I have a 2000 chevy silverado 1500 it overheated the other day. I noticed that i was not getting any heat. the engine temp was normal. I started to drive down the street and the heat went into the red. I shut it off and let it cool down. I was think it could be the thermostat so I replaced it and it seemed to run fine. drove at normal temp and I had heat again. Now I went outside and saw a puddle under the engine? It may be the water pump after all? Would I still have heat even with a bad water pump?

 

Bad water pumps leak but usually continue to pump coolant so heater should work. If coolant's from pump should be able to see it coming from the pump.

 

It's coming from the back of the pump it looks like. Kind of hard to tell exactly where it is coming from. Very slow drip did not find a very large puddel

 

Yup, very likely the waterpump.

 

I'll bet your pump slowly leaked enough coolant to cause your original problem. You changed the 'stat and I assume you then topped off the fluid level. Sounds like it's time to change out the pump or you will see the same problem again.

 

Yes going to change the water pump today. Was hoping the thermostat would be a quick fix. Never any such luck. LOL I am on the east coast and getting slammed with snow right now. I do have an Unheated garage so that is a good thing i'm not outside.