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Mechanical fan delete!

19K views 46 replies 17 participants last post by  FLE39 
#1 ·
Mechanical fan delete in the making :thumbup:

I've thought about the Zionville alum shroud and expansion tank, but their price is cut throat if you ask me.

Here's my order with Summit Racing.

Not yet shipped 1 DER-16749 - Fan Control, Thermostatic, Adjustable, 150 to 240 Degrees, Kit $39.95
1 SUM-G4904 - Electric Fan, Single, 16 in. Diameter, Reversible, 2,010 cfm, Black, Plastic, Each $84.95

Stay tuned!
 
#4 ·
So this replaces the fan blade & fan clutch on the M54? The cost for that is about equal to or less than a new fan blade & fan clutch. Please post up a DIY, if you don't mind, as I would contemplate this changeover. I need to replace my cooling system this spring.
 
#16 ·
I usually hang out in the E38 section but I'm planning on going with an electric fan on my M62 motor, and I'm going to buy something like what Schitzo posted. I'd just like to make a suggestion.

A little while back, I did an electric fan on a car that came with a fan and clutch, with an electric fan kit (relay, wires, temp sensor), and I had to put a brass T-fitting to get the factory temp sensor for the ECU and the temp sensor for the fan on the same threaded hole in the intake manifold in the car. When I did this, it just happened that the T-fitting was facing up, and since there was air in the fitting where the temp sensors were, with no way to bleed the air that was touching the sensor, the engine was getting to "hot" before the fan was cutting on.

So my suggestion is, either get a temp sensor that's threaded to fit in the housing that touches the coolant and take out that brass fitting in Schitzo's picture, or mount the housing upside down so that the coolant will hit the sensor instead of air. You guys see what I mean?

BTW, there is no need to buy one of the one or two hundred dollar electric fans you see for sale in some places. You can get an electric S-blade fan that came factory on the newer style Lincoln Towncars from a junkyard for somewhere around $15, which should be more than sufficient to cool down these motors. It just won't come with a shroud. That and a $50-$60 electric fan kit, and however much that hose splicer/connector costs, and you are good to go.

I look forward to seeing how you guys set this up in your cars. :)
 
#17 ·
I
So my suggestion is, either get a temp sensor that's threaded to fit in the housing that touches the coolant and take out that brass fitting in Schitzo's picture, or mount the housing upside down so that the coolant will hit the sensor instead of air. You guys see what I mean?

I look forward to seeing how you guys set this up in your cars. :)
Good point but as long as the sensor is not mounted on the top most section of the cooling system and you thoroughly bleed your system, you should not have air pockets to worry about.
 
#22 ·
I'd say avoid tapping into an already existent minor circuit to avoid overloading it and creating electrical issues.
I tapped into the battery junction that is just below the drivers footwell. This junction connects the battery to the starter and alternator. You would then connect the power wire from the junction to a fuse then to a relay and finally to your fans. You will have clean power that does not interfere with the already stock circuits. Also use relatively heavy gauge wire.You can make a completely plug and play harness that is nice clean and safe. ...and since im a pic whore here is mine.
http://img28.imageshack.us/img28/9963/img09290.jpg
 
#25 ·
We don't need to introduce any more electrical gremlins to our car do we? Thank you Schitzo, you're da man :thumbup:. I will definitely look into this route for sure.

I have a question for you though. As you know I'm getting a variable temperature relay control, and as I was reading the instruction, besides the main power supply, which we are talking from above, there's another power signal that the instruction wants to hook it up to the ignition. I don't know the purpose of this power signal at all. Is it just a switch to enable the relay circuit? TIA.
 
#23 ·
this is from the DIY I used when I did the zionsville colling kit.
Part Two - Electric Fan Wiring Installation

So, for the wiring, I chose to install the relays in the relay box under the passenger carbon intake air filter. After removing the air intake filter box, an allen head bit is required to remove the four securing bolts for the relay box cover.



