06 gxp Running hot

[a2ijonesss]

Hey, I’m new to the group but i already have a question. So i have a 2006 Pontiac Grand Prix GXP 5.3 and it’s been running hot constantly (hot coolant display) for about a week after about 8 mins of driving.Coolant is good. Fans kick on. No obvious leaks from water pump or radiator. Replaced thermostat and coolant temperature sensor but still runs hot. Any advice on what cold be the cause of the issue.

 

[Fivefingerdeathpunch]

What is the sensor saying on a scan tool?

Is it doing a hop skip and jump in temp? Like going up slowly like normal and then just pegging it self hot?

 

[a2ijonesss]

I haven’t tested the sensor itself on the scan tool now when i did scan it, the sensor was the only thing that came up on codes. It takes about 10 minutes of driving for it to run hot

 

[Gregorius]

On a Cold engine, turn the heat on. Pull a heater hose and see if it's gushing out when started. Idea is, is that even with a closed thermostat, there should be strong flow thru the heater core. Unless the "vanes" have all rusted off the impeller on the water pump, which happens. Then you just have a throwing star spinning in the coolant doing nothing.