Overheating - Fan not kicking in all the time.
 

So my wife's 2005 X3 keeps overheating from time to time. I have checked the coolant level and even replaced the coolant (yes with BMW coolant 50/50) and bled the system. There are no leaks anywhere. I have changed the thermostat, all the hoses and even the coolant temp sensor. What I have noticed is that when I start the car, sometimes the fan never kicks in and the guage eventually starts to tilt right. I have also replaced the fan with a known good used fan but the problem still persists. Could it be the F AUC Sensor? PLS HELP!!!

Issue resolved... My "known good used fan" is actually now known to be bad. Replaced the fan with a brand new fan and the fan kicks in immediately the car starts.....

which fan r u talking about , because i have the same problem car keeps overheating. is it the AC fan in the front or the inside engine fan?

The problem was with the fan in front of the car, very easy DIY to replace but the fan is expensive, about $500+. That resolved my problem immediately. Good luck.