Hello all,

I've searched around and have yet to see this particular question addressed, so here goes.

The problem:

My new to me bought in February, 2002 MCS' 6 spd manual with automatic AC doesn't blow cold air when the car is at idle. Strangely, it will if the car is moving and seems to blow cold air. Some readings off of an interdynamics automotive vent thermometer with ambient temperature of 90 degrees F today.

Car running for 5 plus minutes in the parking lot of Advance Auto with MAX AC (LO setting) on, recirculated air on and only the top vents blowing:
90 degrees F.

Drove the car back home from Advance auto w/thermo in vent. This was about a 5 minute trip:

49 degrees F.

At home, I pulled into the driveway and left the engine idling. I popped the hood, and I think I heard the A/C compressor shut off. Sure enough, when I got back into the driver seat, the thermometer was climbing steadily back up to ambient temp.

As the car is new to me and this is the first cooling season I've had to run it, I don't know if this is something that just started happening or the previous owner had problems with (the heater sure worked with now problems).

So, what would cause the A/C compressor to shut off at idle? I don't think that the power steering fan has siezed because I hear it whining at all times, faster when I turn the wheel at slow speeds. (It's always the last thing I hear slowing down when shutting off the car). Also, I don't think it is the fuse as the AC light is on solid green. I appreciate any help from you MINI gurus...

Thank you.

 

The electric fan behind the radiator should be running after the A/C has been on for a few seconds. If not, when the car is not moving there will not be any air moving over the A/C condenser causing the A/C to blow warm air. When the car is moving there is air moving over the A/C condenser and thus cold air.
The condenser is the smaller radiator looking thing in front of the engine radiator.
The A/C system has a pressure switch that will shut the system down when the pressure is to high. When no air is moving through the condenser the pressure climbs quickly because of the heat build up.
It will also shut the system down when the pressure is too low, usually from low freon, to prevent the compressor from being damaged.

Just from what you described I would say that the electric fans on the radiator have a blown fuse, relay, bad wiring, etc...

The exact same thing happened on my Passat and the fan had seized.

Helpfull link.
http://www.familycar.com/classroom/ac1.htm

 

That certainly makes sense and I did neglect to check that fan. I'll take a look at this tonight after work! Hopefully it is something simple like that. As I have the nav system in my MCS, I realize now that I don't have a water temp guage (that's a bit scary!) and instead have a light on the dash. If it is that fan, I bet my water temps are getting higher too. Sounds like I'd better get this sorted out right away for the sake of my engine. Thank you DanSeals!

 

Couldn't wait till after work. On lunchbreak looked at it, sure enough fan wasn't turning on. Checked connectors. Then checked fuses. Turns out the 50 amp cube shaped fuse was completely missing! So, I put one in. Sure enough, the fan works! I wonder if someone took it out on purpose as the fan makes a bit of noise. Or maybe the fuse just fell out. The fusebox cover was missing when I first bought it. (How did I not see that missing fuse?)

Initially it looks like only the high speed fan operation is working, (on for 5 seconds, off for 5 seconds) but it is too soon to tell. At least now I know the engine will be less likely to overheat. Can't wait for the bentley manual to get here...

Thanks for your help Dan.

 

Not sure if the fan is supposed to be on all the time or cycle like you described. Hopefully someone who knows will chime in.

 

The low speed fan should come on almost immediately after turning the A/C on like DanSeals said. The high speed fan should only come on when coolant temps get in the 220F range (and also when the A/C pressure increases above a set limit). I don't have my Bentley manual so I can't find the value but 8 bar seems to come to mind.

 

Yea have a 04 MCS and my ac fan craped the bed and had it replaced. same problems ur stating. NO AC when stopped and after a bit i also noticed that my car began to overheat.

 

Great info, thank you kapps! The fan seems to just come on only at high speed, even from cold start so that would rule out the water temps being high. So that leaves the AC pressure. Hmm, 8 bar. I believe that's 116 psi or thereabouts. That sounds like it would be the high side service port reading, yes? Is that the reading when the AC compressor is running? How would I check this?

 

Yeah, TKooper S, I'll go that route if I have to. Maybe I'll luck out and it just has a bit too much refrigerant in it and will just need to be backed off a bit. From the looks of it that fan shroud won't come out without a fight...