I placed both relays in the relay box in the same locations noted by Blacksapphire. I tapped into a 8 GA constant 12V source for the electric fan relay power. (Top right corner in the photo, thicker red wires attached to a terminal on the side of the relay box) I may rerun this constant 12v connection to the battery post by way of the engine wiring flex tunnel at the top right of the relay box. I'm suspect of tapping into this 12V in the relay box as I don't know what it feeds. Anyone know?



I used a Dremel to notch the side of the relay box to run the remaining wires from both relays in a high temp wiring sheath to the engine compartment. The wires I ran were the red power feeds for the electric fan power, the orange switched 12V sense wires, and the two gray wires that run to the Zionsville temperature switch for the two speed function.



I ran the wiring sheath to the interior engine compartment through an access gap I found under the existing wiring conduit. There was a foam plug I removed that was just the right size for the 3/8" wiring sheath.



Next, I ran the two orange wires inside the factory sheath to the diagnostic socket. I tested for a switched 12V source. I read this was a green wire with a white stripe. I soldered both orange wires to the green wire with the white stripe. Once this was done, I rewrapped the wiring harness to retain a factory look.



Next I installed the resistor for the low speed fan power. This resistor gets hot, so I took a lead from BlackSapphire and used a pair of copper/aluminum tubing cut to 1/4" to standoff the resistor from the body. I used a Dremel with a cutting wheel to cut the tube to length. I fastened the resistor and standoffs with two 1" black machine screws.



Resistor shown in the lower center in the picture below. I still have some clean up tie wraps to install.



I attached the two required grounds at the ground connection shown in the lower right of the pic above to the right of the low speed fan power resistor. I next installed the coolant temp switch and attached the gray wires to the appropriate leads. Low speed to T1, High speed to T2. All wires still in the high temp wiring sheath.

(Picture below just showing the Zionsville fan temp switch next to the Coolant Expansion Tank before I wired the gray wires and also before I connected the fan power feed and ground.)
 
#24 · (Edited)
There were pictures to go along with that.
 
#30 ·
On my 2004 E39 525i Touring (Euro spec) the electrical pusher fan (condenser fan for the air conditioning) is started automatically when the return temperature from the coolant radiator reaches about 80-85 Celsius (185F). The fan speed is infinitely variable (or if it is 15 steps, dont remember).

The viscous clutch for the mechanical fan is designed to engage at a higher temperature and only when the electrical fan doesn't have enough power.

The mechanical fan has never engaged for me, not even in the summer with over 30C (85F).

I have also seen (by monitoring radiator outlet temperature with a PC) that the factory fan speed regulation for the electrical fan is very effective when it comes to use just the right amount of power, that is: not waste energy and not let the engine temperature rise.
 
#33 ·
Thanks for the update!

I like it! Did you find the rubber isolators you were looking for? That SUM-G4904 you used looks like it fits perfectly into the shroud with just the right amount of gap for the bolts.

With temperatures in the the 20s here, I'm not sure you really need it for some time. :thumbup:
 
#37 ·
You've probably already explained this but it hasn't stuck to my brain cells very well....

How do you plan to install the temp sensor?

Also, considering that these cars already have lots of electrical gadgetry running, will this fan put any strains on the alternator?

When I have extra $, I plan to do several things in this area (including filling with npg+) but for now I'm just in popcorn mode....
 
#39 ·
Your plan is to cut the rad hose and install a splicer like the one Schitzo showed?

I'm taking notes.... would like to see comments from others that have done this with their 528 and whether they've had any problems afterward.

The idea appeals to me because I see it giving the water pump a longer lifespan.
 
#47 ·
Guys, about 7 yrs ago I was doing a lot of electric fan conversions on older Toyota Supras and trucks/4runners. I had extremely good luck going tot he U-pull parts place and getting a 2 speed SHO Taurus type fan with Bosh motor. and the controler came from Summit racing. It has a probe you insert into the radiator fins and you can adjust the kick on temp. Fully auto, professional setup. Worked great in the most extreme cases off-roading. Nice thing is you don't mod the car's cooling system or wiring and can convert back to stock.
 
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