I've got a 2005 S with about 78k miles and the AC is going goofy. Since I'm well past warranty I was hoping I could resolve this without having to take it into a shop.

The compressor or at least I assume it's the compressor makes a slight whirring sound -kinda like a high pitched cat purr or electric motor sound. It's not the fan. I assume it's the compressor because this only happens when the AC is on - turn off the AC and sound goes away. I never noticed it until about 6 months ago. Or is that my imagination and the AC on all MINIs makes that sound.

The other thing is the cooling is pretty weak. Over the weekend it was absolutely no match for the heat but on a normal day like Monday was, it blew mildly cool air but not cold. I hooked up one of those off the shelf gauges to the low pressure valve and the the reading was within the "normal" range - something like 32 PSI where I believe normal would be 25-35 or thereabouts. Is that right?

Any ideas?

 

Same exact problem on a 2005 MCS here as well...anybody have any idea what this could be?

 

If you're talking about the cooling or lack of, go here https://www.northamericanmotoring.co...d.php?t=136073

As for the whirring sound when the AC runs, I never got that answered but I'm starting to think it was always there but I just never noticed since I don't use the AC a lot and I usually have the radio and other distractions.