Thanks CE for your response. The cooling fan clutch is working properly.
Flushing the system.
First, I drained all the coolant out of the radiator.
Second, I removed the radiator cap and the drain plug at the bottom. Using
a hose and with the engine idling I let the clear water run thru the
Third, I replaced the radiator cap and drain plug. With the engine running
i let the clear water pump thru the system. I then turned the radiator cap
to the first notch to release the pressure.
Fourth, using the hose i flushed out the coolant resevoir, until i was
getting nothing but clear water.
Fifth, I filled the resevoir with 50/50 coolant to the "Cold Fill Mark".
Then I filled the radiator with 50/50 coolant.
It did not resolve the problem. As soon as I started the engine, the gauge
went to straight to HOT and remained there. I drove the truck about 10
miles at speed from 40-70 mph. I shut the engined off and waited til the
engine cooled and drove back another 10 miles...Same problem...the heat
guage stayed in the HOT zone.
Verifying the water pump is actually moving water. I removed the hose
coming from the block and clean water came thru when I flushed the second
time. The truck overheats as soon as I turn the ignition on and start the
engine. At rest and when the engine has cooled the gauge does move up
barely into the normal range on the Hot side of the guage. Now, SOMETIME,
(and rarely) the needle will move up into the normal range on the high end
of the HOT side.
It has never boiled over, UNLESS I turn the a/c on.
I think I have answered your questions and hope they will give you a
better insight to my problem.