FYI: Mechanical Fan to Electric Fan Swap

going to do the cooling system soon... so this is a good time to remove the clutch fan and toss it. sounds way too simple not to do. Ken, I have a normal "non noob" question (sure you can appreciate that lol) When you installed the fan as a puller behind the radiator... did you utilize the stock fan shroud? and did it have to be modified in anyway(the fan shroud)?

Stock fan shroud is gone. The electric fan is one whole unit.

Do these fans die at all? Are they dif between the 323,325,330?

sometimes the control module on the fan will fry. happened to my buddy. it stays on and constantly drains the battery. but its rare.

Originally Posted by kpeng

Stock fan shroud is gone. The electric fan is one whole unit.

cool. does that fan you suggest in post#1 include any mounting items? or did you simply zip tie it?

Great job Ken, I will be doing this mod once I do my cooling system overhaul with a stewart pump as well, I wonder what a dyno would show heck I would be happy would even 3 rwhp because every bit counts.

Originally Posted by BeMyWhip

cool. does that fan you suggest in post#1 include any mounting items? or did you simply zip tie it?

Mounts up to factory mounting points.

Am I misunderstanding what is being done here, or would this also make working on the car easier? It seems that on auto tranny cars, taking out the mechanical fan is a real pain but the electric one is pretty easy. I'd be inclined to do it for that purpose alone.

Yes sir, you are correct.

Question: do you swap the AUC module from the mechanical shroud to the electrical shroud ? And what is the AUC module for anyway ?

Cancel this....did another search. This switches the AC to recirculation mode as needed. I will simply move this over to the electric shroud. thanks

Does this apply to M52TUs as well? because I've been reading a lot about the swap and am almost ready to do it, but I'm just held back by this:
Everyone that I've read about had M54s, and everybody still think manuals ALWAYS come with an electric. THIS IS WRONG!
Early manual E46 models have, like mine, a mechanical puller + an electric pusher.
My questions are: when did BMW throw away the dual fan system on manual cars? Is the swap really safe for manual M52TUs? Will a M54 electric fan work?

Originally Posted by El Polo

Does this apply to M52TUs as well? because I've been reading a lot about the swap and am almost ready to do it, but I'm just held back by this:
Everyone that I've read about had M54s, and everybody still think manuals ALWAYS come with an electric. THIS IS WRONG!
Early manual E46 models have, like mine, a mechanical puller + an electric pusher.
My questions are: when did BMW throw away the dual fan system on manual cars? Is the swap really safe for manual M52TUs? Will a M54 electric fan work?

I've done it on my SC'ed M52TUB25

The pusher fan was removed to make room for the intercooler , and the mechanical blew to bits a couple thousand miles ago.

Had the car overheat during rush hour and finaly got an electric one , the one i got though was either improperly wired or was supposed to push air from the engine through the radiator(wtf?)

So i switched the fan's positive/negative and now it works like a charm , can leave the car idling for 20min or drive through 10mph traffic the needle won't move

Just want to clarify, so if I put the electric fan, there will be no bus sound coming from my car when the weather is really hot?



Also, in order to take off the AUX fan, I'm gonna need to remove the radiator?

That's an interesting question ... do you have to remove the pusher fan from in front of the radiator? Replacing the mechanical fan with an electric fan, should be moving the AUC module from mech. shroud to elec. shroud, and plugging the large multiwire plug into the plug that powers the fan. Can both electric fans remain in place and both be functional?

Ok, so I guess I'll try this out...
also, good question from sansho, how do you remove the aux fan?

Originally Posted by Sansho

That's an interesting question ... do you have to remove the pusher fan from in front of the radiator? Replacing the mechanical fan with an electric fan, should be moving the AUC module from mech. shroud to elec. shroud, and plugging the large multiwire plug into the plug that powers the fan. Can both electric fans remain in place and both be functional?

No, both cannot be there at the same time. You are correct otherwise.

I like the idea of one single fan - makes sense to me. Also, I am thinking of upgrading to a better aluminum radiator and running a separate trans cooler.
Then, I get the best of all worlds, while providing more protection to the auto trans. In Vegas, anything to keep the motor cool is a plus.

Originally Posted by huskerick

I like the idea of one single fan - makes sense to me. Also, I am thinking of upgrading to a better aluminum radiator and running a separate trans cooler.
Then, I get the best of all worlds, while providing more protection to the auto trans. In Vegas, anything to keep the motor cool is a plus.

Those things definitely would not hurt.

damn . people can't read.

lol

this is on my to do list.

So, I'm sure I'm over-thinking this, but found it interesting. Using the diagram below which shows the auto transmission cooling setup... Note that the coolant which is routed to the auto transmission heat exchanger includes the the heated coolant from the engine along with the coolant exiting the heater. That means the transmission fluid has to be hotter than the mixture coming from the engine in order to cool the transmission. So, with hot coolant cooling the transmission fluid, I wonder why BMW continued to use a fan/clutch on automatics?