First, I want to say I am happy for Efan users. You can tweak and have closed loop control over the engine temps, you have better access for working on the car, less parasitic loss, and no fan blades to smash into your hood.
If you are unfamiliar with how a clutch fan works here it is:
TL;DR: A fan clutch is a device that responds to the air temperature coming through the radiator. It uses a fluid coupling and a bi-metallic switch to engage or disengage the engine fan within a specific temperature range. It’s also designed to limit fan speed at higher RPMs. This part is considered unserviceable and is responsible for providing airflow when the vehicle is at rest or moving at lower speeds. When it fails, it can either stay disengaged (causing overheating) or remain fully engaged (causing excessive fan noise and drag).
Now, for those who would like to maintain an entirely OE-style cooling system, I’ve been collecting information. For most, there are no issues with using fully OE components. However, as parts quality continues to decline and the availability of the OE parts that many enthusiasts originally used to baseline their cars diminishes and as dealer pricing becomes less reasonable it’s becoming more challenging to keep the system as it was intended. I think it is important or getting more important to scrutinize and document what works and what doesn't work for parts. I think it is also important to document items going NLA to avoid good used parts getting thrown out or to help stockpile NOS parts.
Something like a clutch fan, I consider a fairly mission critical part that's important can pop up on a 90+ degree day where you are forced to idle and crawl through traffic, or when you come off track and are waiting on grid.
With that being said the known quantity here that has served people well for many years:
__________________________________________________ __________________________________
OE E46 M3 Fan Clutch:
BMW Part Number: 11527831619
OE (Behr) Part Number: 8MV 376 733-001
Mahle: CFC75000P (behr and mahle got bought or merged in 2010 https://workshop-heroes.mahle.com/en...-becomes-mahle)
If you source just a Behr/mahle replacement without the BMW Sticker this is probably what you will get
As Anri has shared here: https://nam3forum.com/forums/forum/m...182#post231182
This makes sense as it aligns with what the coolant gauge reads for that fan clutch engagement temperatures.
__________________________________________________ __________________________________________________ _________
With the stock Behr/Mahle setup established as the baseline, the next logical step is to look at how the community has experimented with other clutches. For those with lower temp thermostats or in very hot climates
Below is a summary of community findings:
Lets say you want alternatives for a more aggressive clutch fan here are the options:
All the options stem back to this BMW number. 11527505302 which was considered as a tropical fan clutch to European E36s but was the standard fan clutch for E36 M3s USA.
D
This first comes back to the HPF and AA upgraded fan clutch.
https://store.activeautowerke.com/products/e36-e46-sport-fan-clutch-323-325-328-330-m3
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr
Note the very different bi metallic spring design. The reviews are very poor on FCPEuro as people are complaining they are always on so maybe they are that aggressive or it is quality thing and they're bad out of the box. I have not ordered one myself to confirm, but the attached facebook user seemed very pleased.
I did have an incident where fan hit my crumbling shroud and exploded. My friend gave me free replacement clutch fan and it had an identical bi metallic spring design. It was from a E39 525i. It does have a very aggressive lock up, have used it in the Houston summer no issues. I have also done quite a few track events with it.
–––––––––––––––––––––––––––––––––––––––––––––––––– ––––––––––
SACHS 2100 010 031 (E36 M3 Fan Clutch – Confirmed by Anri)
Credit where it’s due — this section of information originates from Anri of Euro Classic Motors (SoCal), whose deep technical posts on NAM3Forum have helped clarify how the E36 M3 fan clutch interacts with lower-temperature thermostats.
It's recommended as a great pairing with his 70C Thermostat, if you are unfamiliar with that here is the thread:
At the time of this post, Sachs had already marked the 031 as to be discontinued, though stock remained in circulation through various resellers and NOS parts.
Based on both catalog data and owner reports, it’s a direct-fit part on S54 cars and provides noticeably stronger low-speed engagement without affecting high-RPM behavior.
–––––––––––––––––––––––––––––––––––––––––––––––––– ––––––––––
Tropical Sachs E36 M3 Fan Clutch 2100 010 032
While researching the 031 fan clutch, I discovered that Sachs also produced a tropical variant — the 2100 010 032. This was a new finding that hadn’t previously been discussed in the E46 community.
This “tropical” calibration is a Sachs tradition seen on several older models (E28, E32, Mercedes W123/W124, etc.), where the clutch is tuned to engage at a lower air temperature for markets in hotter climates. These are genuine Sachs parts, not aftermarket rebrands, and are identified in the catalog as “for tropical climate zones.” It's also lighter interestingly enough.
https://aftermarket.zf.com/en/catalo...amp;country=ES
According to Sachs this is for 11521737489 but it doesn't directly correlate with a vehicle on RealOEM.
However, it does say it is a 75 Celsius fan clutch on RealOEM so I ordered one from Rock Auto to test. I will report findings once I test it. The 032 is also planned to be discontinued so we are left only with older stock.
https://www.realoem.com/bmw/enUS/partxref?q=11521737489
If you are unfamiliar with how a clutch fan works here it is:
TL;DR: A fan clutch is a device that responds to the air temperature coming through the radiator. It uses a fluid coupling and a bi-metallic switch to engage or disengage the engine fan within a specific temperature range. It’s also designed to limit fan speed at higher RPMs. This part is considered unserviceable and is responsible for providing airflow when the vehicle is at rest or moving at lower speeds. When it fails, it can either stay disengaged (causing overheating) or remain fully engaged (causing excessive fan noise and drag).
