brushless AUX fan (DME controlled) vs. brushed aftermarket fan (w/manual control)
 

I think that all the replacement fans for our X5's are brushless; the DME regulates fan operation via PWM signals that the brushless fans need. Brushed fans just need a potentiometer to change speeds.

Brushless fan motors are also thinner, which helps them fit in tighter spots like between the grille and radiator; I use an aftermarket brushed fan (replacing the stock viscous fan in my '01 X5), and it is thicker in cross-section than the AUX fan.

I use an aftermarket (Chinesium) motor speed controller to adjust fan speed on the high-cfm fan I installed. It can really make a lot of uneccessary noise (and draw more amps than needed) when idling at stoplights or when the airflow thru the radiator doesn't need that much fan speed, so I tune the speed down accordingly. The DME does the same for the (brushless) AUX fan, automatically.

I had to replace the one in my 2002 3.0 in 2022. I replaced it with a Mahle Behr unit which was not cheap then, but has gone up around $200 since. Currently $555.99 at FCP Euro. Ouch. If I were doing it again, I might have to consider something like the Topaz.

FWIW, when my auxiliary fan went, the AC stopped working altogether. I also pulled it from the bottom, which required removing the outer bumper panel. Definitely not a super fun job.

Chris
Lockhart TX
2002 X5 3.0 Titansilber
2005 X5 3.0 Schwarz 2

I had to cut some plastic duct i think to pull mine out the top. I was pretty happy to do it that way. I used aftermarket fan from Amazon cost $100. It wasn't any louder than the og fan.

Mine has a TOPAZ Condenser cooling fan 64546921381. Replaced by removing the bumper.

TYC vs TOPAZ fan: whatever works is fine
 

X5chemist- I thought you recommended the TYC fan, not the TOPAZ??

from my thread segment, concerning replacing the AUX fan (segment begins at post #76)
https://xoutpost.com/1240290-post93.html
Attachment 84821

Alright I've decided to order the TYC fan; should arrive next week. In the meantime though, I shouldn't have any problems driving right? I went to do some errands today and it's still hovering between 92-96c operating temp. Thankfully. The next two days will in the low 70s(F) then it'll be in the 50s for the rest of the week.

I checked my spreadsheet and Amazon history. It’s a TOPAZ. Fans look so much alike. Is the TYC brushless? It might be why I referred to it.

from TYC
 

I own and recommend a TYC fan in the E53..I replaced mine in 2021, and no problems.

TYC is made in Taiwan and comes with a lifetime warranty. Topaz is almost certainly made in China.

BimmerBreaker makes an interesting comment about failed PWM wires in the following thread.

https://xoutpost.com/bmw-sav-forums/...oogle_vignette

I wonder if TOPAZ is the same OEM manufacturer for Audi and VW? Probably not. We know who likes to infringe on copyrights.