'02 745Li Air con woes- can anyone help please?? [Archive] - Bimmerfest - BMW Forums

: '02 745Li Air con woes- can anyone help please??

06-13-2012, 11:56 PM
Ho everyone, I have just joined the Site and hoping that someone, somewhere, may be able to help.......

I recently bought myself a 2002 745Li, which- to be blunt- I adore. It has not been without problems though.........
I live in Dubai, and the air con was not blowing much cold air, so i had a garage (that i have used before- and trust) re-gas the system for me.
Freezing cold air for the next 10 hours....then none at all.

So, i took it to another garage who leak tested it, and told me that the evaporator was leaking, so that was changed. Again, after a re-gas, its was fine- until i turned off the engine....then nothing.
I have since taken it to a 'BMW specialist' who ran a diagnostic, and said it was the compressor!!!! So, back to the original garage- who has a 745Li sat doing nothing- and swapped over the compressor.
Again, all through the 4 hour drive that followed, i had perfect cold air. As soon as the engine was turned off- nothing.
Again, back to the specialist yesterday, and again they have told me to change the compressor- even though it was working perfectly UNTIL the car was turned off/re-started.

Being new to the car, i really dont know much about it (yet) can anyone suggest a solution or known fault as to what may be the problem? It surely cant be the compresor- it was working fine in the other 745 until swapped, and worked fine in mine until the car was turned off/re-started. Again, the specialist wants to change the compressor!!!! Is there any known problem- or better- solution to this problem??

Any help would be greatly appreciated- its 44 degrees here most days, and im currently driving 700km a week with no air con!!!

Many thanks in advance.


06-14-2012, 09:56 AM
first thing you need to do is FIND the leak .. now if the compressor is leaking from the seal

sit tight and write that check

if its a hose you can send it to a place like "airmac" and they repair the hose for you better than bmw quality foir pretty much half the cost of a new hose ..


06-16-2012, 12:37 AM
Thanks for that. THe problem that i have is that there are no leaks- the car went to once garage for a test using utra violet dye, and it showed a leak to the evaporator. This was replaced- after a lot of hours labour!- and re- checked and the system is leak free.
Once the work was complete, it blows perfectly cold- right until i either turn on the high level vents in the rear, or turn off the engine.
It was perfectly cold on a four hour drive- perfect. The moment the engine is switched off, it stops working!!!

Given that there are no leaks, and it blows cold, i was hoping there may be a common fault- electrically? Or with a valve or something similar. Again, all parts of the air con system have been replaced- and worse is that i know the compressor is good as it functioned perfectly before it was swapped from one car to the other!

Any other suggestions welcome!!!!

Many thanks for taking the time to read and reply though- appreciated.