Radiator Fan Problem

mike87 · 04-14-2010, 10:34 PM

recently i've noticed that my fan (the one behind the radiator) comes on intermittently, even when it's not hot out and when the car has NOT been driven hard.

this fan will start up, get up to medium speed, then full blast for a few seconds before slowing down again, and then it will repeat this process continuously. i thought this was weird because i never realized it before.

fuses were checked and none were blown... what could be my problem???

Blind32 · 04-15-2010, 08:33 AM

I'm not sure about this car but on my previous car, one of the fans was the AC fan. It comes on when the AC is on and the car requires more airflow through the radiator & condensor. Hopefully someone else can provide some insight.

mike87 · 04-15-2010, 09:32 AM

Quote:

Originally Posted by Blind32

I'm not sure about this car but on my previous car, one of the fans was the AC fan. It comes on when the AC is on and the car requires more airflow through the radiator & condensor. Hopefully someone else can provide some insight.

yeah i thought this too at first, but i double checked and there is only 1 fan on the z4, the one behind the radiator, no fan in front

mike87 · 04-16-2010, 09:59 AM

i tried it with AC off, same symptoms. when the AC is on, the fan is on continuously drawing air through the AC condenser/radiator.

now as far as i know, there is a coolant temp sensor on the lower radiator hose and another coolant temp sensor on the thermostat. i think my thermostat works perfectly fine... because i'm not getting any symptoms of the sticky or "stuck" thermostat. my car warms up in normal time and i'm not overheating.

i think my coolant temp sensors are okay too, because the coolant temp gauge on my dash is in normal operating order.. right?

there's 1cm of room between my AC condenser and my radiator and there's some leaves and crap stuck in-between there. i think i'm gonna clean it out and do a coolant flush (hasn't been done in a while). hopefully this solves the problem.

please let me know any additional thoughts! much appreciated

04-14-2010, 10:34 PM	#1
mike87 Private First Class 109 Rep 129 Posts Drives: BMW Join Date: Aug 2007 Location: USA iTrader: (0)	Radiator Fan Problem recently i've noticed that my fan (the one behind the radiator) comes on intermittently, even when it's not hot out and when the car has NOT been driven hard. this fan will start up, get up to medium speed, then full blast for a few seconds before slowing down again, and then it will repeat this process continuously. i thought this was weird because i never realized it before. fuses were checked and none were blown... what could be my problem???
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04-15-2010, 08:33 AM	#2
Blind32 Certified Adrenaline Junkie 42 Rep 1,325 Posts Drives: '07 Z4MC Join Date: Sep 2009 Location: Dallas TX iTrader: (2)	I'm not sure about this car but on my previous car, one of the fans was the AC fan. It comes on when the AC is on and the car requires more airflow through the radiator & condensor. Hopefully someone else can provide some insight.
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04-16-2010, 09:59 AM	#4
mike87 Private First Class 109 Rep 129 Posts Drives: BMW Join Date: Aug 2007 Location: USA iTrader: (0)	i tried it with AC off, same symptoms. when the AC is on, the fan is on continuously drawing air through the AC condenser/radiator. now as far as i know, there is a coolant temp sensor on the lower radiator hose and another coolant temp sensor on the thermostat. i think my thermostat works perfectly fine... because i'm not getting any symptoms of the sticky or "stuck" thermostat. my car warms up in normal time and i'm not overheating. i think my coolant temp sensors are okay too, because the coolant temp gauge on my dash is in normal operating order.. right? there's 1cm of room between my AC condenser and my radiator and there's some leaves and crap stuck in-between there. i think i'm gonna clean it out and do a coolant flush (hasn't been done in a while). hopefully this solves the problem. please let me know any additional thoughts! much appreciated
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