[jrice31b]

Hi guys

I have an 09 E90 335i that I am pulling my hair out trying to fix. The radiator fan isn't kicking on at all and the car overheats. So far, I have:

-replaced water temp sensor in cyl head
-replaced the fan relay in the white fuse panel under the hood
-bled coolant system

After I start the car, the fan doesn't come on. If I unplug the harness from the fan itself and plug it back in, the fan comes on at full speed for about 1 minute, then kicks off, and doesn't come back on again until I can see the car getting too hot.

Not sure what else it could be, but I'm running out of ideas. I don't have a scan tool yet but the sensors I replaced I would think could be the culprit, but it still isn't working.

Thanks

[dmckmc]

sounds like the fan will work as you mention you can force it on. are you getting a check engine light? i understand you don't have a way to check codes or history.

I believe the fan will always come on with A/C, that may be another check of the dme control.

you may consider other components such as the water pump or thermostat. water pump bleed can be done in car with no special tools to test water pump function.

history codes will be stored even without check engine light and that could provide direction if you can get the car scanned.

[jrice31b]

Originally Posted by dmckmc

sounds like the fan will work as you mention you can force it on. are you getting a check engine light? i understand you don't have a way to check codes or history.

I believe the fan will always come on with A/C, that may be another check of the dme control.

you may consider other components such as the water pump or thermostat. water pump bleed can be done in car with no special tools to test water pump function.

history codes will be stored even without check engine light and that could provide direction if you can get the car scanned.

Thanks for the reply. I think the thermostat is okay, the upper rad hose gets super hot and the radiator is hot to the touch. Water pump I think is okay because I did the bleed procedure and the pump sounds healthy. I'll see if the A/C kicks the fan on.

Looks like I need to invest in a scan tool...