2010 Silverado overheating... any ideas?

I have a 2010 Silverado with a 5.3L Z71 that keeps overheating. I replaced the thermostat, and it runs fine for a while, but as soon as I turn it off and get back in, it overheats again. When I open the lid, it spews out some fluid. If I add some coolant back in and keep the lid off, it runs cool again until the next time. It’s a bit frustrating, lol. Any advice would be greatly appreciated.

Are you getting constant heat in the truck? That might help narrow it down.

Lake said:
Are you getting constant heat in the truck? That might help narrow it down.

Yeah, the heat seems consistent while it’s running, but it definitely overheats when I stop.

Wiggle the water pump pulley and see if it moves in and out. Also, check underneath it for any dried lines of coolant.

Vero said:
Wiggle the water pump pulley and see if it moves in and out. Also, check underneath it for any dried lines of coolant.

I haven’t checked that yet. I’ll give it a try and see what I find.

It sounds like you could have a blockage somewhere in the cooling system. Have you flushed the radiator recently?

Sloane said:
It sounds like you could have a blockage somewhere in the cooling system. Have you flushed the radiator recently?

Not recently, but maybe that’s something I should consider. Thanks for the suggestion.

Have you checked the coolant level? Sometimes it might just need a top-off.

Jordy said:
Have you checked the coolant level? Sometimes it might just need a top-off.

I did check it, and it seems fine, but I’ll keep an eye on it.

If it keeps overheating even after replacing the thermostat, it might be worth checking for a failing water pump too.

Winslow said:
If it keeps overheating even after replacing the thermostat, it might be worth checking for a failing water pump too.

I’ll look into that as well. It sounds like it could be a few different things.