03 GMC Savanna 1500Confussed on thremostate replacement?

I haven’t driven this van on the street for a few years, I do start it about every 4 months an move it around a bit.

I wanted to drain an replace the antifreeze, drained though the lower rad. Hose couldn’t find a drain petcock. After refilling w/ plain water for a rinse, after she reached operating temp. the temp. continued to go up.

Turned her off .

So I’m thinking maybe the thermostat is ruined.



How do I know what thremostate she needs?

1. I assume she needs thremostate built into the housing?

Evidentaly the water pump has been reengineered an referred to as late model.

2.so how do I know if the water pump is late model or orginal?like is a casting # ingraved on WP?



I see a few different choices in tempature ranging from 160/187

3. is temp a personal choice?



4.can I test the thremostate be tested by boiling in water to see if it opens then closes after cooling down?



03 GMC Savana 1500 5.3 V8.



https://www.rockauto.com/en/catalog/...hermostat,2200

thanks for advising

 

@the Brain ... my $0.02

• Are you sure you go all of the air out of the cooling system? If there is an air pocket, you may not be getting good flow. I own one of the cheap Coolant Funnel Kits (link below), and have used it a million times on all of my vehicles. The big funnel sits on a tube sticking up out of the radiator (replaces the cap temporarily) so the coolant is at the highest point in the system. Then you run the engine, rev it a few times, get it up to temp, etc and all of the air will bubble out and be replaced by coolant. I would certainly recommend trying that before dorking with the thermostat or water pump
• You could take the thermostat out and run without it just to (a) prove that the water pump is still working [visible by removing the radiator cap and looking down into the radiator] and (b) seeing if the thermostat is in fact bad [yes, you can boil it and measure the temperature at which it opens ... you have to watch it while it's in the boiling water]. Once you measure the temp at which it opens with a thermometer you will know what you have, 160 / 180 / whatever.

W89740 - Spill Proof Coolant Funnel Kit - Performance Tool
https://wilmarllc.com/w89740/w89740-...ant-funnel-kit