I've had overheating issues since the day I got the air conditioner fixed. It's a 2001 XJ with a new radiator, fan, sensor, new thermostat, hoses, water pump, head, head gasket, radiator cap, almost in that order. The temperature gauge reads 220, but by the time I get home, and I drive Houston Texas freeways, it's boiling in the overfill. Not boiling over, just boiling. Is that normal? If its overheating then why is the gauge not showing it?

 

No, its not normal. And 220* is high, you really shouldn't be too far above 210*.

And since you have an 01, you have a 0331 head unless that was already swapped. If it wasnt, you should be concerned with the head being cracked.

Was the head thoroughly checked for cracks when the HG was replaced?

 

New fan clutch???? I'd suggest trying another new rad cap and verifying temp with a infrared temp gun pointed at the t-stat housing. The rad cap is a 2 way valve that allows some expanded coolant to flow to the recovery bottle when the motor is at operating temp, then allows coolant to return to the rad from the bottle as the motor cools when off. Check the coolant level, MOTOR COLD......coolant level should be at the top of the neck of the rad, again MOTOR COLD.