Removed Thermostat- Coolant Flush Hot

[44SAA]

Performing a coolant flush and removed the thermostat. After bout 5 minutes the temp gage on the truck was pegged in the danger zone. Am I missing something? Will idling without a t-stat cause high temps? Interestingly when I removed the peacock the water was cool. Upper rad hose was scalding hot. Confirmed water was moving inside the rad as well. Thank you

[Dead Parrot]

With no t-stat, should have a LOT of water flow. Hot on top of radiator and cool on bottom is what you want if other things are good.

Possible you have some trapped air. If you can, get the front of the truck pointed up a hill.

Also possible the gauge is off. If you have one of those IR 'laser' temp gauges, check with that.

[44SAA]

Thanks Parrot- my water pump may have gone kaput….

[blazer2007]

I would say trapped air ,mine did this last year when putting in a new rad, would get hot pretty fast on the gauge but nice and cool on the bottom

[Corts60]

Originally Posted by blazer2007

I would say trapped air ,mine did this last year when putting in a new rad, would get hot pretty fast on the gauge but nice and cool on the bottom

X2. You have an air bubble

[44SAA]

New radiator is giving me fits. Spent entire day working on it w no joy. I currently have the t-stat removed as I started a flush. Couple things I noticed:
1) topped off multiple time w water, parked truck up hill to assist purge, block is full of water
2) upper hose gets hot.
3) heater used to be blast furnace, no longer gets hot
4) spent all day bleeding air so don’t think that’s problem
5) temp gets to 1/2 way point, and stays there. Then temp gage will peg far right
6) would putting the t-stat back on possibly cure my ills?

Thanks

[44SAA]

Pro tip- don’t forget to remove the plug that comes with the rad- may prevent circulation……….