My 96 XJ is overheating, and I have replaced the thermostat, water pump, and clutch fan. The electric fan is operational. I did a combustion leak test but there was no combustion gasses found. I checked the tightness of the belts, and replaced the radiator cap. It only overheats after idling a long time, or after driving and when I pull in the drive way it super heats unless i turn the heat on full blast. Please give me suggestions on what else to check/replace/etc. Thanks!!!!!!

 

"Everything" would mean you also replaced the radiator

 

What did the water pump look like when you pulled it? That should give you some insight as to what the radiator looks like, except if the WP was corroded, the radiator is no doubt worse.

 

The lower and upper radiator hoses get hot ... And my symptoms don't exactly point towards a bad radiator do they?

 

The guy that had before me had the water pump replaced so I can't answer that question.

 

Also my coolant is really clean

 

Try the radiator cap!!

 

I replaced the radiator cap

 

Flush the system, then id say if that doesnt work new radiator

 

Air in the system Or clogged radiator

 

could be the wrong water pump, I have seen that happen before.

 

Use 10 min flush bottle, not 3 hours flush

 

I once bought bad fan clutch

 

A solution that I have used before on copper radiators is to take it out and let it sit holes up with CLR in it for a couple days. Poured about a cup worth of deposits out of my old crown vic radiator doing it like that.

 

The problem with CLR is that it works too well.