History:
Last year AC stopped blowing cold.
Bought can of R134a, filled system, all good.

Same thing this year, but system is full, air is not cold.
When AC is on there is a strange 'wheezing' sound from the vents.

Any ideas? TIA.

 

You don't get cold air even when you are driving at highway speed?
If you get cold air on highways, check to see if your fan is running when you turn on the A/C

 

Nope, not even at highway speed. The compressor seems to be kicking in, as I feel the drag when I hit the button. It does blow *a little* cold, but not even close to how it used to get. The telltale 'wheezy' sound tells me there's something wrong, but I can't figure out what that might indicate.

 

First off and this is good advice to everyone, make sure the system is running in recirculation mode at all times with the ac on. No ac system can effectively turn 95 deg air with 60 percent humidity into 40 deg dry air.
Sounds like if you have wheezing through the vent you might have a blend door issue. Run the controls around to every vent position and make sure the air is coming out where it is supposed to. Then make sure the system is switching from fresh to recirculated air, this blend door could be stuck inbetween area's also. I've hade a couple of cars make a wheezing down low on the passenger side whenever the compressor is kicked on and it actually is from low refrigerant. Topping off the system cures it believe it or not.
Sounds like your loosing refrigerent and schould install some dye into the system so you can find your leak.

 

I thought I might be losing refrigerant, but a check showed it's still full (maybe overful??) I really irks me that my 23 year old CRX AC worked perfectly, but my 5 year old MINI has issues.
It's the auto AC, and recirc doesn't seem to make a difference. I'm in CA near the coast, so high temp/high humidity really isn't an issue for me. Always good to have AC for trips into the central valley though!

Anyone have experience with the expansion valve or pressure sensor?

 

MY A/C is also blowing out hot air, but here is the thing mine is blowing out hot air EVEN WHEN MY A/C and heat are OFF and most noticably when I turn the A/C on..no cold air..not even a little

Im so confused, the coolant is fine. I did have a new radiator installed about 1 1/2 years ago but the car had way different symptoms at that time.

I hate to admitt it but we can't even be sure the car isn't overheating because our tachometer is bad (it cost $500 for mini dealer to put a new one in and we just had $900 worth of work done to the car and it is completely drivable without a functioning tachometer)
because our tachometer is bad the car's speedometer lights aren't working and the triangle with ! light is always on. However the fuel gage is functioning and the speed, so i assume..let me say it again ASSUME that the temp gage is working..but who knows for sure. All I need is a head gasget blown because we are too cheap to buy a tachometer right now.
ANyone got suggestions?
Thanks so much
Schaars

 

For you, I'd start with a ScanGauge II - that way you can at least see the H20 temp as the OBDII sees it... And at $150, it's cheaper than an OEM MINI solution.
Still trying to figure out my issue without surrendering a week's pay to the MINI dealership...

 

Thanks I will start my investigation !! Mini dealers charge $100 per hour labor so just to find a problem can cost a fortune.

I hope you find a solution, I will keep my eyes open for anything that resembles your issue.

I love my MINI but sometimes I wonder .....

 

I had the same problem with my 02 cooper, it turned out that the housing case for the thermistat had cracked, i had to have the case and thermistat replaced, but now i have cold air again.

 

Thanks so much for the reply..now that you say that..it makes sense..your mini blew out hot air all the time even when the a/c and heat were off but car running?

 

what happened is the car would not blow cold air when the ac was on, when i would turn off the car somtimes the fan on the engine would continue to run. I don't remember if warm air was comming through the vents when the the ac was off. sorry

 

Thanks for your input!! I hope its not the compressor, Ive been reading a lot of post that seem to point to that and the low speed fan..I almost feel like Im going to be forced to get it looked at..which always costs a lot of $$

 

I have read so many posts on this and I cannot seem to figure this out on my sons 2006 Mini Cooper. I noticed the AC was not blowing cold, after reading posts her I check the radiator/ condensor fan and noticed it does not turn on when you turn on the ac (with recirculation on also). I ordered a new fan unit complete with resistor and installed (that was fun) and still nothing. I did notice the fan will come on when the vehicle reaches the operating temp when it is required but not with AC. I then checked all of the fuses and relays under the hood and replaced the 2 fan relays in hopes to correct and still nothing. I saw where this maybe tied to the PS fan and to verify that fuse was not blown (cabin fuse box) and it is not. Very hard to tell if that fan is actually on without jacking up the vehicle.I had it checked and the freon is full per the shop and when you turn on the AC the compressor engages and the blower inside the vehicle is operating normally. Help.......What am I missing here?

 

what are u seeing on the gauges for high and low side?

 

Prevailing wisdom of the time:
Low speed fan dies.
AC compressor overheats from lack of airflow at low speeds.
AC compressor dies.

I replaced the fan first, ended up having to replace the compressor as well.

Low: Comes ON @ 221F and shuts off @ 214F
High: Comes ON @ 234F and reverts to low speed after dropping 7 degrees.
AC and Fan action:
"The cooling fan operates on low speed when the A/C is switched on AND the system pressure reaches 8 bar. The fan switches to high speed should the AC system pressure rise above 18 bar."

If your fan is known good and it doesn't turn on when the AC is on, compressor likely needs to be replaced.

 

Thanks - I have this problem and have been searching all over looking for someone to say this, as it seems to fit my case perfectly. Is there a way for the relative layman (me) to check this out further? I have a fan that works (high per normal, low only if I manually bridge the relay), relays that work, temperature sensor that works normally, etc. Seems my issue is that something (a sensor connected to the compressor system?) is not telling the low speed relay to close.

Thanks!

 

Is your problem just the resistor, or the AC?
There is another thread on the low speed resistor that shows you the resistor and how it generally looks when it fails.
I don't know of a way to check to see if the compressor has failed other than whether it gets cold. Rather than spending $ on diagnostics, I just went for the new compressor.

 

FYI the 1st Gen MINI AC Compressors are ONE component of very high quality construction, they're very strong and built like a German tank. What "breaks" on compressor is the coil and clutch, and these components are available separately on eBay ! One need not even disconnect the hoses to replace, just let it hang via bungee cords to replace the parts. I think I paid $135 for the kit about 7yrs ago, and still running the OEM 2003 PUMP !!! ( I've had two low speed fan resistors go requiring full fan assy replacement - drove for a while 1st time broken too )