Bad water pump?

To me at least that sounds like a bad unit. Out of curiosity where did you get it?
I hope theres a warranty.

Bought it from rockauto.com. Was only about $20 so I'm debating on whether it'd be worth having to send back since shipping will run about $10 on it.

You are right....5 minutes of run time shouldnt kill a water pump.

My question IS:

Did you have coolant in the engine and radiator....up to the bottom of the thermostat, before start up?

If you forgot and cranked it and had not filled the radiator....the water/coolant may not have been at a pumpable level and it could have burned up the shaft seal....That is WHY waterpumps fail....shaft seal leakage....either from heat....or age.= weep hole leakage.

:read2:
Hmmm thats a very interesting thought.

I filled up the radiator before starting the engine but after it ran the level dropped off and I had to add another half gallon to gallon (dont remember exactly).

I can't say for certain if it reached up to the thermostat or not...how would I without physically removing it?
bad pump in my opinion it really dont matter where you got it because most rebuild shops only repair whats wrong and it sounds like yours may have been shipped to fill qouta good luck on next one

The pump was a brand new unit not rebuilt.