So here's the story: I was taking my XJ out for a spin since it was years since it's been driven only to be used recently for short distances (like getting groceries and such) and wanted to know what problems it could have from staying still so long. Well to my luck I got my answer because after taking it around the city and then doing 50+ on the highway for about a good hour it began to drag and could tell it was forcing itself to keep the speed constant, up to the point where it even began to wobble or shake (but the tires didn't look like they were the cause). As this happens I see the dash marking over 210 but not near the red zone. When I popped the hood I found the coolant tank exaggeratedly ful as if it were backed upl, coolant gushing out after taking off the filler cap and the motor idling way too high. Now, I noticed the fan never turned on, but I don't think all that could have been possible just from the electric fan not working. Any suggestions? Many thanks for your time.

 

Could be as simple as replacing the cap on the bottle with a 703-1396 from Napa.

 

So the electric fan isn't necessary?

 

It is, but rarely comes on if the system is full and holding pressure.