and once the AC is turned on does the centre bit engage and start to spin? Could be well off but I just wanted to know if you can visibly tell if it engages.

Going forward, what else can you check? Got ISTA, INPA and most other stuff.

[Chappers 71]

I would suggest having the system checked for leaks first, if no leaks then a regas.

[MrSweet1991]

Originally Posted by Chappers 71

I would suggest having the system checked for leaks first, if no leaks then a regas.

I can't remember who did the video on YouTube but the chap said the AC is no different to a refrigerator in the sense that it's a closed system and should in theory never need a regas, what's your thoughts on that? I'll probably take it to quick fit as they'll probably check for free.

[Chappers 71]

Originally Posted by MrSweet1991

I can't remember who did the video on YouTube but the chap said the AC is no different to a refrigerator in the sense that it's a closed system and should in theory never need a regas, what's your thoughts on that? I'll probably take it to quick fit as they'll probably check for free.

Yes it's a sealed system & in theory it shouldn't need recharging, a bit like the cooling system but they usually need topping up occasionally, I would assume the same of the aircon system.

Have it checked for leaks & take it from there

[MrSweet1991]

Originally Posted by Chappers 71

Yes it's a sealed system & in theory it shouldn't need recharging, a bit like the cooling system but they usually need topping up occasionally, I would assume the same of the aircon system.

Have it checked for leaks & take it from there

Will do, going to pop to kwik fit tomorrow and will update the thread. Thanks for the replies.

[Silver Streek]

I would have it serviced, and the person doing it will go over the system properly. Kwik fit will just top is up with gas. I would never let them work on my car. My last experience with them was when I had to challenge them as to why they used a tie wrap to hang the rear silencer on my father in-laws car when they fitted a new exhaust. The manager wouldn't give me the time of day and told me there was no issue. Even when I complained to their head office together with photographic proof they just didn't want to know.

A leak test is easy they will evacuate the system and fill it with CO2 and a die that shows up under UV light, any leaks will quickly show up.

There's no point in having it regassed if it has a leak. If you don't use the AC very often the seals can dry out which causes them they leak.

Best thing no to do it to just leave it on all year round, that way the seals are always kept wet and they system will thank you for it.

With my E46 I only used the Aircon periodically and never in winter. I was forever topping the gas up with a Halfords recharge can.

With my E91 I leave it permanently on all year round, helps dry the carpets out in winter when you get in with wet shoes. I've never had any issues with it either, always works well even in last year's really hot days.

[MrSweet1991]

Originally Posted by Silver Streek

I would have it serviced, and the person doing it will go over the system properly. Kwik fit will just top is up with gas. I would never let them work on my car. My last experience with them was when I had to challenge them as to why they used a tie wrap to hang the rear silencer on my father in-laws car when they fitted a new exhaust. The manager wouldn't give me the time of day and told me there was no issue. Even when I complained to their head office together with photographic proof they just didn't want to know.

A leak test is easy they will evacuate the system and fill it with CO2 and a die that shows up under UV light, any leaks will quickly show up.

There's no point in having it regassed if it has a leak. If you don't use the AC very often the seals can dry out which causes them they leak.

Best thing no to do it to just leave it on all year round, that way the seals are always kept wet and they system will thank you for it.

With my E46 I only used the Aircon periodically and never in winter. I was forever topping the gas up with a Halfords recharge can.

With my E91 I leave it permanently on all year round, helps dry the carpets out in winter when you get in with wet shoes. I've never had any issues with it either, always works well even in last year's really hot days.

Hi mate,

I too discourage others to get most things done at kwik fit bar a few exceptions, however I find Kwik Fit great for free diagnosing, the air con being one of them. I personally don't trust any garage which is why I will go well out of my way to do just about anything on my own, the first BMW Specialist agreed with the AA to install a brand new Lucas Alternator under the parts and garage cover only for me to find overspray and then behind the alternator I quickly noticed the same voltage regulator sticker and corrosion inside.. They reconditioned my own alternator with the same rusty pulleys.. I spoke with the AA and send proof as I already worked on the alternator so had pics of the sticker on the voltage regulator.. The garage got a stern word from the AA and then that BMW specialist had the audacity to basically say it was due to me needing the car ASAP (I record all calls and absolutely nothing was said about timescales) I put a voice recorder in the car when it was sent back in and they where saying how I was "crying and wanting a new one" and another chap said "can't you just change the sticker over, oh no we can't do that cause it's got over spray".. And what's sad is I go past there and see M4's and think you have absolutely no idea what your getting into.

Same thing with another BMW specialist, claimed for "Vacuum Pump, recon Brake Booster and some other bits" at £535 but they actually replaced the 3 inch hose just after the vacuum pump for £27. Absolute F'in rogues both of those where using the AA parts and garage cover so only cost me the £35 excess but its still the point that you can't even trust a BMW Specialist lol

[Silver Streek]

MrSweet it's so hard finding a trustworthy garage. I'm the same as you I do everything I can to my car. Luckily I found a local garage that while not the cheapest are honest and do a good job. So I do use them but only for things I can't do myself. Soany stories like yours where garages blatantly rip you off.

