[joewa]

The problem:

My air con fails after a random amount of time, sometimes after 30 minutes, sometimes up to 90 minutes. Recently re-gassed by BMW specialist with the right weight of gas and checked for leaks.

When the air con is on, the compressor clutch is engaged, when it eventually cuts out clutch is disengaged. When working it works well. If I let the car sit (locked) for 10 minutes then restart engine the air con will work again.

I am reluctant to immediately replace the compressor until I have eliminated all other possible (cheaper) causes.

First on the list is the Evaporator Temperature Sensor shown as No. 8 here on realoem http://www.realoem.com/bmw/enUS/show...diagId=64_1454. According to other forums this sensor, when faulty, can cause the aircon to be turned off randomly.

Has anyone replaced this before? It appears to be above the blower which is easy to get at, but I can't see the sensor.

Thanks

[Aragorn30d]

Is the cooling fan running?

Have you tried checking the various modules to see if there are any fault codes?

[joewa]

Hi thanks for the reply.

The main cooling fun is running (radiator fan). The local specialist spent 90 minutes on diagnosis including looking for diagnostics codes and came up empty.