2005 BMW 325i HELP!!!

[pammil6801]

Hi! Thank yall for having this forum and hopefully someone can help me before I go insane! I have BMW 325i automatic. It has been overheating or tryin to..at idle the electric fan in front of radiator isn't coming on to cool it off. Works with ac. I've not let it overheat but it's gotten almost to 3/4. I replaced sensor in lower radiator hose twice (boiled both and they seem to be working fine), replaced climate control recirculated air sensor, and replaced electric fan in front of radiator. Took to a private shop owned by a BMW specialist and he plugged up to computer and turned fan on. He told me to replace sensor a third time (he had never seen this before). Called him back and told him it had been replaced again (3rd) time. He told me to check manual fan.....I replaced it and almost all radiator parts when I purchased car 3yrs ago to fix leaks. I replaced manual fan with a europart...I think that is how it's spelled. metal blad water pump....can anyone please tell me where to turn now???? Mechanic said DME is working or he wouldn't have been able to turn on fan with his hand held...Thanks again!