I am having an overheating problem with my 98 4X4 T100, 160K. It never gets hot while moving at any speed but when idling the temp will begin to creep up. It doesn't happen all the time however. Also sometimes if I shut the motor off and then restart in a few minutes the gauge is almost in the red. It goes right back down when I rev it up to 1500 RPM for a few seconds. I have had the fan clutch replaced but it didn't help. I am about to flush the radiator but my confidense is not high. Any ideas?