A/C cutting out

[GregD]

My A/C stops blowing cold air when driving at high RPMs for some time. This has happened to me 3 or 4 times in the last year. I'll be driving quickly on a nice curvy road, and after maybe 5 to 10 minutes, the air coming from the vents will be warm. The air is still blowing, but it appears that the compressor has shut off. If I slow down and cruise, after a few minutes the A/C will start blowing cold air again.

I brought my car into the dealer for this problem, and they replaced a resistor, but that didn't fix the problem.

Before I start pestering my dealer's service department, a couple of questions. Is the A/C supposed to work this way? If so, is there some adjustment that can be made so that it either won't shut off quite so quickly, or at least so that it can come back on quicker?

As noted below, my car is 2003 330i with the performance package.

[01silber]

I cant speak for your exact year model, but a rule of thumb is that when a car is accelerating hard the ac does cut off so as not to drag any power from the engine
if you were doing alot of curves and hitting the gas and then letting off and then hitting it again on the next turn, the ac could have kept cycling so often that it started to warm up
also ac comp. cycling is also related to cabin temp and outside temp
if the cabin is at the temp you called for per your dial once the temp is there is will cycle the system as to keep the evap from freezing over, if it is cold or cool outside it will cycle more often due to the low "low side" pressure , the colder it is outside the lower the low side will be and the low side pressure switch will cycle the system
these things combined with the driving type could have caused this

[GregD]

I cant speak for your exact year model, but a rule of thumb is that when a car is accelerating hard the ac does cut off so as not to drag any power from the engine
if you were doing alot of curves and hitting the gas and then letting off and then hitting it again on the next turn, the ac could have kept cycling so often that it started to warm up
also ac comp. cycling is also related to cabin temp and outside temp
if the cabin is at the temp you called for per your dial once the temp is there is will cycle the system as to keep the evap from freezing over, if it is cold or cool outside it will cycle more often due to the low "low side" pressure , the colder it is outside the lower the low side will be and the low side pressure switch will cycle the system
these things combined with the driving type could have caused this

Here's a little more information. I've noticed this primarily on hot days, exterior temperature 85+. The A/C was working correctly and keeping the car cool at the set temperature before starting the faster driving. After starting to drive faster, when the A/C stops blowing cold air, it never starts blowing cold air again until after an extended time cruising at low RPMs and throttle openings, typically 5 minutes plus. The air that the A/C blows into the car when this happens is exactly the same temperature as the outside air. It's pretty annoying to be enjoying a curvy mountain or canyon road, and have the inside of the car just get hotter and hotter and hotter, until I finally decide I'm not having enough fun to compensate for the heat, usually after 15 to 20 minutes, and starting to sweat a bit too much. :thumbdwn:

[The HACK]

I've heard that M roadsters did this. Under full throttle application (pedal to the metal captain!) the AC compressor will shut down resulting in warm air coming from the climate control system when car is driven aggressively.

Didn't know that it's design that way in the E46 too. Then again I don't turn on the AC when I know I'll be driving aggressively so I dunno.