Another Electric Fan Thread

[bmdubya1198]

I'm in the process of a cooling system refresh, and I've been planning on installing an electric fan. I set up a used E39 shroud I had with a Volvo 2 speed electric fan (I'm a Volvo guy too, I have tons and tons of Volvo parts lying around) and I was going to run it off a Hayden radiator probe-style fan controller. I went to test fit the fan today (finally) and the motor is too big to clear the water pump pulley.
Now I could make some more revisions to my setup, or just order a slimmer Spal fan or something, but I don't really want to have a bunch of messy wiring that may or may not always work (I've got no problem cleaning it up, but you get the idea). My aux fan works fine, so I'm not worried about potential failure of the controller or anything, but after all the work I've put into this setup I'm considering just saying screw it and ordering a new fan clutch.

So my question to those who have installed e-fans in 6 cylinder E39s... is it worth it? Does it really improve throttle response that much? I recently converted the fan on my brother's E34, and while it helped it rev a LITTLE quicker, these 6 cylinders just rev pretty lazily in stock form. Especially with the automatic. The throttle response difference was nothing to get excited about.

Does anybody have any real world numbers/feedback on swapping from the mechanical fan to the electric fan? This car is a daily driver, not a track car, so I don't think it's a huge deal, but I just can't leave well enough alone lol. If I can improve something, I'd like to do it!

[seagreen323i]

I was dinking around with my e46 one time and pulled the clutch fan to see what all the fuss was about. Made a pretty good difference in throttle response. This was a manual though (yes I know manual e46s where suppost to have electric fans but this was a first month production so idk) this was the 2.5 liter m52tu with cable throttle. Electric throttle might hinder any gains as well as it being an autobox if applicable. The biggest gain i would see from this is the ability to turn on/ramp up your fan however you like. Better idling cooling for dd duties. So 30 ish pound flywheel vs torque converter its a wash.

In terms of revving quicker it freerevved quicker for rev matching. None of that matters with an auto. Better while accelerating, nope. Loaded up that fan turns off anyways most of the time. Might make the water pump last longer due to less shockloading. Don't quote me on that though.

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[bmdubya1198]

Thanks for the input! I might pull it just to see how it feels, but I think I'll wait on it now. At least until I manual swap the car (planning on doing that once I find a parts car). Maybe the increased drag from the fan is why BMW went with an electric fan in the manual E46?

I have heard about it potentially improving water pump life, but I'd have to read more about that.

[computiNATEor]

Thanks for the input! I might pull it just to see how it feels, but I think I'll wait on it now. At least until I manual swap the car (planning on doing that once I find a parts car). Maybe the increased drag from the fan is why BMW went with an electric fan in the manual E46?

I have heard about it potentially improving water pump life, but I'd have to read more about that.

I still don't know why they made the double cooling fan decision on the E39. Doesn't make sense to me, but it works. After you replace both fans every 150k. :rolleyes

[seagreen323i]

Thanks for the input! I might pull it just to see how it feels, but I think I'll wait on it now. At least until I manual swap the car (planning on doing that once I find a parts car). Maybe the increased drag from the fan is why BMW went with an electric fan in the manual E46?

I have heard about it potentially improving water pump life, but I'd have to read more about that.If its cool outside you can remove the fan for a little while. Just don't idle for hours and it'll keep temp.

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[bmdubya1198]

I still don't know why they made the double cooling fan decision on the E39. Doesn't make sense to me, but it works. After you replace both fans every 150k. :rolleyes
Yeah, I don't know why they did that... same for the E53. Meanwhile all E83s had electric fans.

If its cool outside you can remove the fan for a little while. Just don't idle for hours and it'll keep temp.

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I might go ahead and do that.

[seagreen323i]

I would reccomend to stay moving, keep the air flowing. I knew a girl who had a broken fan blade and ran without it for at least a week.

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[balidawg]

A side note for the later E39 models with DME-controlled variable speed electric fan...

It doesn’t need the mechanical fan and clutch. I have been running without it for years, same on my E46s.

