Radiator fan running constantly and fix

[SOLIDM4]

Originally Posted by m2ruder

Sport + the fan runs 24/7 also..... supports the increased track cooling capacity

Mines runs even efficient mode after I installed my Downpipes mind you I'm completely straight Pipe.

[Vlad_T]

Originally Posted by SOLIDM4

Mines runs even efficient mode after I installed my Downpipes mind you I'm completely straight Pipe.

I have same issue with fan after replacing the a/c condenser on my F80. Going to fill a/c today, hopefully fixes it!

[jagus]

wow, good to know, thanks for sharing!

[ninekrpm]

My M is a track car, all the AC components are removed amd the runs at all times. It is kind of annoying…wonder if this can be coded to bypass the AC and run as temp rises.

[GuyLedouche]

Originally Posted by ninekrpm

My M is a track car, all the AC components are removed amd the runs at all times. It is kind of annoying…wonder if this can be coded to bypass the AC and run as temp rises.

I’ve been trying to figure out why my fan has been running non stop after I deleted my AC. Did you find a solution to this? The one thing I noticed is that the fan only runs when the HVAC is turned on, in my case 84 degrees on lowest fan speed for coolant bleeding.

[ninekrpm]

Originally Posted by GuyLedouche

I’ve been trying to figure out why my fan has been running non stop after I deleted my AC. Did you find a solution to this? The one thing I noticed is that the fan only runs when the HVAC is turned on, in my case 84 degrees on lowest fan speed for coolant bleeding.

Have not found a solution, deleting the AC caused this, mine pretty much runs at all times.

Have thought about replacing the fan, factory fan is very heavy.

[GuyLedouche]

Originally Posted by ninekrpm

Have not found a solution, deleting the AC caused this, mine pretty much runs at all times.

Have thought about replacing the fan, factory fan is very heavy.

I did find the cause. The fan is running because it thinks the AC pressure is high. I'm sure there's a way to trick the system by running .5V to the signal pin.

[ninekrpm]

Originally Posted by GuyLedouche

I did find the cause. The fan is running because it thinks the AC pressure is high. I'm sure there's a way to trick the system by running .5V to the signal pin.

Very nice, totally makes sense…wonder if this can be coded.

[GuyLedouche]

Originally Posted by ninekrpm

Very nice, totally makes sense…wonder if this can be coded.

Problem solved. For some reason I thought that pressure reading was coming from the compressor but it is from a screw in pressure sensor on one of the lines I removed. I pulled that sensor out and plugged it back into the car and everything works fine now. No fan spinning and I am able to bleed the charge coolant system again. I’m not sure what else changes with the sensor missing but I would recommend doing what I did.

[ninekrpm]

Originally Posted by GuyLedouche

Problem solved. For some reason I thought that pressure reading was coming from the compressor but it is from a screw in pressure sensor on one of the lines I removed. I pulled that sensor out and plugged it back into the car and everything works fine now. No fan spinning and I am able to bleed the charge coolant system again. I’m not sure what else changes with the sensor missing but I would recommend doing what I did.

OMG! You rock…

Which lines? Can you share a pic of the line / screw?

And what do you mean, bleed the charge cooling system?

[GuyLedouche]

Originally Posted by ninekrpm

And what do you mean, bleed the charge cooling system?

Ignition on, parking brake set, headlights on, heat on max hot with fan at lowest speed, press throttle for 6-8 seconds and the car starts a self bleed mode for the low temp side. Set a timer and the car doesn’t do anything for 6 minutes then the pump cycles on and off. Works good.

[GuyLedouche]

Pics of the sensor and where it came from. Connects just forward of the driver side strut tower.

[ninekrpm]

Well…I don’t have any of the AC equipment/compressor/blower/etc. or the control panel.

Not going to work me

[GuyLedouche]

Originally Posted by ninekrpm

Well…I don’t have any of the AC equipment/compressor/blower/etc. or the control panel.

Not going to work me

Buy a new sensor?

[ninekrpm]

Originally Posted by GuyLedouche

Buy a new sensor?

Let me make sure the wiring is still there

[GuyLedouche]

Originally Posted by ninekrpm

Let me make sure the wiring is still there

Good point. 😂

[ninekrpm]

In a similar vein, do you know or how would I determine what triggers the charge air radiator water pump?

Is it a temp sensor, if so, what’s the temp?

Is it on at all times? If so, how do I confirm?

Does it have any correlation / connection to the AC equipment?

I ask, as I sometimes feel that the pump is not running. I am trying to figure out its operations and what triggers it.

[GuyLedouche]

Originally Posted by ninekrpm

In a similar vein, do you know or how would I determine what triggers the charge air radiator water pump?

Is it a temp sensor, if so, what’s the temp?

Is it on at all times? If so, how do I confirm?

Does it have any correlation / connection to the AC equipment?

I ask, as I sometimes feel that the pump is not running. I am trying to figure out its operations and what triggers it.

he electrical coolant pump works according to the principle of a centrifugal pump. The coolant pump is integrated in the cooling circuit (low temperature) and is used for the charge air cooling. Communication from the coolant pump to the engine control is effected via local interconnect network bus. The speed specification and the read-out of the current pump speed, as well as other pump values, are realised.

The following values are used for the activation:

Ambient temperature
Difference between charge air temperature and ambient temperature

The coolant pump receives the setpoint value specification via local interconnect network bus from the engine control. The following pump values are reported back:

Current engine speed
Power consumption
Voltage
Temperature of evaluation electronics
Fault status

Characteristic curve and setpoint values

The coolant pump works in the engine speed range of 24 to 6000 rpm. The permissible coolant temperature is between -40 °C and 128 °C.

[ninekrpm]

Originally Posted by GuyLedouche

he electrical coolant pump works according to the principle of a centrifugal pump. The coolant pump is integrated in the cooling circuit (low temperature) and is used for the charge air cooling. Communication from the coolant pump to the engine control is effected via local interconnect network bus. The speed specification and the read-out of the current pump speed, as well as other pump values, are realised.

The following values are used for the activation:

Ambient temperature
Difference between charge air temperature and ambient temperature

The coolant pump receives the setpoint value specification via local interconnect network bus from the engine control. The following pump values are reported back:

Current engine speed
Power consumption
Voltage
Temperature of evaluation electronics
Fault status

Characteristic curve and setpoint values

The coolant pump works in the engine speed range of 24 to 6000 rpm. The permissible coolant temperature is between -40 °C and 128 °C.

very insightful, so basically...it will never run when the car is just running/on standing still


regarding the engine fan, I am tempted to replace it with a spal or similar with a temp sensor/switch. the oem fan is over 30 #'s...so reducing that weight is a motivation