Auxillary Fan Operation

[shimmy]

Can anybody who really knows, try to explain to me how, when, and why he Auxillary electric fan operates in he S54 lump in our cars.

I'm keen to know what criteria turns it on and off.

(I'm nt talking about the mechanics clutch fan on the engine side of the rad but the electric fan you see from the front grill)

[mattCSLnut]

Isn't that the A/C electric cooling assist fan for when one's stuck in slow moving traffic with the A/C On :)
It usually comes on when the natural air flow to the A/C rad (which is in front of the main engine cooling rad ) is reduced, most noticeably is slow city driving on a hot day) as the temperature of the A/C gasses increases requiring additional cooling.
IIRC none A/C Cecils don't have this AUX electric fan.

[shimmy]

Isn't that the A/C electric cooling assist fan for when one's stuck in slow moving traffic with the A/C On :)
It usually comes on when the natural air flow to the A/C rad (which is in front of the main engine cooling rad ) is reduced, most noticeably is slow city driving on a hot day) as the temperature of the A/C gasses increases requiring additional cooling.
IIRC none A/C Cecils don't have this AUX electric fan.

That's the one, just need to know exactly how it works and why it is needed

[alexk]

shimmy, I could be wrong but I think the electric fan is also installed on the non-AC cars.

The fan is used to provide additional cooling to the engine. It's not used just for the AC.

Here are the maps that show how the fan is operated.

Temperature (°C)|Operation/speed (%)
|49°C|0%
|50°C|30%
|70°C|40%
|80°C|65%
|85°C|83%
|90°C|100%

The second map, that changes the voltage supply depending on the speed.
Above 140km/h it's deactivated.

speed (km/h)|Voltage (index)
|0 km/h|1
|50 km/h|1
|100 km/h|1
|120 km/h|0.5
|140 km/h|0
|200 km/h|0

[shimmy]

Alex.........brill.


So above 140kph or 87.5mph the Aux fan stops nd ultimately blocks air into the front of the car.


Any idea why they would do this?

How could you have a switch to override it to let it run above 140kph?

[O'Neill]

Alex.........brill.


So above 140kph or 87.5mph the Aux fan stops nd ultimately blocks air into the front of the car.


Any idea why they would do this?

How could you have a switch to override it to let it run above 140kph?

At that speed the air turning the fan would turn fan faster than the motor.

[O'Neill]

Might not though due to pressure.

[shimmy]

At that speed the air turning the fan would turn fan faster than the motor.


I need to put a camera on it and see if it is held stationary by the motor when not powered.


.

[alexk]

How could you have a switch to override it to let it run above 140kph?

This is the map in the ECU.
Changing the map would change the behavior.
But I think O'Neil is right about the speed of air.

[shimmy]

shimmy, I could be wrong but I think the electric fan is also installed on the non-AC cars.

The fan is used to provide additional cooling to the engine. It's not used just for the AC.

Here are the maps that show how the fan is operated.

Temperature (°C)|Operation/speed (%)
|49°C|0%
|50°C|30%
|70°C|40%
|80°C|65%
|85°C|83%
|90°C|100%

The second map, that changes the voltage supply depending on the speed.
Above 140km/h it's deactivated.

speed (km/h)|Voltage (index)
|0 km/h|1
|50 km/h|1
|100 km/h|1
|120 km/h|0.5
|140 km/h|0
|200 km/h|0

What about viscous fan guys?

[shane@mbtech]

No electric fan. Viscous only Alex.

shimmy, I could be wrong but I think the electric fan is also installed on the non-AC cars.

The fan is used to provide additional cooling to the engine. It's not used just for the AC.

Here are the maps that show how the fan is operated.

