i just spent the weekend camping in the mountains. on the way back the low coolant warning came on, temp on everything was good, just low in reservoir so I continued, not having any coolant with me. No increase in temperature at all. When I got home it would not start again. I added the coolant, it started right up. My question: will it not start when coolant warning is on, or was this just coincidence?
Thanks Norm

I had the same issue except for the not cranking problem. My truck is identical to yours except it's a 3500.
The first 98,000 miles the temp would stay fixed at 210F, Texas hot or Colorado cold. About 4000 miles beyond the first low coolant warning, antifreeze began to blow out the overflow tube. Another 5000 miles later, I got varying temp readings (175F-205F) and soon after the water pump started leaking. Now, 3500 miles (111,000 miles) after I had the new pump and thermostats installed, the leak is fixed, but the temp still varies. I don't have the low coolant warning anymore...I keep the reservoir beyond full and appear to not lose any. I've been told...head gasket, antifreeze reservoir cap, air in cooling jacket after repair and a few others is the problem. I was also told the head gaskets are just about impossible to determine if they're faulity until failure.

Good luck...I've lost faith in this truck.

Sounds like just a coincidence. You don't need to add coolant just distilled water. Go to the grocery store and keep some in your garage.

I've put on about 200 miles since then, coolant level good, temp good. My only issue is why it wouldn't fire up that one time. I'm am going to run it through a GM diagnostic ?????? Reason may show up hopefully. I'm running out of GM warranty. I have another 1000 mile tow coming up on long weekend, something will show for sure.