overheating issues

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Jul 1, 2007
Erie, Co
I put a 5.3 in my fj62 some years ago and I feel like ever since it has for the most part remained around the same temp on the gauge as the 3fe did, pretty much on that second line up the gauge. It's always had a few very minor leaks here and there on the coolant but not much to worry about.

Recently I tightened everything up, no leaks that I'm aware of, and the gauge climbed one night to between the third and fourth hash on the gauge without me knowing it. Ever since, it seems to run hotter than I would like. It will stay at the normal second line for a while, and then creep up to the third line and kind of stay around that area. On the highway it will initially come back down to the second line and hold, but if i'm really pulling along, it goes back up to the third line or even just beyond.

Since this has been happening, I initially thought it was an idle issue and put on the wonderful ford contour fans. They don't seem to help much.

I know everyone will say the stock temp gauge is notoriously incorrect, so here are my readings with my IR gun.

Bottom hose before tstat - 150ish
Tstat - 180
water pump housing outlet - 210 - 220
radiator inlet from water pump - 200

At those readings, my gauge is pretty much right on the 3rd hash, or what looks like half way. Being that I know this is higher than my tstat is set at, because it cools down to the second hash when I get it going after an idle, i'm worried that it may get worse or under other circumstances get hotter.

My question is, how much hotter would you think your upper rad hose would be than your tstat? My radiator outlet is cooling down to 150 or below, so I know the fan is fine. Does this indicate that the water pump just might not be flowing fast enough and the hot water is staying in the engine too long? Should the radiator inlet hose be closer to the temp of the tstat, or does the 20-30 degree diff make sense, yet it cooling down when initially leaving from idle is normal also?

Hoping it isn't related to the head gasket, have a tester coming in this week.

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