I guess like anywhere there are good and bad Kwik Fit centres, sadly the ones near me are not to be trusted.

I think as long as you ask for a leak test, they should be able to track the problem down. Although the system is a closed system the refrigerant does slowly leak out from the seals, this is perfectly normal and one reason why it should be serviced to ensure its working correctly with no damage or wear to the system and that it has the correct level of refrigerant in it.

To check the refrigerant level the system has to be evacuated and then refilled. When the system is refilled it is not filled to a given pressure it is refilled with a specific weight of refrigerant. This is why topping up with a can of refrigerant from Halfords never works as well as a proper recharge.

Reminds me I need to get my air con serviced, I've never had it done on this car a nice I've owned it.

[MrSweet1991]

Originally Posted by Silver Streek

MrSweet it's so hard finding a trustworthy garage. I'm the same as you I do everything I can to my car. Luckily I found a local garage that while not the cheapest are honest and do a good job. So I do use them but only for things I can't do myself. Soany stories like yours where garages blatantly rip you off.

I guess like anywhere there are good and bad Kwik Fit centres, sadly the ones near me are not to be trusted.

I think as long as you ask for a leak test, they should be able to track the problem down. Although the system is a closed system the refrigerant does slowly leak out from the seals, this is perfectly normal and one reason why it should be serviced to ensure its working correctly with no damage or wear to the system and that it has the correct level of refrigerant in it.

To check the refrigerant level the system has to be evacuated and then refilled. When the system is refilled it is not filled to a given pressure it is refilled with a specific weight of refrigerant. This is why topping up with a can of refrigerant from Halfords never works as well as a proper recharge.

Reminds me I need to get my air con serviced, I've never had it done on this car a nice I've owned it.

That good to know about the seals and I can see why you would probably top up afterwards as it would probably take a very long time to go down lol. It also makes me wonder if it was my short few weeks of actually running the car without AC that may have sped up the issue because I honestly usually have it on all the time, I never really notice any MPG drop and with the car never averaging above 18MPG I'm not really bothered about the smaller impacts that AC may do but sure enough after those couple of weeks it just so happens to not work now. I'll update the thread when Kwik Fit tell me what they find

[NickFrance]

18 MPG? Do you live at Silverstone?

Are there any codes related to AC not performing? Or low pressure codes? Mine is also not working, and of course the best time to look into it is when it starts getting very hot.

[MrSweet1991]

Originally Posted by NickFrance

18 MPG? Do you live at Silverstone?

Are there any codes related to AC not performing? Or low pressure codes? Mine is also not working, and of course the best time to look into it is when it starts getting very hot.

Haha, from what I could find over the forums and talking to some people since 2017 is that if you reset the MPG and all you do is town driving which is literally all I do then 18MPG is about right. £20 - 70 miles

Going to Blackpool with a long run of the motorway stuck at 50MPH I got 55/56MPG





Will let you know what I find out about AC, been a little busy last few days and misses the KwikFit appointment for AC diagnoses lol.

[NickFrance]

I poked around in INPA, I do have a code in the Klima module:
9C4B Can't seem to find much info about this yet.

I also saw that in the engine ECU (I think) there is a reading for "Print cooling agent" and mine is sat at 1.0 bar, on a scale of 0-40 bar.

It would be useful if someone with working cold aircon could look up the same reading and show us what it says.

[MrSweet1991]

Originally Posted by NickFrance

I poked around in INPA, I do have a code in the Klima module:
9C4B Can't seem to find much info about this yet.

I also saw that in the engine ECU (I think) there is a reading for "Print cooling agent" and mine is sat at 1.0 bar, on a scale of 0-40 bar.

It would be useful if someone with working cold aircon could look up the same reading and show us what it says.

You know I'm not even sure INPA has those values on mine, as for the fault code do you have ISTA because it would also give you a real time diagnostic procedure to follow?

[Andystobbs]

The field 'print coolant agent' is the correct field but badly translated.

Druck is the German word for pressure, press, print (in the sense of a printing press for example)

1 bar is too low. The vapour pressure of R134a is more likely to be in the 3-4 bar range at current UK temps.

[NickFrance]

Is there a way to check the clutch operation? Either manually for with the engine running to see if it engages.

[MrSweet1991]

Originally Posted by NickFrance

Is there a way to check the clutch operation? Either manually for with the engine running to see if it engages.

I'd also like to know, I checked INPA and assuming the chap a couple of posts above is right then my number was 4 bar I think which was expected. Thing is, when I press AC it makes absolutely no difference to RPM, usually you'd feel the slight engagement so I have a feeling it's the pulley. It's a shame as well because the AC compressor is a different design than the m47 so it's 325/330/335 specific from what I can tell.