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Z4M electric fan retrofit?

25K views 50 replies 20 participants last post by  tangerine-dream 
#1 ·
I've been contemplating deleting the mechanical fan, but I don't really want to go with an aftermarket solution. I've been tempted to retrofit the non-M electric fan, but always held back because I'm not sure if it would be powerful enough (I think it'll fit though. Radiator brackets seem to be the same).

Now looking at the z4m - it has a 600W electrical fan (compared to the 390w fan in the non-Ms). Mounting points are identical to the e46 non-M fan. I'm thinking this should do the trick since it's from an s54 car. And it should into the existing connector. One potential issue is that the z4m comes with a different radiator (same radiator as e46 non-M actually). Another issue is that it's expensive ($500 shipped at thebmwpartstore.com)

Before I attempt this - has anyone attempted either this fan or the non-M electrical fan? Can they at least mount up? If not, how difficult would it be to retrofit whatever piece has the screw holes? (would I need a new radiator or can I just swap some plastic bits?)
 
#3 · (Edited)
Looking at the diagrams, I think it should fit with little to no problem.

E46 M3 Shroud Diagram:

Code:
No. Description Supplement Qty  From   Up To  Part Number Price Notes Photo 
01 Radiator 43/9,4/66 1   17102228941 $385.75   
02 Fan shroud  1   17112228943 $74.77   
03 Air duct, left  1   17112228945 $31.72   
04 Air duct, right  1   17112228946 $31.72   
05 EXPANDING RIVET  3   17111712963 $0.27   
06 SUPPORTING PART  1   17117530252 $13.42   
07 SUPPORTING PART  1   17117530254 $13.42   
08 GASKET LEFT  1   17111436247 $10.10   
09 GASKET RIGHT  1   17111436249 $10.10   
10 BRACKET F.RADIATOR  2   17117514402 $5.83   
11 BRACKET F.RADIATOR  2   17111436264 $5.37   
12 RUBBER BUFFER  2   17111178412 $1.68   
13 Screw self-tapping D6X20 ZNS3 4   17117536971 $1.12   
14 Screw self-tapping  1  07/2004 17111716600  ENDED  
14 Screw self-tapping D6X40 ZNS3 1   17117536972 $1.12   
15 Bracket, fan housing  1   17112282209 $5.82
Z4M Cooling Fan (integrated shroud):



Code:
01 Fan housing with fan 600W 1   17427542912 $621.50   
02 Fan shroud  1   17427542913 $103.40   
03 Screw self-tapping 5X1,23X10 5   17427514831 $1.12   
04 Screw self-tapping D6X40 ZNS3 3   17117536972 $1.12   
05 Mounting plate  1   17117836843 $54.97   
06 Screw self-tapping D6X20 ZNS3 3   17117536971 $1.12   
07 EXPANDING RIVET  2   17111712963 $0.27
The Z4M fan mount is basically the same design as the E46 non-M fan. The left side seems like it matches up reasonably well (at least the top screw should). However, part number 5 seems to function as some sort of adapter which makes the right side mounting points match up with the M3 points.

Now I gotta see if I can find who makes the Z4M fan since I'd rather not pay $500 through BMW. Or I suppose I can just risk the non-M fan...
 
#4 · (Edited)
I would look into mounting depth. As there is not a lot of room between the radiator and the snout on the water pump where the old fan mounted onto. This is the most common issue. I've been looking at doing this too and if I can find a fan replacement that would guarantee to cool BETTER then the factory fan, then I would cut off the threaded snout of my new water pump giving me an extra 1.5" clearance and making it permanently electric only.

I don't see why this won't work though. The biggest issue with people is that they don't realize how much an improvement having a full shroud makes. I have been contemplating using a Zirgo 3365cfm fan and modifying the factory shroud to seal around the Zirgo fan.
 
#8 · (Edited)
Yeah that's one concern I had. I think it should work simply because e46 non-Ms convert from mechanical to electric all the time without issue, and they have the same mounting mechanism. If you think about it, there's enough room to back the mechanical fan out all the way without it getting stuck, and the electric fan wouldn't have that 32mm nut sticking off it.

One of these days I should borrow one of my non-M friends' fans and see how the fitment is
 
#6 ·
You generally can not return special order parts, especially electrical components.
 
#9 ·
I think it might be close.




You can use the fan control box on the right of the shroud(left side on ours) as reference to size. It might just clear.
 
#11 ·
After looking at pics. Looks like #5 is used on all of them from the factory on Z4M's
Well only reason I mentioned #5 is because that's one piece the Z4M has that the E46 non-M doesn't have, and it seems like the cirlced bits below correspond to one another. If that is indeed the case, it seems like there are at least 2 mounting points that will line up with our cars. The bottom holes might line up too



 
#13 ·
I know =/. I'm thinking about ordering that piece number 5, borrowing my friend's electric fan (he has a 330i), and see if it's at least possible to mount everything. Since the dimensions without piece #5 are the same between the Z4M and 330i fans (or at least they appear to be), that should give an idea if everything can be installed with a factory-like fit and finish.
 
#15 ·
That's correct, but extending wires and making a mount is not a big deal. You'd have to do wiring anyways to run the fan so.
 
#17 ·
We still haven't found a cheaper place to source this beast from? I've got to put my parts order in next week for my auto 330i and I might stick with a 390w fan.

Our temperatures get up to 100 farenheit but don't go below 50 or so here in Brisbane. I haven't found anyone who can tell me for sure whether the 390W fan is strong enough for an autoboxed car in a high temp environment or not, but I guess It's about my turn to be a Guinea Pig.

But still... If anyone can get a Z4M fan for less than $400 I'll be sold on it.
 
#18 · (Edited)
I don't really know where to look. Pelican only has the "Genuine BMW" listed, and most other sites don't even list the part. Z4M isn't exactly a common car, so I guess the demand for non-BMW branded OEM parts isn't very high (and I doubt the fan fails very often). Cheapest I've found is thebmwpartstore.com at $500 shipped. I haven't really tried asking any local dealers, but I doubt they'd be much cheaper. I'm tempted to just try the 390W version. I can't imagine running into any issues with the temperatures we get around here
 
#20 · (Edited)
I might add that according to Realoem.com, all the Z4's had 490W fans and the "hot-climate" versions (hopefully the Australian cars!) had 600W fans like the Z4M.

Basically, the 600W fan wasn't just on the Z4M and a plain E85 fan is still an upgrade on an E46 fan.


EDIT: I just paid $7.50 for a 600W Z4 fan off ebay. *WIN*
 
#23 ·
trive2: Have you got any further with this? Interestingly enough, it seems the Z4 does not have an AC condenser fan like us. So this one 600w fan is both the engine and ac fan. It would surely be enough cooling for us then coupled with our electric fan up front. Although, in theory, we could eliminate it completely and just run the Z4 fan.
 
#31 · (Edited)
Any new updates on this project? I noticed the Z4M came with a 150amp alternator. Thats 30 more amps than the E46 M3.
 
#34 ·
Don't think so.... I still really want to try this, but do not have a hole burning in my pocket. Lol. Especially since there is nothing wrong with my system now...
 
#35 ·
I may have dropped the ball on this... A buddy of mine, who lives just around the corner, has a Z4M. I meant to investigate the physical swap, but I only got to the point of taking some rough measurements. At first glance, I'd say the chances of it fitting are not good.

I'm traveling for pretty much the next month, so I won't have a chance to monkey with it in the next 5 weeks. If I can get some photos, I'll get them up here.
 
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