I know this isn't a Chevy forum but I also know it is full of good mechanics. Looking for some help with my 07 Chevy Silverado Classic. It has the 4.3L V6 with automatic transmission and has been bullet proof for all 51K miles. She recently threw a code which, according to the dealer, indicated my thermostat had went bad. Dealer wanted to charge me 200 to change the thermostat, I told him I would do it and paid 21.00 for the part. I did have the dealer change the oil while I was there. Anyway, that was a couple of weeks ago and I haven't changed the thermostat yet figuring, since the truck has never run hot that either it wasn't a problem or the dealer was wrong. Well, the check engine light came back on today. I started looking around under the hood, figuring I would change the thermostat tomorrow. How shocked was I to discover there is no radiator cap, or at least not one that I can find. The top of the radiator is covered by a plastic shield. While underneath the hood I checked the overflow jug, it was bone dry, no coolant in it at all. I filled the jug and drove the truck to dinner (10 miles round trip). Got home and checked, the jug was about half full. There is no apparant coolant leak, I checked all the fittings, hoses and everthing. There is no smell of burning coolant and no water in the oil that I could tell. My questions, anyone know where the coolant might have went? and does anyone who owns this model/year know how to check the coolant level? thanx.