[rontan]

Hi guys,
My car E90 N46B20 320i Auto 2008 non LCI has face the engine overheating during stationary or in slow traffic on last Monday. Air cond is not cold during these situations. the yellow overheating sign pop up in the meter cluster. I believe almost all of u will be saying air cond has nth to do with engine overheating, the engine overheating mostly will cause by waterpump.
Mechanic come to my place and check and said the coolant is there no leaking and he release the coolant clogged and ask me to drive for few days see if it is ok.
on the next day the same issue came back when in slow traffic. i send it to the workshop and they flushed the refrigerant and did the coolant adaptation. they said everything is ok no more fault code. they told me the fault code of radiator fan pop up b4 that, during diagnosed but now is no more, should be good. they even test drive my car for more than 20km without issue. on the next day i drove it to outstation for 150km journey without any issue.
this morning the problem happen again when i start my car, after parked for 2 days. this time is more serious in which i saw the red overheating sign pop up in the meter cluster! i open the engine hood and found that the radiator fan is not spinning(pls refer to video)! when i stop the engine i saw the coolant leak out from the expansion tank(u can watch the video i uploaded here)!
Solution:
after waiting my engine cool for awhile then i open the expansion tank, i refill it with water. then i spin the radiator fan manually just to make sure the fan didn't stuck. after that i go start the engine and come back to the engine bay, the fan is spinning. no more overheating, air cond is cool. drive back to my shop for 150km without issue.
Conclusion:
if u feel that your air cond is not cold when stationary, then it could be the radiator fan is not spinning. it will cause the engine to overheat soon until the car is moving(not at low speed). spin the fan manually then start the engine is a temporally solution but replacement for a new radiator fan must get it done as soon as possible.
Thank you for reading.

fan not spining
coolant leaking from the expansion tank

[rontan]

Fan not spinning (click the picture above for video)

[rontan]

Coolant leaking from expansion tank (click the picture above for video)

[crashoverride]

I'm confused. The fan is electric and not tied to say a dedicated engine pulley. Why would manually spinning a random electric fan cause that fan to work..??

I mean isn't there a sensor that turns the fan on? Wouldn't that be more likely the culprit..??

Or if the expansion tank needed fluid wouldn't that and not the fan be the main problem..??

[rontan]

Originally Posted by crashoverride

I'm confused. The fan is electric and not tied to say a dedicated engine pulley. Why would manually spinning a random electric fan cause that fan to work..??

I mean isn't there a sensor that turns the fan on? Wouldn't that be more likely the culprit..??

Or if the expansion tank needed fluid wouldn't that and not the fan be the main problem..??

hi,
it happen to my electrical old standing fan too. if u leave it for like few hours and ON it, the fan is not spinning. i have to manually spin the fan then it only works.
so it is happen to my old car now lol.
once the fan is not spinning, the coolant temperature will hike if the car is stationary while the engine is running, or during slow traffic. so once u stop the engine, you will see the water leaked from the expansion tank due to the water pump is stop.

[rontan]

just did a cold start. fan is not working. i have manually spin it and still not working. then realized the fan won't work if cold start or engine is not hot. lol! the air cond is blowing the hot air even though the engine is idling for 5 mins.
after driving some distance and the air cond is still blowing the hot air. park the car and open the engine hood. the fan is not working. stop the engine and manually spin the fan. start the engine then saw the fan is working. but it stop after around 5 mins and not working anymore. drive it around for 5 mins then park the car, check the fan and it is still not working. air cond is still blowing hot air. stop the engine.
leave it for 10 mins and start the engine, the fan is working. air cond is blowing cold air this time till i am going back to my shop and the fan is still working before i stop the engine.

[crashoverride]

Originally Posted by rontan

just did a cold start. fan is not working. i have manually spin it and still not working. then realized the fan won't work if cold start or engine is not hot. lol! the air cond is blowing the hot air even though the engine is idling for 5 mins.
after driving some distance and the air cond is still blowing the hot air. park the car and open the engine hood. the fan is not working. stop the engine and manually spin the fan. start the engine then saw the fan is working. but it stop after around 5 mins and not working anymore. drive it around for 5 mins then park the car, check the fan and it is still not working. air cond is still blowing hot air. stop the engine.
leave it for 10 mins and start the engine, the fan is working. air cond is blowing cold air this time till i am going back to my shop and the fan is still working before i stop the engine.

Yea manually spinning the fan is just happen chance and not fixing any of your problems. The e90 has a thermostatically controlled electric fan that will come on at random. Your fan isn't getting stuck its just not running when you are looking or "think" it should be running.

It sounds like a typical AC system that is low on fluid. It will blow hot and cold as pockets of the remaining refrigerant randomly make it through the AC system. Furthermore the radiator fan doesn't have anything to do with the AC temp. Sounds like you need to get your AC checked and serviced.

[rontan]

Originally Posted by crashoverride

Yea manually spinning the fan is just happen chance and not fixing any of your problems. The e90 has a thermostatically controlled electric fan that will come on at random. Your fan isn't getting stuck its just not running when you are looking or "think" it should be running.

It sounds like a typical AC system that is low on fluid. It will blow hot and cold as pockets of the remaining refrigerant randomly make it through the AC system. Furthermore the radiator fan doesn't have anything to do with the AC temp. Sounds like you need to get your AC checked and serviced.

my ac has done service and flushing. refrigerant pressure is good.
today the radiator fan is not working at all no matter what i try to do. weird is this time the ac is blowing cold air from the cold start lol. the idling rpm is up and down. red overheating sign pop up
car is in workshop now. fan replacement is in progress. i will see if the ac is good after the radiator fan is replaced. hopefully the engine head is still good.
Thank you.

[rontan]

Originally Posted by crashoverride

Yea manually spinning the fan is just happen chance and not fixing any of your problems. The e90 has a thermostatically controlled electric fan that will come on at random. Your fan isn't getting stuck its just not running when you are looking or "think" it should be running.

It sounds like a typical AC system that is low on fluid. It will blow hot and cold as pockets of the remaining refrigerant randomly make it through the AC system. Furthermore the radiator fan doesn't have anything to do with the AC temp. Sounds like you need to get your AC checked and serviced.

i am really hope that the radiator fan is the culprit. if not, then i will have to paid for the radiator fan. workshop telling me it could be the electronic system that cause the issue and might not because of the radiator fan. i am not sure if this has anything to do with the ecu?

[rontan]

Originally Posted by crashoverride

Yea manually spinning the fan is just happen chance and not fixing any of your problems. The e90 has a thermostatically controlled electric fan that will come on at random. Your fan isn't getting stuck its just not running when you are looking or "think" it should be running.

It sounds like a typical AC system that is low on fluid. It will blow hot and cold as pockets of the remaining refrigerant randomly make it through the AC system. Furthermore the radiator fan doesn't have anything to do with the AC temp. Sounds like you need to get your AC checked and serviced.

Click the image for video

[rontan]

new fan replacement done.
fan is working like normal now.
after car is started, air cond is blowing cold air.
idling is stable.