New LS3 start up but no water flow through radiator

[Vegas69]

Coolant doesn't flow through the radiator until the t stat opens. If you temperature gauge isn't exceeding your t sat opening temp, you aren't running it long enough.

[randy]

yup i freaked out as well. I need up putting about 3 jugs in to finally fill everything up. Just go buy a cheap temp infrared gauge and point it to the thermostat. My guess is you dont have it hot enough yet

[vstol]

Thanks but temp in going past 210 to 240.

[Che70velle]

I wouldn't let it go that hot again. The infrared gun aimed at the tstat will give you an indication of a faulty gauge. If gauge is ok, you have a bad stat, or some kind of blockage, ie a shipping plug left on radiator inlet, etc.
Is the TStat a GM piece? It should open, and you should see water moving in radiator before 210. If not, shut it off.

[Vegas69]

Air pocket if it goes from 210 to 240 quickly.

[vstol]

Originally Posted by Vegas69

Air pocket if it goes from 210 to 240 quickly.

It does and I plan to elevate it tonight or tomorrow to see if I can get rid of it. Understand cap off?? Thanks

[130fe]

I agree with the air pocket diagnosis. Fill the engine through the upper radiator hose, and fill the radiator as well. Never had an issue with air pockets doing it this way.

[Neil B]

Sounds like an air pocket. I've never had that issue on an LS, but my BMW did that after a water pump swap. It took several bleeds to get it fixed.

[vstol]

OOps I meant to close this it was the gauge