Air Con not cold - Advise required

bigshout · #1 04-10-2010, 06:00 PM

Guy's i've only had my X5 a week and with the weather we have had today noticed the AC wasn't cold. Decided I would take the X5 to have the AC re gassed. the job is all computer driven and no room for engineer error however the engineer I has was very informative and knew what he was doing.

Anyway after 30 minutes the re-gassing was completed but unfortunately the temp did not go down, on the up side they did not charge me as this is their policy if they can't bring the temperature down.

The result are that I don't have a leak, the car was holding 270g gas and 2ml of oil before th regass and the machine inserted 440g gas and 12ml of oil. Unusually the reading given was that the low pressure reading was high at 7 bar and the high pressure reading low at 6 bar.

The AC control in the car operates fine, it blows hot or ambient, controls work as far as I can see. I can't say I've seen the AUX fan operate, now from reading what I can find on this forum I've narrowed down the issue to either the final stage relay, the compressor it's self or the Aux fan. What I'm not in a position to do it purchase these items from BMW to find some of the parts are not needed.

Has anyone any ideas on how the diagnose this issue, ie a step by step guide on what I should be doing to identify what and where to look, I don't even know where to locate the compressor. are there drawings on the internet?

The car is a 2004 4.4i with 62k miles.

bigshout · #2 04-11-2010, 08:02 AM

I've checked to day, when I press the AC button the AUX fan does not spin, the revs do not drop.

I do have one question though, which is the power to the fan out of these two pictures to guage a voltage from?

or

Lastly should there be a cable connected into the other side of the connector seen in the first picture?There are 4 cables in one end and I can feel the other end is a plug type but no cable visable. Could this be my problem?

Lastly where is the AC compressor if I'm facing the engine? Should I be able to see it and the belts?

cat97628 · #3 04-11-2010, 11:10 AM

you may want to pickup a Bently which will give you a better idea of what goes where. You also can try to use the parts diagrams on realoem.com to get the same idea. Sorry could not be of more help.

bigshout · #4 04-12-2010, 11:20 AM

Anyone able to help with my questions?

Repoman · #5 04-12-2010, 12:18 PM

Answer these two questions . . . Is the compressor clutch engaging when your A/C button is pushed? Does the vehicle blow cold air near the end of a short highway trip?

If you compressor clutch is not engaging, the DME will not allow the AUX fan to run. Also, if the AUX fan is out the DME will not allow the compressor clutch to engage. Kind of a catch 22 for diagnosis but easy to figure out.

Answer the above 2 questions and we'll move on to the next step in your diagnosis.

jst2878 · #6 04-12-2010, 12:56 PM

check your fuses?

bigshout · #7 04-12-2010, 05:32 PM

Cheers guys, the first thing I checked was the fuses and there all ok.

Is the compressor clutch engaging when your A/C button is pushed? Does the vehicle blow cold air near the end of a short highway trip?
I guess not, however I don't know where in the enigne bay the AC compressor is located to check, the revs don't drop when the AC button is pressed. The air does not go cold when driving at low or high speed.

Would an independent BMW garage be able to indetify which item is at fault?
Could it be the FSR, the temp controls work fine as does te auto button.

Repoman · #8 04-12-2010, 06:12 PM

The compressor on mine (3.0L) is located on the bottom left side on the front of the engine as you are looking from in front of the car. It will have two metal pipes that convert to rubber hoses connected to it in near vicinity to each other and of course a pulley on the front connected to a belt. The pulley will continuously spin while engine is on but the part inside of the pulley will only spin while A/C button is pushed.

It doesn't sound like it is engaging to me, need to find out if voltage is being supplied to the compressor clutch. If voltage is being supplied, then bad compressor clutch. If no voltage being supplied, probably bad AUX fan. Either one can be $expensive$! The fact that you don't experience a kick-down of engine rpm makes me think it might be AUX fan as you would still hear/feel a kick-down if compressor clutch is bad because that function is handled seperately from the compressor.

My A/C compressor clutch went out before on me and was looking at $500ish for a new compressor just because of that little crappy clutch on the end. I just replaced the clutch only with an aftermarket generic that seemed to be same dimensions and haven't looked back since. $39 by the way was my total cost for that fix.

bigshout · #9 04-13-2010, 07:55 AM

Quote:

Originally Posted by Repoman

The compressor on mine (3.0L) is located on the bottom left side on the front of the engine as you are looking from in front of the car. It will have two metal pipes that convert to rubber hoses connected to it in near vicinity to each other and of course a pulley on the front connected to a belt. The pulley will continuously spin while engine is on but the part inside of the pulley will only spin while A/C button is pushed.

It doesn't sound like it is engaging to me, need to find out if voltage is being supplied to the compressor clutch. If voltage is being supplied, then bad compressor clutch. If no voltage being supplied, probably bad AUX fan. Either one can be $expensive$! The fact that you don't experience a kick-down of engine rpm makes me think it might be AUX fan as you would still hear/feel a kick-down if compressor clutch is bad because that function is handled seperately from the compressor.

My A/C compressor clutch went out before on me and was looking at $500ish for a new compressor just because of that little crappy clutch on the end. I just replaced the clutch only with an aftermarket generic that seemed to be same dimensions and haven't looked back since. $39 by the way was my total cost for that fix.

Could you send me a link or contact for the clutch repair? Also how easy is it to get the AC compressor out? Assuming it's accessed from under the car.

Repoman · #10 04-13-2010, 03:08 PM

Quote:

Originally Posted by bigshout

Could you send me a link or contact for the clutch repair? Also how easy is it to get the AC compressor out? Assuming it's accessed from under the car.

http://www.xoutpost.com/bmw-sav-foru...failure-6.html

http://www.xoutpost.com/bmw-sav-foru...pressor+clutch

The first link is the link I followed to help me with my repair. The second link is my post while doing my repair. These were both on 3.0's I believe.
Getting the AC compressor out is standard for a BMW. First you have to remove everything else under the hood then you can get it out.

I tried to make the swap with the compressor still on the vehicle but did not have enough room. Ended up having to remove it which included cracking open the system and then having to reseal it, vacuum it, leak test it and refill it.

Make sure your diagnosis is correct before you start replacing stuff or you could spend more than what the correct repair would cost. Do a several searches on "ac problems", "compressor coil", etc. and do some reading. That is partially how I figured out my problem. I was all set to order a $450 AUX fan when I was able to properly diagnose that the AUX fan was not the problem.