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X5 E70 (2007 - 2013)
E70 BMW X5 produced between 2007 and 2013. Discuss the E70 X5 with other BMW owners here.

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  #1  
Old 07-23-2016, 08:25 AM
Edmond Sokol Edmond Sokol is offline
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Location: Charleston, SC
 
Join Date: Jul 2016
Posts: 15
Mein Auto: 2011 X5
Really loud auxiliary fan

Hello fellow BMW X5 owners:
I have a 2011 X5 in which the auxiliary fan comes on only when I have the A/C on.

It starts even after car has been sitting overnight and I start car and it comes on and it is LOUD. Not a noise from it being defective but just so powerful.
Took to dealership and they say it's normal but I have talked to many BMW owners in parking lots or in traffic and NONE of them say their's sounds like mine does.
When I lift the hood the air coming out is like a HURRICANE!
I can even hear it with windows up.
Why would aux fan come on as soon as I start car and only when A/C is on. If I turn OFF A/C the fan goes off as soon as I do.
ANY HELP MUCH APPRECIATED! THANKS!
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  #2  
Old 07-23-2016, 09:06 AM
Doug Huffman's Avatar
Doug Huffman Doug Huffman is offline
Nuclear engineer
Location: Washington Island, Wisconsin, thru Death's Door
 
Join Date: Apr 2015
Posts: 2,455
Mein Auto: 2012 X5 35d (E70)
E70 Climate Controls Systems, page 38. Only mention

The A/C compressor is always loaded while A/C is on, and is ONLY throttled for idle power control, to prevent evaporator icing, and for high power control. Temperature is regulated by hot water to the left and right sides of the heating heat exchanger.

It's hot summer in Charleston. How noisy the fan is I can't tell, but too noisy is often caused by damaged blades.

Quote:
Pressure Sensor via Junction Box
The refrigerant pressure input signal is a direct junction box input signal and is relayed to the IHKA via the K-CAN. The IHKA requests actuation of the auxiliary blower by the DME (ECM) depending on the refrigerant pressure [switch visible in the aluminum pipe passenger side rear of the engine compartment].

The IHKA determines the relevant A/C compressor load torque on the basis of the input signals from the pressure sensor and the compressor speed. The DME (ECM) control units are notified of the load torques by the IHKA and used by the DME (ECM) as input variables for actuating the electric fan.
Consult with an automotive HVAC shop. Sorry, I've been away too long to make a recommendation.
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Last edited by Doug Huffman; 07-23-2016 at 09:11 AM.
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  #3  
Old 07-23-2016, 09:12 AM
edycol edycol is offline
Officially Welcomed to the 'Fest
Location: Colorado Springs
 
Join Date: Jul 2015
Posts: 1,240
Mein Auto: 13' BMW X5 35d
Quote:
Originally Posted by Edmond Sokol View Post
Hello fellow BMW X5 owners:
I have a 2011 X5 in which the auxiliary fan comes on only when I have the A/C on.

It starts even after car has been sitting overnight and I start car and it comes on and it is LOUD. Not a noise from it being defective but just so powerful.
Took to dealership and they say it's normal but I have talked to many BMW owners in parking lots or in traffic and NONE of them say their's sounds like mine does.
When I lift the hood the air coming out is like a HURRICANE!
I can even hear it with windows up.
Why would aux fan come on as soon as I start car and only when A/C is on. If I turn OFF A/C the fan goes off as soon as I do.
ANY HELP MUCH APPRECIATED! THANKS!
Again, if this is OK then it is hot SC summer!
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  #4  
Old 07-23-2016, 11:18 AM
DefSport DefSport is offline
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Location: TX
 
Join Date: Sep 2015
Posts: 514
Mein Auto: E70 35i, S13
The fan is cooling the AC condenser. That's normal.
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