Hello,

Got a concern about my 2000 XJ. Its very hot on the west coast at the mo and using the a/c for the first time in the 6 months I had the XJ. Blows nice and cold, running temp goes up a little bit while I am driving, but nothing to much (normally runs around 200, this puts it to 210). When I stop the engine though, weird stuff happens. The coolant bottle fills up nearly to the top with very hot coolant fluid. I can hear a slight hiss from around the radiator cap, and the engine temp goes right up to max. After 20 mins or so its cooled down again. Now I know its v.bad to overheat XJ's, especially of this year, so I am wanting to fix the problem. Any thoughts other than, don't use the a/c?

Thanks

 

What has been done/replaced with regard to cooling system maintenance?

 

While I have owned it, not much. Had a fluid flush done after I bought it.

 

Really would love some help. Please?

 

sounds like a loss of pressure somewhere in the system casuing the water to boil and run to the overflow. I had this exact same issue recently and it turned out to be pinholes in the rusted metal pipe that runs out of the water pump. I could see coolant pooling in the A/C compressor mount where it was spaying our under pressure.

 

Replace your radiator cap, they're like $5 at the most. When the spring wears out it allows the system to boil over much easier. Make sure you buy the correct PSI rated cap, I think it is 16lb for the 4.0.

 

+/-$250 in parts replaces the entire cooling system (radiator, water pump, fan clutch, tstat, etc.). Replacing everything virtually eliminates the guessing and means u only have to drain/refill cooling system once.