Temperature (°C)|Operation/speed (%)
|49°C|0%
|50°C|30%
|70°C|40%
|80°C|65%
|85°C|83%
|90°C|100%

The second map, that changes the voltage supply depending on the speed.
Above 140km/h it's deactivated.

speed (km/h)|Voltage (index)
|0 km/h|1
|50 km/h|1
|100 km/h|1
|120 km/h|0.5
|140 km/h|0
|200 km/h|0

[shimmy]

No electric fan. Viscous only Alex.

I find that strange Lawsy as surely when the cr stops and the fan is running, non a/c cars must have the same cooling (it's not a/c that's running

[shane@mbtech]

Viscous fan is temp controlled. The viscous coupling has in laymans terms a fluid that when hot causes the 2 sides of the coupling to turn together.

Imagine the coupling spinning with engine speed as it's attached the pulley. When cold no drive is transmitted through to the fan side of the coupling. When hot the fluid changes and locks the fan.

Approx 30mph then the opposing air does more than the fan could pull through.

[shane@mbtech]

I find that strange Lawsy as surely when the cr stops and the fan is running, non a/c cars must have the same cooling (it's not a/c that's running

The non AC cars have the viscous fan to cool them.

[shimmy]

The non AC cars have the viscous fan to cool them.

Just engine driven?

Not electric?

[shane@mbtech]

Just engine driven?

Not electric?

Yes shim, just engine driven on m3.

Have a little read http://en.m.wikipedia.org/wiki/Fan_clutch. It gives you the basics.

My viscous fan was new on my Csl as it started overheating one day whilst queuing in a petrol station.

[Mike R]

Yes shim, just engine driven on m3.

Have a little read http://en.m.wikipedia.org/wiki/Fan_clutch. It gives you the basics.

My viscous fan was new on my Csl as it started overheating one day whilst queuing in a petrol station.

Is the CSL viscous fan ECU controlled or bi-metallic metal strip?

[CraigMillwardCroft]

Now I am getting confused mine has two fans, one viscous back of rad on engine and one in front of the rad electric which is standard, came on today while car was standing with engine running for long time.

[Mike R]

Now I am getting confused mine has two fans, one viscous back of rad on engine and one in front of the rad electric which is standard, came on today while car was standing with engine running for long time.

I suspect that the electric fan is to provide the low speed / traffic cooling that the viscous one cannot meet the demands for, so perhaps there is a cross-over point where the two are not operating as efficiently as the cooling demands?

[shimmy]

Now I am getting confused mine has two fans, one viscous back of rad on engine and one in front of the rad electric which is standard, came on today while car was standing with engine running for long time.

I presume you have a/c.

[CraigMillwardCroft]

I presume you have a/c.

Yes is that why the front kenlowe type fan then.

[alexk]

Is the CSL viscous fan ECU controlled or bi-metallic metal strip?

Bi metallic with quicksilver inside.

[shimmy]

Interestingly just read a thread on m3fourm.net where they point out that the front fan is higher on M3/CSL due to the bigger OeM oil cooler below meaning the fan works higher than the rad, also meaning the shroud cover more of the rad from front air flow at speed.

I think my plan before summer is to try:

Coolant flush and fill with better BMW coolant, antifreeze, wetter mixture (suggestions pls on %)

New AC condenser

Number plate base removing (for hot conditions.)

[Neil M]

Shimmy one of your problems might just be, that your in a hard water area in the South East. High levels of lime in the domestic water supply.
Essex experiences big problems as does parts of the Midlands with their domestic appliances furring up; boilers, washing machines, kettles, irons and the like. :whistle:

The same could be said for car radiators. You might need to add some sort of inhibitor, (like that used in your central heating system) I don't know if anti-freeze would do this job on its own. You might need to purge the system, or at least the radiator with a 'Calgon' type of treatment to clean it out and then use a distilled water/antifreeze mix in the car. :)

It's not something we suffer from North of Stoke, as 'lawsy' has previously commented.:thumbs:

[shimmy]

I'm not sure Simpsons put water in the radiator (I never touch the dam thing), surely hey use rad coolant

[shimmy]

Regarding fan position, look at post #17

http://www.m3forum.net/m3forum/showthread.php?t=459432&page=2

[alexk]

shimmy and all, do we have a photo of a non-AC CSL to see how the radiator looks like ?