I’d like to see someone retrofit an E46 puller electric fan onto E39, and of course remove the pusher fan. It would literally plug right into the existing connector and work perfectly. I’ve been meaning to do this project, document it, and share, for a while now, but too many other projects in front of that. The fan diameters are both around 16” and an E46 e-fan is less than $100.

[computiNATEor]

A side note for the later E39 models with DME-controlled variable speed electric fan...

It doesn’t need the mechanical fan and clutch. I have been running without it for years, same on my E46s.

I’d like to see someone retrofit an E46 puller electric fan onto E39, and of course remove the pusher fan. It would literally plug right into the existing connector and work perfectly. I’ve been meaning to do this project, document it, and share, for a while now, but too many other projects in front of that. The fan diameters are both around 16” and an E46 e-fan is less than $100.

+1, but not sure that will provide enough cooling for an M5.

[bmdubya1198]

A side note for the later E39 models with DME-controlled variable speed electric fan...

It doesn’t need the mechanical fan and clutch. I have been running without it for years, same on my E46s.

I’d like to see someone retrofit an E46 puller electric fan onto E39, and of course remove the pusher fan. It would literally plug right into the existing connector and work perfectly. I’ve been meaning to do this project, document it, and share, for a while now, but too many other projects in front of that. The fan diameters are both around 16” and an E46 e-fan is less than $100.

Huh, now that's interesting. It would certainly be worth a shot if it's controlled exactly the same. The changeover on that was '99 IIRC, so mine has the DME controlled fan. Plus, being DME/PWM controlled, I'm sure it's not too hard to make adjustments to the activation temperature.

For my brother's E34, I ran the Volvo 2 speed fan off the stock switch and wiring. The fuses Volvo used for those were rated at the same amperage as the BMW fuses, so it should be able to handle it. Plus the Volvo puller fan offers more flow than the pusher fan that was seized up in this car, so it's a win-win. No custom wiring required, all I did was cut and splice the BMW connector to the Volvo fan so it's all removable. I may go ahead and change the switch out for the lower temperature E36 switch.
Mounting it was super easy too... Volvo 940 fan shroud, just trimmed a little off the driver side. I'm going to add a foam strip to close the gap. I added a pretty ugly but functional tab on the bottom to center it on the radiator.
685384685385

[BMW540san]

I've had this setup on my 532M for years now and I've had it for years on 540 and X5 before I sold both. I'm about to install it on my X5 3.0 and between 3 of these cars I've probably had well over 12 years / 100k miles of troble free operation:
https://forums.bimmerforums.com/forum/showthread.php?2073823-Electric-fan-conversion-completed-on-97-BMW-528i

The specific Spal model fan I use on all of my setups is very quiet, pushes a lot of CFM and there is a lot of room to work on front of the engine. The wiring is simple and all components are high quality.

I'm particulary proud of my "patented" setup where everything looks OEM. I don't like the "naked" look of some electric fan setups where shroud is removed, not to mention that shroud is there to help the direction od air flow.

https://i.postimg.cc/J02QTSR0/IMG-20210212-082406402.jpg (https://postimg.cc/rR5Wsn02)

https://i.postimg.cc/FswZ0tPn/IMG-20210212-082432945.jpg (https://postimg.cc/9rtZjkHG)

[jclausen]

Or you can just leave it stock and replace the parts that are worn out, simple

[bmdubya1198]

I like that setup! Very cleanly done. I would definitely keep the stock fan shroud, or some sort of shroud, since just zip tying a fan onto the radiator like many people do isn't going to be nearly as efficient as a setup with a shroud.


Or you can just leave it stock and replace the parts that are worn out, simple

But what's the fun in that? We have to mess with things... that's the whole point of me starting this thread! Lol

[balidawg]

+1, but not sure that will provide enough cooling for an M5.
Agreed, that would only be good for the I6 flavor.

[computiNATEor]

The E60 had some powerful electric fans throughout its lifetime. Wonder if one of those could be made to fit.

[JimLev]

Agreed, that would only be good for the I6 flavor.

My Flex-a-Lite trim line fan installed in my 540 shroud works fine.