2000 XK8
Lately, I've noticed the smell of coolant when I pull into my garage. I checked the level - and found it full. There are no visible leaks. The heater blows hot. and at an idle, I can hear the fan turn on and off. I replaced the plastic thermostat housing as well as the thermostat in the spring and didn't have any issues in the warm weather, i.e., no overheating etc. HOwever, now that its cold out, I noticed that the hose going into the thermostat is hot while, what I'm assuming is the large "exit" hose is cool. Does this sound like a water pump issue or more like a stuck thermostat? Any ideas appreciated. THanks

 

seems to me if the WP was shot you would see over heat issues real fast.

 

You could have some degradation of the pump vanes without total loss.If you have no record of the pump being changed, it would be a good idea, anyway. It's not that difficult.

 

I find it unlikely that the thermostat failed to open but a good indicator would be an overheat indication. You said the car did not overheat in the summer is this correct? Does your temperature gauge go to the middle and stay there? As for the heating system it has a separate pump under the car in the transmission well so you have circulation of hot water.

Have you flushed the coolant system when you replaced the thermostat? You may have mixed orange and green coolant that could be a problem, mixing them can cause jelling and cause restrictions. If you did mix them I suggest flushing the entire system and refill. The water pump could be failing but I would think you would have overheated in the summer and the fans cycling leads me to believe you have circulation.

Now for the leak I would suggest that you look under the coolant tank and see if the leak is from it then look at the coolant hoses under it. Any leak in that area will fall onto the exhaust manifold or pipes.

 

If you need to do a pump I am doing mine now and must day for this car being a JAG and all the BS hard to do or get to stuff this pump replacement is the easiest one I have ever done.

 

This is how i did my water pump

Link JagRepair.com - Jaguar Repair Information Resource