Hi all - long time reader, first time poster...

I have a 2002 MCS that has experienced a gradual decline in AC performance. By gradual I mean that we didn't notice, over a period of months, until this past summer how the cold air was now merely cool... It was blowing 60deg.

I checked the coolant levels, and they were low, filled it up with a can to the correct pressure - still blowing at 60deg.

Took it to my local independent garage (general, not mini specialist) who checked the system and found no leaks and the system was in working order. Yet it still blew 60deg... He suggested it may be struggling in the midday Houston sun (108deg on the asphalt) but trying it at night it still blew 60deg (that sounded like BS anyway). They also flushed the coolant with no appreciable change (in fact it seems now to blow 65deg). No change also whether driving at 50mph or standing still on my drive.

Upon reading the forums I see that some of the main AC problems are stage 1 fan resistor causing it to not engage and the AC compressor clutch failing. I'm due to take the car in to a more specialised MINI shop, but would like to get the opinions of more knowledgeable people than I on what the main problem is likely to be.

I should mention that the car has experienced four brutal Texas summers (was in California prior) and in all likelihood is probably on the OEM equipment. Am I looking at replacing the fan and condenser as a first stage fix, or should I prepare myself for a full compressor replacement?

Any opinions would be very helpful

 

Have you changed your cabin air filter? If not, try that as if it’s clogged, your A/C will be weak.

///Rich

 

Thanks. Actually, I did just change it. The replacement was BMW OEM in yellow/green box (don't remember the brand off the top of my head), but not identical to the OEM I took out, which had black plastic sides.

Having said that, the blower is working fine - i.e. I have strong airflow into the cabin. The problem is that the air coming in is lukewarm. It doesn't seem like the cabin air filter would significantly affect the temperature - or am I wrong??

 

Yes. I have and others have experienced that clogged cabin filters limit flow enough to impede cooling. But if you changed it, that can’t be your problem.

And if the system checks out full with no leaks.....

That will require and expert I am afraid.

Rich

 

Would running the A/C without the air filter (not while driving) be an appropriate test to see if the filter is impeding the flow enough to warm it?

 

So I tried running it tonight running with a new air filter, the old air filter and without an air filter... all the same. Blowing 72deg in an 88deg ambient environment. This was after a 30min journey in traffic (which by the end of it was blowing ~60deg).

While testing it on the drive all I heard was what I assume is the second stage fan speed: i.e. loud

Any other ideas? If it's running hot but the fan is engaging am I correct in assuming it's not the fan?

Likewise if the compressor is engaging I'm assuming it isn't the compressor clutch? Or could the compressor still run with a bad clutch?

 

I am in your situation with a 2004 MCS and 127K. Everything works except it doesn't cool. Spent $200 at the dealer after which they told me that the compressor has internal damage, i.e., it engages but no longer compresses. They want $1500 to replace the compressor.

 

Thanks JAB 67. That's helped steel myself for my visit to the shop. I will take it in today and see what happens...

 

Do you know if your low speed fan is working?
Presumed failure mode: Low speed fan dies, AC compressor overheats (low speed is on whenever the compressor is), AC compressor dies.
That's how it seemed to work in my case.
Independent shop wanted $1,100-1,200. Did it myself with the 'Rudy Method' which doesn't require 'service mode' (aka removing front of car.) I think I got out for <$400.

 

Eric - do you have a link for the Rudy method? Missed that one in my trawl of the forums...

Bearing in mind my experience of working with cars is effectively zero, but I am mechanically-minded and enthusiastic - is this something you think an enthusiastic amateur could achieve in a weekend?

 

Well - got it back from the independent MINI shop here in Houston. They said it was undercharged and no leaks in the system. Very strange seeing as the original (non-MINI) shop here bled the system and replaced the refrigerant last Friday. The MINI did blow cooler on the way home - 50deg on the freeway and 55 sat on the drive, so it does seem like the first shop didn't fill correctly...

Anyway, looks like I can put off a A/C replacement for now. Bad news is that I asked them to look at a rattle which I thought was the timing, but turned out to be the supercharger. Quoted me $2900 to replace!! So that's a whole other story...

Thanks all for your constructive comments