Cooling fans is it me or are they running too often...

[Zippyworld]

Despite the hot weather I am convinced the cooling fans on my X308 XJR sem to be running a lot, its not constant but they are on an awful lot, any ideason this chaps ?

Secondly, the leather on the steering wheel is starting to wear where I rest my hand whilst driving, anyone got an idea of what I could apply to help preserve this ?

Thankyou

[Kawasicki]

You've got a powerful car, cooling it on a hot day takes some effort.

[P700DEE]

Classic sign of a failing thermostat. Do they run after you switch off ? Note they run single speed if you use the aircon, it is unusual to run double speed except in this weather in traffic.

[Zippyworld]

This is whats odd, it has a new thermostat and temp sensor. I did say despite this hot weather !

[Zippyworld]

P700DEE said:

Classic sign of a failing thermostat. Do they run after you switch off ? Note they run single speed if you use the aircon, it is unusual to run double speed except in this weather in traffic.

It does run on after switch off, it stops briefly when i turn the ignition off and then almost instantly starts again.
This is with aircon off but to be honest I didnt check if both were running...

[Zippyworld]

I am wondering if there is a link with it needing 400ml water coolant topping up today ?
It was topped up 500 miles ago.

I never did find the cause of it ripping the auxillary belt up, but a second new belt and it seems to be behaving, does the belt go around the water pump ?

[P700DEE]

Yes the auxillary belt does drive the water pump.
The temperature guage is nothing more than a damped switch that operates between cold, normal and engine destroyed. You need to get the real temperatures read quick, a simple bluetooth OBDN reader and a phone app are enough to give you a read out. You may have a failing water pump it could be a duff new thermostat. The water loss could easily be some water boiling off , this is very bad for our cars Aluminium engines do not like excess heat , head gasket failure is very common if your engine gets too hot!

[Zippyworld]

Thankyou for the input, I will see where I can track down a reader in the UK.

[melhookv12]

Did you use a Jaguar temp sensor?

I looked at a car for someone whos fans were running high speed more than they should. His thermostat and water pump and temp sensor had all been replaced. Not sure what the orginal fault was, I visually inspected the pump and tested the thermostat, all ok, I had a used Jaguar temp sensor, fitted this and all was ok. The thermister sends signal to ECU and therefore controls the fan.

So the non jaguar sensor was sending incorrect signals to the ECU.

[Zippyworld]

melhookv12 said:

Did you use a Jaguar temp sensor?

I looked at a car for someone whos fans were running high speed more than they should. His thermostat and water pump and temp sensor had all been replaced. Not sure what the orginal fault was, I visually inspected the pump and tested the thermostat, all ok, I had a used Jaguar temp sensor, fitted this and all was ok. The thermister sends signal to ECU and therefore controls the fan.

So the non jaguar sensor was sending incorrect signals to the ECU.

I think I may have a non genuine part, it came from David Manners and I cannot remember.

Its good advice so I will pick one up just to be sure. Thanks

[Zippyworld]

Zippyworld said:

melhookv12 said:

Did you use a Jaguar temp sensor?

I looked at a car for someone whos fans were running high speed more than they should. His thermostat and water pump and temp sensor had all been replaced. Not sure what the orginal fault was, I visually inspected the pump and tested the thermostat, all ok, I had a used Jaguar temp sensor, fitted this and all was ok. The thermister sends signal to ECU and therefore controls the fan.

So the non jaguar sensor was sending incorrect signals to the ECU.

I think I may have a non genuine part, it came from David Manners and I cannot remember.

Its good advice so I will pick one up just to be sure. Thanks

Put a genuine Jaguar part in and hey presto, its working as should be ! Thankyou for your help.

[melhookv12]

Good to know that cured it. Pattern parts are ok most of the time but occasionally they are sub standard. You could of been chasing that fault for quite a while if assuming temp sensor was good and working correctly.