Air conditioning stops in high temperatures

[Colin]

My aircon (climate control) has always worked well, but in the unusual 30+ degrees temperatures in UK at the moment, it will not work unless the temperature drops below about 25-27 degrees in the morning and evening - exactly what is needed (not!).
When I start the car, the aircon makes the usual 'clunk, but after 30 seconds or 1 minute a quiet 'clunk' happens and the cool air stops. I can switch off and restart with the same thing happening again. Sometimes there is also a short 'squeek' that seems to be under the dashboard/fascia too.
When the air temperature outside drops it works correctly.
Any ideas where I should start to look to fix this problem.

[Peter1]

How old is your car? Ever had an aircon maintenance / refill? I think it could be just not enough coolant in the circuit.

[jacinto]

I agree with peter1... most probably the aircon filter also needs replacement...
my aircon worked fine with 40+ degrees. inside the van we had a refreshing 22º

[akami]

I had that problem on my Alfa 147.
After a service there was too much cooling-stuff inside the system. The system-pressure was too high at high temperature so the security-system switched off the cooling.
The noise you hered ist the cluch (kupplung) of the kompressor.

[DetteK]

Every 2 years the air conditioning serviced! Then there are no problems.

[Peter1]

Originally Posted by DetteK

Every 2 years the air conditioning serviced! Then there are no problems.

Did you never had problems that your aircon worked fine before the service, and gave problems after it?

The price for a service is not much, but that's something what was keeping me of such a service till now (and also the fact that till now I exchanged my cars after max. 3 years).

[FuliHdi]

Originally Posted by Peter1

Did you never had problems that your aircon worked fine before the service, and gave problems after it?

Hi,
I did not, but many friends did, so I service the aircon every 4 years, I just don't feel like openening an aircon that works & cools like a freezer (3+ years old "untouched" aircon tested in Sevilla at 42 deg. C)

[Colin]

Thanks for the useful suggestions about the coolant level and the operation of the compressor clutch. I can't see how other messages about regular maintenance will help but it's fun to read.
I checked the coolant and it's 30psi which is in the correct range so the coolant level is okay. The filter has been changed so it's not that.
Any other ideas about what to look for?

[FuliHdi]

Originally Posted by Colin

Any other ideas about what to look for?

Hi,
I can imagine the reason could be a fault in the temperature sensor or it's wiring, but this shall be hard to trace out

[Peter1]

......... or an electromagnetic valve in the control of the aircon or something - I've read about similar problems (aircon circuit quite filled and under pression, but no cold air blown) on SGAF :: VW Sharan, FORD Galaxy S-MAX, SEAT Alhambra - maybe have a look there (of course it's a different car, but because they have plenty of aircon pbl's, maybe tips can be got there )

EDIT sorry - maybe not possible if you can't read German

[Colin]

I should have followed this up with the solution to the problem. I took the car to the dealer for them to replace the door mirror glass (that they broke when their van hit the door mirror a few days earlier when i booked it for service). They thought the temperature sensor was in the door mirror (strange!?) and confirmed that the temperature sensor circuit was not working correctly. Fixed it and problem solved at no cost!!!.

[FuliHdi]

Don't worry, better late than never . Thanks for your feedback about the solution! Rgds Bor.