Radiator Fan Intermittent

Hi Guys,

I was standing in front of my car today while it was running (normal operating temperature) adjusting the headlights and I noticed that my fan keep "flickering" on and off. Spinning for a few seconds and turning off, back and off etc.

I have no overheating issues and no check engine light...is this normal behavior for the fan?

The aux fan in the front? Might be a good time to change your lower radiator hose sensor.

Was the A/C compressor also cycling, like maybe the defrost was on?

The A/C pressure is one of the variables the DME uses to calculate when to turn the fan on.
If the compressor ran long enough to raise the A/C pressure, it may kick on the fan, then if the compressor shuts off the pressure drops and the fan also stops.

I went out to take a video...


https://www.dropbox.com/s/6s1s4uoj4e...6_102927.mp4?m

Originally Posted by shanneba

Was the A/C compressor also cycling, like maybe the defrost was on?

The A/C pressure is one of the variables the DME uses to calculate when to turn the fan on.
If the compressor ran long enough to raise the A/C pressure, it may kick on the fan, then if the compressor shuts off the pressure drops and the fan also stops.

A/C is not on

Go to the hidden OBC menu and find out what the coolant temp is when the fan is doing that.

might be time to replace the aux fan. symptoms of it going bad. turn the a/c on and see if it operates normaly.
it should spin at low speeds when first turned on, its a self check mode it does when you first start the car.
and where your from, i dont think its warm enough to kick on on its own.

Originally Posted by Solidjake

Go to the hidden OBC menu and find out what the coolant temp is when the fan is doing that.

I would love to, how do I get there?

Originally Posted by azshorty

might be time to replace the aux fan. symptoms of it going bad. turn the a/c on and see if it operates normaly.
it should spin at low speeds when first turned on, its a self check mode it does when you first start the car.
and where your from, i dont think its warm enough to kick on on its own.

Vancouver...It's about 39F outside right now. I have been running this car since June when it was 86F out. Come to think of it, I remember the fan doing the same thing the day I bought it.

With the A/C on, she spins and doesn't stop. Turned off the A/C, and back to normal behavior.

Originally Posted by fastsoup

I would love to, how do I get there?

19, then 7.0


http://www.bimmerfest.com/wiki/index...uter_Functions

Originally Posted by Solidjake

19, then 7.0


http://www.bimmerfest.com/wiki/index...uter_Functions

??? Let's try that again, for a guy who has never accessed the On Board Computer

Instructions are in the link. step by step

Hold the left stalk, when it flashes test keep pressing till you hit 19. When it says off, press again and keep going till you hit 7

this will show you how to get to the obc.

Originally Posted by Solidjake

Instructions are in the link. step by step

Hold the left stalk, when it flashes test keep pressing till you hit 19. When it says off, press again and keep going till you hit 7

Sorry Jake, I didn't see the link

Do I do this with the car at normal temp and off or idle?

With the car on. I just want to know at what temp is the fan acting like that.

Originally Posted by Solidjake

With the car on. I just want to know at what temp is the fan acting like that.

With the car on, needle at noon, fan still doing the same thing, it read 0090

i've seen someones auto 330ci do this before. it was strange. it flickers on and off regardless of operating temp. never gets to full/operational speed, just briefly spins for a second then stops. then starts then stops. you can't hear it

At 90C it shouldn't be running imo. Change that lower radiator hose sensor first. If it persists we'll go from there. Sensor is cheap

13621433077

Originally Posted by Solidjake

At 90C it shouldn't be running imo. Change that lower radiator hose sensor first. If it persists we'll go from there. Sensor is cheap

13621433077

Sounds good...I will try and get that done pronto. Thanks a lot Jake!

Originally Posted by E46Mango

i've seen someones auto 330ci do this before. it was strange. it flickers on and off regardless of operating temp. never gets to full/operational speed, just briefly spins for a second then stops. then starts then stops. you can't hear it

Yeah I am going to monitor it and check it when I get home tonight, after a 50km drive and see if it's still doing the same thing. Its fully spinning with the A/C turned on; correct, you cannot hear a thing.