What is interesting is that the heat-generating monster M5 F10 has no front radiator fan for the AC and only a rear electric radiator.
http://mfans2.com/parts/catalog/F10/Europe/M5-S63N/L-N/apr2012/browse/radiator/fan_housing_mounting_parts/#2283923_1

Here another information of the upgraded fan of the Z4 35is and 1M.
http://www.e90post.com/forums/showthread.php?t=797466

I think I will remove completely the fan clutch and the AC fan from my car.
I start to think that the AC fan and case is reducing the air flow.
Otherwise I cannot explain why BMW ditched it from the M5 F10 which is the most challenging car they ever built in terms of heat management.

[shimmy]

lots of US cars run without clutch fan and no issues, all very interesting

[alexk]

lots of US cars run without clutch fan and no issues, all very interesting

I will bin both of them :-D
Following the BMW way !

Alternatively, we could retrofit the 2 M5 water radiators (for the engine cooling).
It has another 2 for the charge-coolers and ECUs cooling, 1 engine oil radiator, 1 steering fluid radiator, 1 gearbox fluid radiator and 1 AC radiator.
8 radiators :beer:

[digi]

I'm not sure if you guys are talking about this, but when I had an E36 M3 I did do an AUX fan delete. Brought the kit from the US with something IIRC called water wetter. Its hot here and I had no issues with temp on the E36 M3.

[alexk]

shimmy and all, do we have a photo of a non-AC CSL to see how the radiator looks like ?

What is interesting is that the heat-generating monster M5 F10 has no front radiator fan for the AC and only a rear electric radiator.
http://mfans2.com/parts/catalog/F10/Europe/M5-S63N/L-N/apr2012/browse/radiator/fan_housing_mounting_parts/#2283923_1

Here another information of the upgraded fan of the Z4 35is and 1M.
http://www.e90post.com/forums/showthread.php?t=797466

I think I will remove completely the fan clutch and the AC fan from my car.
I start to think that the AC fan and case is reducing the air flow.
Otherwise I cannot explain why BMW ditched it from the M5 F10 which is the most challenging car they ever built in terms of heat management.

I found a CSL without AC and in front of the radiator there is nothing blocking the air (like in my M5).
I will get back later with some pics of my DIY.

[alexk]

I found a CSL without AC and in front of the radiator there is nothing blocking the air (like in my M5).
I will get back later with some pics of my DIY.

So here what I did to bin the AC fan -> http://www.cslregister.com/forum/showthread.php?p=165392#post165392

[terraphantm]

shimmy and all, do we have a photo of a non-AC CSL to see how the radiator looks like ?

What is interesting is that the heat-generating monster M5 F10 has no front radiator fan for the AC and only a rear electric radiator.
http://mfans2.com/parts/catalog/F10/Europe/M5-S63N/L-N/apr2012/browse/radiator/fan_housing_mounting_parts/#2283923_1

Here another information of the upgraded fan of the Z4 35is and 1M.
http://www.e90post.com/forums/showthread.php?t=797466

I think I will remove completely the fan clutch and the AC fan from my car.
I start to think that the AC fan and case is reducing the air flow.
Otherwise I cannot explain why BMW ditched it from the M5 F10 which is the most challenging car they ever built in terms of heat management.

BMW ditched the front fan in almost all of their vehicles. They have since opted to simply use more powerful fans. That electric fan in that M5 is a 1000W unit -- the AC fan in the M3/CSL is paltry 200W in comparison. The Z4M (S54) also ditches the AC fan in favor of a 600W puller fan in front of the radiator. Also note that the E46 non-M also has an electric-only fan, though only 400W

Rather than delete both fans, I think it would be best to put an electric fan in the front. I think the non-M fan would be sufficient for any M3 that isn't driven in the desert.

