[Peter_Griffin_Gaming]

Hello to whoever's reading this. As the title states, I own a pre-LCI N52 E90 with the 6MT and no towing package, meaning that the car came with the 400W radiator fan. Now, being an idiot, I got into an accident which ruined my fan. (Fortunately, nobody else's car or property was involved in my display of dumbassery.) Continuing to be a dumbass, I went to a pick-and-pull and bought a 600W fan, unaware of the variance between non-M E90 cooling systems. Luckily, I can return it, but I was wondering if I could just upgrade to the 600W fan and reap whatever benefit comes from this. (Additionally, every E90 at that pick-and-pull was an auto, so I'm gonna have to go the online route if I need a 400W fan). I'm willing to do some slight modification if needed.
Thanks for any and all help.

[e90yyc]

Didn’t realize AT and MT e-fans were different! I suppose that makes sense, with the extra cooling loop for the trans fluid.

Having manual-swapped my car without changing the e-fan out, I can say I haven’t noticed anything out of the ordinary.

I’d hold onto the one you have

[hassmaschine]

I don't think it will hurt, but there's not really any benefit to the bigger fan. I'm assuming it's there for the transmission cooler. If it fit's and works I'd just go with it.

[M-technik-3]

Vheck the ratings on the fuse, might be a different relay involved as well.

[Peter_Griffin_Gaming]

Originally Posted by e90yyc

Didn’t realize AT and MT e-fans were different! I suppose that makes sense, with the extra cooling loop for the trans fluid.

Having manual-swapped my car without changing the e-fan out, I can say I haven’t noticed anything out of the ordinary.

I’d hold onto the one you have

Interesting! Gives me hope for this swap.
However, I'm wondering if you switched out the wire harness to the fan? It seems as there may be a wiring incompatibility between the 600W fan and my harness.

[Peter_Griffin_Gaming]

Originally Posted by hassmaschine

I don't think it will hurt, but there's not really any benefit to the bigger fan. I'm assuming it's there for the transmission cooler. If it fit's and works I'd just go with it.

Yeah, I doubt I'll see any big improvement going from the 400W to 600W fan. Mainly want to do this because the 600W fan is just what I have lying around.

Originally Posted by M-technik-3

Vheck the ratings on the fuse, might be a different relay involved as well.

This and wiring differences are what concern me. I found some diagrams of the wiring on this forum, but the links seem to be broken, which makes things harder.

[F31B48]

Originally Posted by Peter_Griffin_Gaming

Yeah, I doubt I'll see any big improvement going from the 400W to 600W fan. Mainly want to do this because the 600W fan is just what I have lying around.


This and wiring differences are what concern me. I found some diagrams of the wiring on this forum, but the links seem to be broken, which makes things harder.

The wiring is the same for both fans so you're all good there. See below diagrams from ISTA.

[Peter_Griffin_Gaming]

Originally Posted by EvaBmw

The wiring is the same for both fans so you're all good there. See below diagrams from ISTA.

Thank you so much, this is just what I was looking for! Glad to see that the fans are compatible, I was dreading having to either scour pick n' pulls for a 400W fan or pay out the nose online.

Edit: Looking throught the image again, I see that there's seemingly a difference with the pins. Do you think this is significant? I've marked up the 600W diagram with the 400W values in red.

[hassmaschine]

I think they are the same, but the pins are numbered different. Just compare the plugs - it's only 3 wires, red/blue for power, brown for ground, and black for the PWM signal from the DME. Worst thing happens, you can either splice the plug or swap the pins if needed. the fan control module itself is built into the fan, and they all work basically the same (power, ground, PWM signal).

[Peter_Griffin_Gaming]

Originally Posted by hassmaschine

I think they are the same, but the pins are numbered different. Just compare the plugs - it's only 3 wires, red/blue for power, brown for ground, and black for the PWM signal from the DME. Worst thing happens, you can either splice the plug or swap the pins if needed. the fan control module itself is built into the fan, and they all work basically the same (power, ground, PWM signal).

Got it, thanks. Hopefully the wiring is being plug-and-play, I'll check all of this when I can--don't have access to the car at this very moment. If worse comes to worst, I'll mess around with the wiring as you suggested.

[Clammy]

Originally Posted by Peter_Griffin_Gaming

Got it, thanks. Hopefully the wiring is being plug-and-play, I'll check all of this when I can--don't have access to the car at this very moment. If worse comes to worst, I'll mess around with the wiring as you suggested.

Glad I came across this thread, as I am in the same boat as you are. My 400W fan is making a HELL of a racket, so i went and grabbed a fan from a wrecker, without realizing the automatic cars came with the 600W version.

Have you installed the 600W fan in your car yet? Was it plug and play (fingers crossed)?

Thanks.

Cheers!

[Clammy]

Originally Posted by Clammy

Glad I came across this thread, as I am in the same boat as you are. My 400W fan is making a HELL of a racket, so i went and grabbed a fan from a wrecker, without realizing the automatic cars came with the 600W version.

Have you installed the 600W fan in your car yet? Was it plug and play (fingers crossed)?

Thanks.

Cheers!

Whelp, I answered my own question: not plug and play. The connectors are completely different... ugh... My stock fan is about toast, and all I could find in the yard were automatic cars with the 600W fan. Not sure what to do now. Either grab a connector off one of the other cars, and do some wiring, or buy a new fan, for stupid money...

[desertman123]

I'd just splice the 600w connector on, both ends. Solder + heat shrink, or if solder worries you (vibrations, cracking, blah blah big debate) then just use waterproof crimps.

Finding manual specific stuff is always fun!

[Peter_Griffin_Gaming]

Originally Posted by desertman123

I'd just splice the 600w connector on, both ends. Solder + heat shrink, or if solder worries you (vibrations, cracking, blah blah big debate) then just use waterproof crimps.

Finding manual specific stuff is always fun!

I ended up being able to use my 400W fan by taping the connector together and replacing a blown fuse. The fan itself was operational, it's just the connecter clips that broke.
However, it's making a bit of noise on shutdown now. If it ends up breaking, I'm just going to fit a 600W fan as you described. I have no desire to try and find the 400W unit at a good price.