Now, for those who would like to maintain an entirely OE-style cooling system, I’ve been collecting information. For most, there are no issues with using fully OE components. However, as parts quality continues to decline and the availability of the OE parts that many enthusiasts originally used to baseline their cars diminishes and as dealer pricing becomes less reasonable it’s becoming more challenging to keep the system as it was intended. I think it is important or getting more important to scrutinize and document what works and what doesn't work for parts. I think it is also important to document items going NLA to avoid good used parts getting thrown out or to help stockpile NOS parts.
Something like a clutch fan, I consider a fairly mission critical part that's important can pop up on a 90+ degree day where you are forced to idle and crawl through traffic, or when you come off track and are waiting on grid.
With that being said the known quantity here that has served people well for many years:
__________________________________________________ __________________________________
OE E46 M3 Fan Clutch:
BMW Part Number: 11527831619
OE (Behr) Part Number: 8MV 376 733-001
Mahle: CFC75000P (behr and mahle got bought or merged in 2010 https://workshop-heroes.mahle.com/en...-becomes-mahle)
If you source just a Behr/mahle replacement without the BMW Sticker this is probably what you will get
As Anri has shared here: https://nam3forum.com/forums/forum/m...182#post231182
"Behr fan clutch will engage at around ~93-98C and will shut around at ~85-88.."
This makes sense as it aligns with what the coolant gauge reads for that fan clutch engagement temperatures.
"Coolant temp gauge reads straight up and down from 85-95*C, it starts to move right at 96*C and when it's getting into the red zone its about 107*C (ish).
__________________________________________________ __________________________________________________ _________
With the stock Behr/Mahle setup established as the baseline, the next logical step is to look at how the community has experimented with other clutches. For those with lower temp thermostats or in very hot climates
Below is a summary of community findings:
Lets say you want alternatives for a more aggressive clutch fan here are the options:
All the options stem back to this BMW number. 11527505302 which was considered as a tropical fan clutch to European E36s but was the standard fan clutch for E36 M3s USA.
This first comes back to the HPF and AA upgraded fan clutch.
https://store.activeautowerke.com/products/e36-e46-sport-fan-clutch-323-325-328-330-m3
Untitled by Sam DaJam, on FlickrUntitled by Sam DaJam, on FlickrUntitled by Sam DaJam, on FlickrNote the very different bi metallic spring design. The reviews are very poor on FCPEuro as people are complaining they are always on so maybe they are that aggressive or it is quality thing and they're bad out of the box. I have not ordered one myself to confirm, but the attached facebook user seemed very pleased.
I did have an incident where fan hit my crumbling shroud and exploded. My friend gave me free replacement clutch fan and it had an identical bi metallic spring design. It was from a E39 525i. It does have a very aggressive lock up, have used it in the Houston summer no issues. I have also done quite a few track events with it.
–––––––––––––––––––––––––––––––––––––––––––––––––– ––––––––––
SACHS 2100 010 031 (E36 M3 Fan Clutch – Confirmed by Anri)
Credit where it’s due — this section of information originates from Anri of Euro Classic Motors (SoCal), whose deep technical posts on NAM3Forum have helped clarify how the E36 M3 fan clutch interacts with lower-temperature thermostats.
Originally posted by Anri
View Post
It's recommended as a great pairing with his 70C Thermostat, if you are unfamiliar with that here is the thread:
To take full advantages from the 70C Sachs Fan clutch is a Must !!!
At the time of this post, Sachs had already marked the 031 as to be discontinued, though stock remained in circulation through various resellers and NOS parts.
Based on both catalog data and owner reports, it’s a direct-fit part on S54 cars and provides noticeably stronger low-speed engagement without affecting high-RPM behavior.
–––––––––––––––––––––––––––––––––––––––––––––––––– ––––––––––
Tropical Sachs E36 M3 Fan Clutch 2100 010 032
While researching the 031 fan clutch, I discovered that Sachs also produced a tropical variant — the 2100 010 032. This was a new finding that hadn’t previously been discussed in the E46 community.
This “tropical” calibration is a Sachs tradition seen on several older models (E28, E32, Mercedes W123/W124, etc.), where the clutch is tuned to engage at a lower air temperature for markets in hotter climates. These are genuine Sachs parts, not aftermarket rebrands, and are identified in the catalog as “for tropical climate zones.” It's also lighter interestingly enough.
https://aftermarket.zf.com/en/catalo...amp;country=ES
According to Sachs this is for 11521737489 but it doesn't directly correlate with a vehicle on RealOEM.
However, it does say it is a 75 Celsius fan clutch on RealOEM so I ordered one from Rock Auto to test. I will report findings once I test it. The 032 is also planned to be discontinued so we are left only with older stock.
https://www.realoem.com/bmw/enUS/partxref?q=11521737489
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