Radiator Fan Doesn't Kick In

Statesdatruth · 03-10-2022, 12:54 PM

Hey guys,

Last week my coolant hose burst and I had a battery light come up. I towed my car to my mechanic and he took a look at it and figured that the radiator fan did not kick in and the pressure from the system caused the coolant hose to burst.

The issue is that its been at the shop for over a week and he can't figure out what's going on. He's assuming its a problem with the car's ECU. He tested out the radiator fan (which works), checked the fuses, the relays, the sensors, and tested the wiring. He claims that the ECU is probably not sending out a signal to the radiator fan to kick in when it reaches a certain operating temperature, and wants to get it reprogrammed.

Miroslaw Boldys · 08-21-2022, 06:18 AM

The reason may be a failure of the water cooler thermostat.

Eyeman · 08-26-2022, 05:58 PM

My car was running hot in traffic a couple of years ago (but it would go into very hardcore limp mode so nothing was damaged). I think the fan not kicking on was the issue that my mechanic fixed. He didn't seem confused.

03-10-2022, 12:54 PM	#1
Statesdatruth Registered 2 Rep 1 Posts Drives: 2009 BMW 128i Join Date: Mar 2022 Location: Toronto iTrader: (0)	Radiator Fan Doesn't Kick In Hey guys, Last week my coolant hose burst and I had a battery light come up. I towed my car to my mechanic and he took a look at it and figured that the radiator fan did not kick in and the pressure from the system caused the coolant hose to burst. The issue is that its been at the shop for over a week and he can't figure out what's going on. He's assuming its a problem with the car's ECU. He tested out the radiator fan (which works), checked the fuses, the relays, the sensors, and tested the wiring. He claims that the ECU is probably not sending out a signal to the radiator fan to kick in when it reaches a certain operating temperature, and wants to get it reprogrammed.
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08-21-2022, 06:18 AM	#2
Miroslaw Boldys New Member 0 Rep 6 Posts Drives: BMW F11 520d Join Date: Aug 2022 Location: Polska iTrader: (0)	The reason may be a failure of the water cooler thermostat.
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08-26-2022, 05:58 PM	#3
Eyeman Colonel 121 Rep 2,037 Posts Drives: 2008 135 blk, blk, step Join Date: Jan 2009 Location: Atlanta, GA iTrader: (0) Garage List 1994 Porsche 968 Cab [0.00] 2017 AMG GTS [0.00] 1994 Porsche 968 Coupe [0.00] 1977 Mercedes 450SE ... [0.00] 2008 135 [8.00]	My car was running hot in traffic a couple of years ago (but it would go into very hardcore limp mode so nothing was damaged). I think the fan not kicking on was the issue that my mechanic fixed. He didn't seem confused. __________________ Injen, RR OCC, MadDad Whisper, donut spare, 19x8.5et43fr 19x9.5et45r Volk LE37's, rear fenders rolled/pulled, PSS4S 225/35fr 255/30r, KW V1's, AR coated catless dps, Cross strutbar, CF grills and license plate holder, iCarbon diffuser, ETS black anodized FMIC, M3 control arms, Quaife, ER chargepipe, ForgeDV's, Topspeed Custom Tune, V3sims, Braille, Andrey_GTA rear hub mod, Ebay Mstyle front bumper and performance style side skirts.
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