Modernizing the E31

[TxGR8White]

Has anyone here converted their radiator fans to electric like the newer models?
If so, any tips??

Thanks

[cartoonz]

Not a fan... no, really. My advice is - Don't.

Best upgrade is the E65 fan & fan clutch combo. Need 4 M6x12 bolts to make it work

[LappingLuke]

Curious what improvement is realized with the E65 fan

[Hyper]

Oh man, I was like totally sucked in by the thread title.
Thought we were going to hear about 10 speed transmissions and back up cameras.

[TedBobo]

Curious what improvement is realized with the E65 fan

Ditto!

[Goodguyili]

Curious what improvement is realized with the E65 fan

The fan blades are better designed, and they are concentrated more within their sheathing. Sucks the out air better from the radiator. @bdiefAZ can attest for that since he has it done on his 8. I know when I finally get time to do the refresh on mine, I will do the same. I already have the fan and clutch. It's a cheap and easy mod to do.

Sent from my SM-G970U using Tapatalk

[m6bigdog]

I did the E65 radiator fan & clutch update on my M73 with a 105mm water pump pully. M73 uses a 93mm pully for US.
FWIW: 105mm pully is 13% slower water pump speed, however my 850 is upgraded with a 3.23:1 diff and that provide 15% increase in RPM/MPH.

E65 Radiator Fan & Clutch Upgrade:
https://www.bimmerforums.com/forum/s...1#post30182131

Benefits:
Much less fan roar on cold start. Unsure if that is the fan design or the clutch, just much less roar!!
Fan looks like the fan blade design used with an electric motor.
I anticipate it is a much more efficient fan design; 9 blade curved with blade shroud vs 11 blade straight fan design with fixed radiator shroud only, hence it moves more air per RPM and for power applied, due to less fan blade surface area (i.e. drag).
More Modern!!

[LappingLuke]

Interesting. My car sounds like a UPS truck at 2000 RPM a lot of the time. The fan sounds ridiculous but it moves freely by hand when the engine is off...

[rogbmw]

I know someone who had changed to the E65 not too long ago. It just exploded on them last week, which will require the hood to be refinished...

[henryc]

I own several E46 BMWs - Coupe, Convertible and Touring. In the E46 world, we proactively replace (also mentioned and recommended in Mike Miller's Old School Maintenance Schedule) the plastic fan, fan clutch, along with the plastic sided radiator, plastic overflow tank, plastic thermostat assembly and other cooling system bits at around 8 years or 90,000 miles. These items on the E46 fail due to age. Some parts will last longer, some shorter.

I follow the same proactive maintenance/replacement schedule on my E31. / Henry

[Braymond141]

I own several E46 BMWs - Coupe, Convertible and Touring. In the E46 world, we proactively replace (also mentioned and recommended in Mike Miller's Old School Maintenance Schedule) the plastic fan, fan clutch, along with the plastic sided radiator, plastic overflow tank, plastic thermostat assembly and other cooling system bits at around 8 years or 90,000 miles. These items on the E46 fail due to age. Some parts will last longer, some shorter.

I follow the same proactive maintenance/replacement schedule on my E31. / Henry

If you're going to list off replacing the mechanical fan, you at least need to recommend one of the primary causes as to why they fail; The motor mounts. It is not proactive to replace aged fan plastic as that is rarely the real cause. It's also important to use a fan clutch that actually works and isn't some cheapo model that drives the fan 1:1 with the engine the entire time.

[m6bigdog]

As for early or low milage fan failures, I anticipate they are most often caused from mishandeling the plastic fan (dropped, stepped on, stressed, etc.) before the fan was installed or reinstalled after maintenance.
The 11 blade fans are also prone to coming apart.
Attached image, of the cracked fan from my E38-740 with the same fan as the E31.
Continued use would have surely caused a fan failure.
Lucky? Maybe? however, an E38 is a BMW that requires a ton of maintenance, so there is a lot of opportunity to inspect parts.
Also, my EOS schedule is every 3k miles.

Records show this was the 2nd replacement fan (@168K miles) and the crack was discovered after 45k miles, during a routine EOS inspection.
I suggest carefully inspecting the fan before it is installed, during EOS inspections and any time the fan is removed during maintenance.
Also. if the fan clutch fails-locks-up and replaced, replace the fan as it has had a workout with a locked up clutch.
Also, the fan should be included in the engine plastic parts replacement (60-90k mile) maintenance schedule.ote]

[bdiefAZ]

E65 fan for the win!
More airflow, less noise.

We have tested them on 850's, 840's, M5's, and 540's here in Arizona. My 850 fan is under driven as well and increased airflow vs. stock fan setup.

[rogbmw]

out flows airflow.

Wow Brian...say that 10 times real quick..."out flows airflow, out flows airflow....."

Just a little Thursday morning humor! Hope all is well in AZ!

[bdiefAZ]

Good catch Roger, all is well here in AZ, we even have airflow that is being out flow-ed!

Wow Brian...say that 10 times real quick..."out flows airflow, out flows airflow....."

Just a little Thursday morning humor! Hope all is well in AZ!

[bdiefAZ]

I own several E46 BMWs - Coupe, Convertible and Touring. In the E46 world, we proactively replace (also mentioned and recommended in Mike Miller's Old School Maintenance Schedule) the plastic fan, fan clutch, along with the plastic sided radiator, plastic overflow tank, plastic thermostat assembly and other cooling system bits at around 8 years or 90,000 miles. These items on the E46 fail due to age. Some parts will last longer, some shorter.



I follow the same proactive maintenance/replacement schedule on my E31. / Henry

Henry, The e46 is easy to upgrade the engine fan to electric, its even plug and play!:

Part number 17117561757

1 remove clutch fan and shroud
2 install the manual transmission electric fan that has its own shroud and uses fasteners from old shroud
3 remove auxiliary fan in front of the condenser
4 plug new fan into the connector from the auxiliary fan

If you want to under drive the water pump: Install the S52 water pump pulley on the M52Tu / M54 engines with the 6PK1562 belt

The 11511730554 pulley from the S52 cars is 132mm in diameter
The 11511436590 pulley from the M54 cars is 122mm in diameter

This mod is also Arizona tested!

[Rickwalk]

Oh man, I was like totally sucked in by the thread title.
Thought we were going to hear about 10 speed transmissions and back up cameras.

My thoughts exactly ( as I look up into my 850 abyss) !! I thought Count Kustom's did the make-over...

[Fatandre]

I am about to mount the fan. Should I use loctite on the small screws?