Hi All,

I noticed the other day the engine Fan kept kicking in even when I just opened the car door. I investigated the water res and found it was sitting below min. I thought odd I added only small amount of water to raise it to max again. Took the car a short trip parked. When I returned to the car same again, when I reversed back there was a small patch of water about the same as I'd put in at a guess.

So for me its not like its pouring water out in total which I had when the water pump was replaced last year. I'm thinking perhaps a lose fitting hose... maybe they did not tighten it enough when they put the new pump on.

Any ideas - car runs fine but obviously I don't want to drive it like this and I just wanted to be clued up before visiting the garage who fitted the pump a year ago and only 4k ago roughly.

thanks

 

Wipe it up with a white paper towel. Is the liquid clear or pink colored? If it is clear it is probably from the A/C. Don't worry about it. Colored - start searching for coolant leaks.

 

Obviously you'll need to find the coolant leak first as it would most likely be the cause of the fan running. The fan speed is controlled by the ECM which monitors engine temperature. The fan control module is part of the fan. I don't know if the fan module fails if the fan will keep running. If that is working correctly then the ECM is seeing a engine temp sufficient enough to turn on the fan. So find the leak 1st . Also what was the outside temps when this happened and how hard did you run the car.

 

I'll have to try the towel. It's very mild here 5-10 degree's at most. I had only been out for a short trip and not pushed it hard at all. As I say weird thing for me is that the fan will start when I just open the car door, even though its been sat idle.

 

If you leave the car overnight and get into it in the morning does the fan start to run. Did you check the OBDII port for any codes. Also what is the voltage of the battery. If the fan control module is OK then the ECM must be seeing a over temp from the engine temp sensor. If that sensor is bad then it should have a code. But once again check the battery for 12.6 volts at rest.

 

Forget about the fan for now... what color is the fluid?

 

Hi all,

thought I'd pop an update the leak got a lot worse and it was orange coolant coming out. I had it recovered to the local independent jag specialist to find out that the aux supercharger radiator had blown. So I've had that replaced, annoyingly though I've got it back and the fan still kicks in and stays on constant, interestingly it only comes on when you open the drivers door and does not when you open the passenger door.

I'm going to fully charge the battery today as its obviously not been able to get to full, mainly given the fan constantly has been drawing off the car even with the engine off. It does stop once I lock the car though.

I'll take it back to the garage as they seem to think it might be a wiring fault?

car runs fine but sounds like an aeroplane (or airplane)

 

On my '07 the fan control wiring got mangled and once the fans was no longer talking to the car it ran full tilt once I started the car but shut off once it was turned off. Under normal conditions the fan will run after shut off if the temps are overly hot.

Possibly on the 5.0's they changed the control logic to power up the fan when the driver door is opened and it's not happy with the communications which causes it to run. I do wonder if hot coolant hadn't gotten in the connecting plugs causing comm issues? On the 4.2 XKR they are right next to the air filter where coolant would splash / spray from the radiator...