Aux fan?

[LVP]

Hi guys,

I think my aux fan is dead. Won't come on with AC and temp creeps when stuck in traffic. Cruising brings temp down to middle, but not lower, so I'd guess t-stat and pump ok. When I look up replacement vids, they all show fans in front of the rad. Mine is between the rad and engine. Is that replacement pretty straightforward? Remove shrouds, pull up, drop in replacement, and go? The one out front required bumper work from what I saw. Hopefully the coolant can stay in the rad and the rad can stay in the car for this.

I'm going to plug in and see if I can test it or if any codes. I'm also finding fans for my model (2004 4.4) but they look to be front of rad mounted. Are there some with fans in front and some behind rad?

Thanks in advance.

[andrewwynn]

From the factory e53 aux fan it's forward of the radiator.

Bumper cover must be removed but if you are willing to cut a little of the air ducting you can pull it out the top vs out the bottom (no need to loft car, might get away without removing the under belly skirt).

Foxwell scanner will command fan on to confirm fault also pulling the plug from the AC pressure sensor will engage the fan.

They are stupid pricey for OE and you have noticed that it's not entirely mission critical as you have a clutch driven fan also.

[Clavurion]

Originally Posted by andrewwynn

From the factory e53 aux fan it's forward of the radiator.

Models with N62 engine don't have viscous fan and electric pusher fan. Instead they have electric fan behind radiator.

https://www.realoem.com/bmw/enUS/sho...diagId=17_0290

[Bdc101]

Definitely check the 50 amp fuse before you pull the fan out and replace it. I believe it's behind the glove box in facelift models.

[Clavurion]

Originally Posted by Bdc101

Definitely check the 50 amp fuse before you pull the fan out and replace it. I believe it's behind the glove box in facelift models.

Easier to check voltage directly on the fan connector (X1800).

[andrewwynn]

Originally Posted by Clavurion

Models with N62 engine don't have viscous fan and electric pusher fan. Instead they have electric fan behind radiator.

https://www.realoem.com/bmw/enUS/sho...diagId=17_0290

Important distinction. My n55 the same and it will overheat at idle off the fan is not installed for some reason ;-)


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[Bmwe5320023.0]

Sounds like an aux fan.
You can test the connector if it's getting power like clauvarion said.
But these fans go bad and motors seize up or resistors burn.
New ones are not that expensive.

[LVP]

It was a "279D Output stage, electric fan" fault. There were two ways to test/force the fan on from within the software, neither worked.

For giggles, I called the dealer - $1,200 and there aren't any available. Maybe in a month he said.

[andrewwynn]

As others mentioned confirm power before ordering the new one. It's a giant fuse not likely blown but best to test. Pull the connector and measure for battery voltage on the fat wires. If you have a high end DMM like I do you can measure the frequency and duty cycle on the small wire/s and confirm the signal is being sent to spin the fan when you send the run commend

[Clavurion]

Originally Posted by LVP

For giggles, I called the dealer - $1,200 and there aren't any available. Maybe in a month he said.

That sounds crazy money compared how much these cost from German dealer.

https://www.hubauer-shop.de/de/lueft...427521767.html