DIY: Aux/mechanical fan to electric fan swap

All you need is is this:

floor jack and one jack stand
philips screwdriver
I think Torx 20 head
8" extension
ratchet
8mm socket or 8mm wrench
9mm socket
13mm socket
fan clutch tools
OEM electric fan: 17117561757
Expanding rivets: 51718229003 (4)
51118174185 (as many as your break)
51471919209 (as many as your break)


- Jack up one side of car (I did the drivers side) and put one jack on the metal plate
- Remove the 8mm bolts holding bumper to the fender liners
- Take out the reinforcement bolts with 9mm socket/ratchet/extension
- Slide bumper out (unclip wiring for fogs and horn)
- Take out the top air intake
- The center duct is held by four pop in screws
- Aux fan is held by four 13mm nuts, take them out
- Disconnect the aux fan by the fan shroud in the engine bay
- Slide the fan out
- Put the center duct back in and top air intake
- Put the front bumper back on in reverse order (slide in, put in the two reinforcement bar bolts and the assorted bolts to the liners.
- Next you have to take the mechanical fan out
- Pop out the fan control unit on the shroud and the other wiring and put them to the side
- Take out the 1 torx screw on the passenger side top and loosen up the fan shroud
- Use the fan clutch tool to loosen the bolt and take out the assembly
- Take your electric fan and slide it against the radiator and screw in the torx screw
- Plug the electric fan to the connector where the aux fan was plugged into
- Place back the control unit and the other wiring to the electric fan shroud

Viola, you're done.


I will make a DIY video later.

Let me add some pictures.
Got BEHR fan for $199 shipped from here: http://cgi.ebay.com/ebaymotors/ws/eB...=STRK:MEWNX:IT


Work in progress:



Yuck!


I am so glad I had to mess with mech fan removal for LAST time!



Now, need to cleanup the crap off the condenser and begin to assemble back.

Ok, job's done!




I tested it by idling and monitoring coolant temp (func 7.0). Fan engages at 90C at slow speed (no A/C) and if I turn on A/C and temp rises up to 92C the fan starts to work faster and temp quickly goes down back to 90C. But even at high speed its noise is a whisper in comparison with aux/mech fans' noise. Later will do a test drive.

Thanks for the pics. I am still waiting for my friend if he wants to do it.

A little bit more detailed DIY for bumper removal (btw, I never used 9mm during the process (coupe))
http://www.e46fanatics.com/howto/how...hp?howto_id=41

Originally Posted by Solidjake

All you need is is this:

floor jack and one jack stand
philips screwdriver
I think Torx 20 head
8" extension
ratchet
8mm socket or 8mm wrench
9mm socket
13mm socket
fan clutch tools
OEM electric fan: 17117561757


- Jack up one side of car (I did the drivers side) and put one jack on the metal plate
- Remove the 8mm bolts holding bumper to the fender liners
- Take out the reinforcement bolts with 9mm socket/ratchet/extension
- Slide bumper out (unclip wiring for fogs and horn)
- Take out the top air intake
- The center duct is held by four pop in screws
- Aux fan is held by four 13mm nuts, take them out
- Disconnect the aux fan by the fan shroud in the engine bay
- Slide the fan out
- Put the center duct back in and top air intake
- Put the front bumper back on in reverse order (slide in, put in the two reinforcement bar bolts and the assorted bolts to the liners.
- Next you have to take the mechanical fan out
- Pop out the fan control unit on the shroud and the other wiring and put them to the side
- Take out the 1 torx screw on the passenger side top and loosen up the fan shroud
- Use the fan clutch tool to loosen the bolt and take out the assembly
- Take your electric fan and slide it against the radiator and screw in the torx screw
- Plug the electric fan to the connector where the aux fan was plugged into
- Place back the control unit and the other wiring to the electric fan shroud

Viola, you're done.


I will make a DIY video later.

VIDEO VIDEO VIDEO VIDEO VIDEO VIDEO VIDEO VIDEO VIDEO VIDEO

So let me get this straight, you don't need the front pusher fan once you do this mod??

Correct.

Sorry if I over read anything but can't you just leave the pusher fan on the car? What's the point of taking it off too?

You can leave it disconnected, since the new fan will use the same connector the aux fan is using now. And as a downside of this decision - much worse air flow, since the shroud of the aux fan is pretty big. Plus, take a look on my pics above, how much crap is collected under the aux fan.

Originally Posted by alibusoul

Sorry if I over read anything but can't you just leave the pusher fan on the car? What's the point of taking it off too?

You can only have the electric fan alone. I would take it out because it will prevent airflow to go on the ac condenser.

Ok I see, so that electric fan alone will keep the engine from over heating? Because 2 years ago I took out the mechanical fan and I've only been running the pusher fan, but damn that thing gets really REALLY loud.

I wouldn't run only the aux fan.....

Just do the swap.

Interested in this swap, can you provide some more detail behind your motivation for it?

- No truck sound when the car is hot
- No chance of the mechanical fan blowing up and taking out MANY parts
- Car feels more responsive due to less drag on the engine
- Better airflow to ac condenser
- Electric fan held by one screw, no special tool needed like the mechanical fan

Add one more - better gas mileage. Before the swap my average weekly mpg was 23 - 23.5. Now it is 25 - 25.5. Nothing else was changed in the car.

You're welcome

See the original thread for more info:
http://forum.e46fanatics.com/showthread.php?t=744994

Many thanks to Solidjake for writing up a DIY though!

This is sweet, I was planning on doing this to my auto but wasn't to sure about keeping or removing the outer fan, but now i know. Another thing i wasnt to sure of was wether to stick with an OEM fan or not, since OEM is alot easier ill just stick with it. Thanks for the good info

Sent from my Dell Streak using Bimmer App

Originally Posted by kpeng

You're welcome

Today I reached 27 MPG - I never seen this number on my dashboard! Wow.

Originally Posted by kpeng

See the original thread for more info:
http://forum.e46fanatics.com/showthread.php?t=744994

Many thanks to Solidjake for writing up a DIY though!

You are welcome for pics!