Coolant tank almost empty

[wayne36]

I have a 2004 1500 silverado 160k miles and I have never had problem with it before but today I was out in town extreme coolant temp came on and the temp was pegged out I get out and check and the tank was almost empty it took almost a whole gallon to refill. I have never seen any leaks or over flows. Do I have a cracked head or a bad head gasket?

[newdude]

Is it a 5.3? Some of those had the Castech casting issue.

[kstruckcountry]

Have you ever changed or filled the coolant? Believe it or not some disappears over time.

[wayne36]

The engine has a fan and my rad is a sealed one mean it doesn't have a rad cap. topped it off again ran it up to temp for 10 mins with a new coolant tank cap to if anything happens over night as in leaks.

[wayne36]

Yes it is a 5.3 and I refilled it at last oil change, I just checked it and it 1" low sense top it off.