Hello to all.

First of all, I am a new Jag owner, and purchased the car literally a week ago.

The car ran perfectly in all respects, with no errors or issues.

As I typically do, I decided to perform some routine maintenance on the car, and changed spark plugs, air filter, and checked all fluids, including the coolant.

IMMEDIATELY after completing the tune up, I went for a test drive. The car overheated within 2 miles of my house.
The gauge went up to the red, and the red light came on.


I immediately turned the heater on full high to help cool the car, and with the heater on, the car cooled enough to be driven back to my house.

Since then, I have been driving myself crazy trying to figure out where the issue lies.

It appears that no coolant is flowing through the radiator. As previously mentioned, the heater works fine, so there IS coolant flowing (so I am assuming the water pump is fine).

I replaced the thermostat, and that did not correct the issue.

Is there anything in the car that may have been 'bumped' during a tune up which would cause this? It is hard for me to accept that the car ran absolutely perfectly until the tune up, and that the two are not related.

Again, as far as I can tell, coolant is NOT flowing into the radiator. Radiator is cold, even as the engine temperature goes past half way. Thermostat has been replaced, which did not correct the issue.

The passenger's side radiator hose gets hot to the touch, while the driver's side radiator hose (and radiator itself) remains cold.

Please, any assistance would be greatly appreciated.[/align][/align]thank you[/align][/align][/align]

 

Wow. A lot of different things could be at work here:

1. Failed water pump
2. Defective thermostat (you have probably ruled this out already)
3. Blockage in cooling system

From what I have learned, it seems that water pump failures on this car are fairly common. The original stock pump has a plastic impeller, which can melt if the engine becomes too hot. The pieces can partially block portions of the cooling system. Also, what is your coolant level after all this? Is there evidence of coolant loss?

I have a '99 XJ8 that I bought about a year ago, and the seller replaced the water pump before the car was delivered due to a leak in the front seal. The replacement pump has a metal impeller.

Good luck. I cannot imagine what could have happened during the tuneup to cause this problem, but it seems a little too much of a coincidence for there to be no connection.

 

Hello.

Thanks for the response.

Unfortunatly, I do not think it is the thermostat, unless the new one I just purchased is also defective.

Could the water pump be at fault if my heat works perfectly? I would assume that if the water pump failed, I would not get any heat either??

Thanks.