Here's what a bad Aux fan looks like

[J.Belknap]

All the magic smoke got out and went to electronics heaven



PWM motor integrated to fan.



New fan happily in place. New AC condenser dryer fitted. AC system properly evacuated then charged.



When the aux fan fails AC refrigerant temp goes up, pressure goes up, the compressor will purge excess high-side pressure, after a cooldown there wont be enough refrigerant volume in the system to allow the compressor to activate again.

[bcredliner]

Might want to check out this thread. The Spal replacement for the clutch fan arrived this AM. http://www.xoutpost.com/bmw-sav-foru...-electric.html

I decided to add a thermostat control to the setup based on research and your thread.

[upallnight]

Originally Posted by bcredliner

Might want to check out this thread. The Spal replacement for the clutch fan arrived this AM. http://www.xoutpost.com/bmw-sav-foru...-electric.html

I decided to add a thermostat control to the setup based on research and your thread.

But what do you do for the signal from the DME to control the fan speed and turn it on when the ac is on?

[J.Belknap]

Originally Posted by bcredliner

Might want to check out this thread. The Spal replacement for the clutch fan arrived this AM. http://www.xoutpost.com/bmw-sav-foru...-electric.html

I decided to add a thermostat control to the setup based on research and your thread.

Thanks for the link bc, I will be retaining the OEM mechanical fan.

[sv1cec]

J.Belknap, I have the same issue with my aux fan, it doesn't work. Since I very rarely use the air condition and since my car never shows any signs of overheating, I tend to leave it as is, but I always think about replacing it. So here are a few questions, if you do not mind:

1. Did you had to remove the whole front bumber to remove the fan? If not, do you have a description of how to remove the fan without removing the bumber? Tried the search but didn't get anything back.

2. Did you use a new OEM fan? What was the cost?

Thanks for your time.

[J.Belknap]

John,

1) You will remove the front bumper cover or at least slide it off far enough to remove the fan left trim, fan right trim, fan bottom trim, fan grille, and slide the rest of the assembly down behind the crashbar and out of the truck. Here are the TIS procedures for YOUR 2005 3.0d.

BMW TIS

a) Go to repair manual, E53, 51 trim, Front Bumper, Removing and installing / replacing the lining of the front bumper (since 10/2003)
b) Go to repair manual, E53, 17 Cooling, Additional electrofan, Removing and installing / replacing auxiliary fan assembly (M62, M54, M57)

2. I purchased an OEM fan from Tischer BMW (getbmwparts.com) YOUR 2005 3.0d part number is 64546921382

getbmwparts.com sells this part for $464.06 but you may find it cheaper to purchase in Europe.

[sv1cec]

Typically, European BMW prices are more or less the same as yours, only in Euros, which means they are about 35% more expensive than what you Americans pay. Of course, that depends on the country. For Greece, it's what I just wrote, for Bulgaria it's something like 40% less. Crazy continent we are living in.

Thanks for the excellent guide, I really appreciate it. I've bookmarked those links, very interesting.

Somehow, I think that if I ever decide to fix this problem, I'll have the local dealer do it, which means an over 1,000€ job!

[cn90]

Old thread but considering that the Aux Fan for M54 cars (E39, E53 etc.) is expensive ($400-$600), does anyone know the EXACT cause of the Aux Fan failure?

1. Is it seized bearing causing overheat of the electronics?
2. Or the electronics goes bad with age?

If the cause is #1 above, then routine maintenance such as every 8 years/80K miles or so, one should disassemble the fan motor and lubricate the bearings inside to prevent seizing?

Just a thought...

[Ricky Bobby]

Based on the pictures I'd say its #2 - especially since the fan is PWM operated

[bcredliner]

I don't recall anyone mentioning they have done PM on Aux fan though I don't look at all threads. To me it is one of those parts like a water pump. Sooner or later it will wear out, just hope it is a long time.

I seldom lubricate electrical parts because of the risk to get the lub somewhere that will destroy the part.

Some replace the mechanical fan before there is a problem as there have been fans that have thrown blades and caused other damage and the performance of the mechanical fan can decline but go unnoticed. As you can see by this thread I don't think much of mechanical fans.

I am still running the original aux. fan. When it dies it dies. Not feeding it any vitamins.