Fan Clutch Not Working Properly

[Earing2008]

Hi All,

I've noticed on several occasions that my fan clutch is not working properly causing the fan to spin at max speed with engine and each time engine temp has been at or below operating temp. So far it has not caused problems and has gone away with an engine on/off cycle but I don't want to get stuck driving XX miles with the fan at max because its very annoying and sounds like its going to come apart. Is this a common Rover problem? Should I just bit the bullet and have my dealer replace it?

2008 LR3; 38K miles, extended warranty

 

[Trynian]

I would not say it is a regular common problem but I have heard of a few needing to be replaced.

If I understand things right, the fan clutch does engage when the engine is cold to help warm up by putting resistance on the engine.

It is controlled by the Engine Control Module (ECM) that regulates the clutch based on input from the coolant, ambient and transmission oil temps. So there is a chance that is is not the actual clutch but could be a sensor causing the ECM to engage it.

 

[Earing2008]

I would not say it is a regular common problem but I have heard of a few needing to be replaced.

If I understand things right, the fan clutch does engage when the engine is cold to help warm up by putting resistance on the engine.

It is controlled by the Engine Control Module (ECM) that regulates the clutch based on input from the coolant, ambient and transmission oil temps. So there is a chance that is is not the actual clutch but could be a sensor causing the ECM to engage it.

Thanks for the info Trynian. I had to think about that one for a bit but with the use of the radiator thermostat I guess they could increase fan speed to warm up the engine. However, I've looked at my fan clutch and I can not see a sensor/wiring therefore I don't understand how the ECM could have any controlls associated? From the looks of it mine would have the simple internal thermostat which increases fan speed based on increased air temperature.

 

[bbyer]

afraid trynian is correct

Below is roughly how the electro viscous fan operates. In other words, the fan is not the same viscous fan sitting in front of a GM 350 on your pickup of the nineties.

It is more of this Pulse Width Modulated signal stuff, just like what controls the regulator in the alternator where instructions are taken from the engine computer.

Electro Viscous Fan Operation Theory

The temperature of the cooling system is monitored by the ECM via the Engine Coolant Temperature (ECT) sensor located in the cylinder head. The ECM uses signals from this sensor to control the cooling fan operation and adjust fuelling according to engine temperature.

To control the cooling fan, the ECM sends a Pulse Width Modulated (PWM) signal to the cooling fan module (integral to the ECM). The frequency of the PWM signal is used by the cooling fan module to determine the output voltage supplied to the fan motor. The ECM varies the duty cycle of the PWM signal between 0 and 100% to vary the fan speed. If the PWM signal is outside the 0 to 100% range, the cooling fan module interprets the signal as an open or short circuit and runs the fans at maximum speed to ensure the engine and gearbox do not overheat.

The ECM operates the fan in response to inputs from the ECT sensor, the transmission oil temperature sensor, the A/C switch and the A/C pressure sensor.

The speed of the cooling fan is also influenced by vehicle road speed. The ECM adjusts the speed of the cooling fans, to compensate for the ram effect of vehicle speed, using the Controller Area Network (CAN) road speed signal received from the Anti-lock Braking System (ABS) module.

I would be interested in hearing your eventual solution to the problem as I installed a new electro viscous fan a few months back and now I seem on occasion to be having the loud noise sometimes problem again.

 

[AlaskaKaz]

Bump. Has anyone else experienced the intermittent cooling fan stuck ON with their LR3? I can't find a fault code with my IIDTool, but have noticed that sometimes it was showing 0 (zero) on the viscous fan speed, yet clearly turning with the engine RPMs and roaring loudly. I don't want to start a shotgun approach to diagnosing with replacing random parts. Any help would be appreciated.

 

[Houm_WA]

Weird $hit but I'm pretty sure it's normal. I mean...it can be stuck on for a while (like 30 sec maybe) but eventually it turns off. So, what do you mean by "stuck ON?"

 

[thorgal]

I had a fan operating at max RPMs few years back,it just would not stop after start,roaring,then i remembered reading on the forum , that Relay could be at fault .i obviously had one spare in the boot, 40 amp and as my wife was getting nervous on the passenger seat, I pulled the old one from the engine bay installed a new and problem immediately disappeared,never to surface again.
Sometimes it is the simple things that you got to start with.
Over the years I have developed a immunity to anything that goes around my LR3 as I have learned a LOT and don't panic anymore, if any hiccup happens during a long of a short drive.Start with a simple solution and you may find that it is usually a proper one.Good luck

 

[bbyer]

What relay?

I had a fan operating at max RPMs few years back,it just would not stop after start,roaring,then i remembered reading on the forum , that Relay could be at fault .i obviously had one spare in the boot, 40 amp and as my wife was getting nervous on the passenger seat, I pulled the old one from the engine bay installed a new and problem immediately disappeared,never to surface again.
Sometimes it is the simple things that you got to start with.
Over the years I have developed a immunity to anything that goes around my LR3 as I have learned a LOT and don't panic anymore, if any hiccup happens during a long of a short drive.Start with a simple solution and you may find that it is usually a proper one.Good luck

I have to agree with not panicking when a light goes on or a noise starts - that just seems part of the LR mystique - well maybe mystery.

As to mystery, the relay you refer it, it is apparently in the engine compartment fuse box but which one? I looked thru the viscous fan wiring diagrams and about all I could find is some reference to a solenoid, N104, and Hall effect Sensor, T263, both collocated somewhere, plus a 15 amp fuse, F10E in the engine compartment fuse box.

I have the intermittent problem - that is the engine cooling fan runs for longer than usual upon startup - well it keeps running at full speed and will not fall back, but at next shutdown and engine start, all is normal again.

I find that this only seems to happen in conditions of high humidity - not necessarily on a rainy or foggy day but more often when rain or fog seems imminent.

Yes, the high speed on for say 30 seconds is normal at first engine start when cold. It is something to do with pollution controls - to load up the engine at initial cold start so the engine does a bit of work and hence meets pollution standards. Once the engine is warmed up, the fast fan function is not needed for subsequent starts.

Anyway, to you recall which relay you replaced? I will probably do the same as most of my relays are still all original and I also carry spares.

 

[thorgal]

It was F16 40 Amps that i replaced.

 

[bbyer]

a fuse I gather, F16

I noted a sort of light bulb icon beside the F16 fuse. I have always wondered what that light bulb like icon was supposed to mean.