[uncle benz]

Nerdy fact of the day... If your viscous fan coupling is weak or failed completely, the car will use the a/c fan to reduce temperature if needed.

[shimmy]

Nerdy fact of the day... If your viscous fan coupling is weak or failed completely, the car will use the a/c fan to reduce temperature if needed.

Looking at the controls data AlexK posted on the electric fan, we can all see that Gareth......you'll have to work harder here to get a nerd prize :bigcry:

[Neil M]

I'm no expert at things mechanical but looking a the pics posted, it might make more sense to remove the radiator shroud than the fan, in terms of increasing air flow.
The surface area of the fan appears minimal compared to that of the shroud. :whistle:

[alexk]

Neil the electric fan cannot sit in air...
The fan shroud is used to keep it into place.

[Neil M]

Ha, ha, I said I was no expert! :hahaha:

[Mike R]

Neil was going to use his patented sky hooks ;).

[mattCSLnut]

Neil was going to use his patented sky hooks ;).
... or nail it in place with a glass hammer :clown:

[alexk]

Is anyone having an electric fan instead of the clutch fan?

[stevenEK9]

Is anyone having an electric fan instead of the clutch fan?

finally finished the new setup on my M3

brand new genuine bmw water pump
brand new genuine bmw thermostat
50/50 coolant/water mix with genuine bmw coolant
both oem fans removed
16" slim fan wired in, powered by the oem auxiliary fan controller
triple core full aluminium fluidyne/tms radiator
samco hoses (mostly as mine were feeling a bit tired)


couple things to note

- no shroud fitted as the fan is only really there to pull air through on idle and low speed traffic, which it does a good enough job of without a shroud
- centre air scoop removed as the airbox takes a direct feed from a CSL rep bumper using the oem csl ducting


been running the car with the digital coolant readout in service mode just to keep an eye on the temps and so far so good. heading to the ring in just under 2 weeks for DN10 so will see how it goes then, cooling system took a whopping 9 litres to fill from empty with the new radiator :smt120


fan controller relocated to under airbox

http://img.photobucket.com/albums/v212/hawyziee13/FF254D4F-8C0B-47FC-953B-0FF4F3E1F6E0-264-0000003144C2CCA7_zps551885c4.jpg (http://smg.photobucket.com/user/hawyziee13/media/FF254D4F-8C0B-47FC-953B-0FF4F3E1F6E0-264-0000003144C2CCA7_zps551885c4.jpg.html)

engine bay as it is now

http://img.photobucket.com/albums/v212/hawyziee13/B7B83945-F47A-4DF4-8F67-8FA561441FB4-264-000000312FF94C33_zpse12a4626.jpg (http://smg.photobucket.com/user/hawyziee13/media/B7B83945-F47A-4DF4-8F67-8FA561441FB4-264-000000312FF94C33_zpse12a4626.jpg.html)

http://img.photobucket.com/albums/v212/hawyziee13/1F9F9670-A9DB-420A-A5CF-561181398D29-264-000000312A504FFC_zpsc29bc8aa.jpg (http://smg.photobucket.com/user/hawyziee13/media/1F9F9670-A9DB-420A-A5CF-561181398D29-264-000000312A504FFC_zpsc29bc8aa.jpg.html)

[alexk]

What brand/type is your fan ?

[stevenEK9]

What brand/type is your fan ?

here you go, lifetime warranty and rated to 1850cfm

http://www.mishimoto.co.uk/mishimoto-accessories-16-inch-fan.html


PERFECT size that you can drill a couple small holes in the top and bottom 'lip' of the radiator and it will bolt straight up :beer:

[alexk]

I just saw the specs and the power is only 120W.
That's very low.

My Z4 35is has a 600W fan and my M5 a 1000W.
The 120W sounds like a hairdryer :smt108