Electric Fan - Once on -- Doesn't turn off!

123Britt · 02-13-2009, 08:21 PM

Ok -- looks like I have encounterd my first problem - at 20k.
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Once the fan comes on after about 20 min drive -- fan turns on and fails to turn off.

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My guess that since the water temp sensor is not on & I have checked the water level & oil -- must be a temp themocouple switch failure. Either this or a much bigger over temp issue.

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I did a search & did not seem to produce any common thread as to a fleet wide failure with temp sensor or thermostat related failures.
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Thoughts??

Fritzables · 02-14-2009, 04:11 AM

I had the same thing happend to me recently. It turns out to be the Electronic Thermostat that fails. As a precaution the ECU puts the fan on flat out as it has no idea what the thermostat is doing.

I had my thermo replaced under warranty.

Fritzables.

lkn · 02-14-2009, 05:37 AM

I had the same problem; take it to the dealer to get the sensor replaced.

123Britt · 02-21-2009, 09:01 AM

Correct - the thermostst was replaced - they did have to order the part - 2-days.
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The dealer changed / flushed the brake fluid while they had the car - so ALLs Good in the NeighborHood.

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blue2fire · 02-25-2009, 01:05 AM

Was about to say thermostat when i looked at the last post, good to know they fixed it.

Mrbangis · 02-25-2009, 01:08 AM

i may have encountered this recently! im gonna check it out again!

02-13-2009, 08:21 PM	#1
123Britt Captain 318 Rep 873 Posts Drives: 15 M235i AT; 2008 Z4 3.0Si MT Join Date: May 2008 Location: Madison, Alabama iTrader: (0)	Electric Fan - Once on -- Doesn't turn off! Ok -- looks like I have encounterd my first problem - at 20k. . Once the fan comes on after about 20 min drive -- fan turns on and fails to turn off. . . My guess that since the water temp sensor is not on & I have checked the water level & oil -- must be a temp themocouple switch failure. Either this or a much bigger over temp issue. . . I did a search & did not seem to produce any common thread as to a fleet wide failure with temp sensor or thermostat related failures. . Thoughts??
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02-14-2009, 04:11 AM	#2
Fritzables Private First Class 10 Rep 132 Posts Drives: 2007 323i M-Sport Join Date: Jan 2008 Location: Brisbane AUSTRALIA iTrader: (0)	I had the same thing happend to me recently. It turns out to be the Electronic Thermostat that fails. As a precaution the ECU puts the fan on flat out as it has no idea what the thermostat is doing. I had my thermo replaced under warranty. Fritzables.
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02-14-2009, 05:37 AM	#3
lkn Lieutenant Colonel 23 Rep 1,549 Posts Drives: 335i Join Date: Oct 2007 Location: Orange County iTrader: (4)	I had the same problem; take it to the dealer to get the sensor replaced.
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02-21-2009, 09:01 AM	#4
123Britt Captain 318 Rep 873 Posts Drives: 15 M235i AT; 2008 Z4 3.0Si MT Join Date: May 2008 Location: Madison, Alabama iTrader: (0)	Thermostat Replaced Correct - the thermostst was replaced - they did have to order the part - 2-days. . The dealer changed / flushed the brake fluid while they had the car - so ALLs Good in the NeighborHood. . .
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02-25-2009, 01:08 AM	#6
Mrbangis Lieutenant Colonel 193 Rep 1,703 Posts Drives: 2018 M3 GrigioTelesto Join Date: Dec 2008 Location: Socal iTrader: (3)	i may have encountered this recently! im gonna check it out again!
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