Ok let me start at the beginning. One day I was driving to the store about 1mile from my house. I noticed that the smoke was coming from under the hood and the temp was about 245-250 degs. I quickly pulled over popped the hood to inspect. I noticed white smoke coming from the back of the engine. I was low on coolant and my oil was a quart low as well. I filled them both and drove home. I drove home with the ac off so I could listen for any unusual noises, just before I pulled into my driveway I turned on the ac and then my truck died. I notice the water pump was leaking through the weep hole when i got home and parked. Ok so I replaced the thermostat (failsafe) and the water pump. Worked fine for about a week then I noticed it started run a little hot again. Coolant was low again. I filled the coolant again in both the radiator and the reservoir tank. The next day I started the truck and noticed white smoke pouring out the tailpipe. I started driving and within 5 minutes or about .75 miles it stopped. That evening I got home removed the thermostat and found that it had failed in the open position. Oh another thing I forgot to mention is after replacing the coolant when I changed the wp and t-stat I hear a bubbling noise from the reservoir tank every time I turned off the truck. So I bought a gm t-stat to replace again. While I was working under the truck I notice the coolant was leaking on the right side of the engine and could follow it where it was dripping but I can not see where it is originating from, it is not coming from a hose or a connection from what I can tell. I don't see any oil in the coolant and I don't see any coolant in the oil. The leak seems to be on the engine it self. Is this possible? I am also experiencing rough starting and it sounds like it is sputtering when I first start it up. I give it some gas and it sound better. I change the plug, wires, and coil packs with no improvement. Any ideas as to what is wrong? Please help me.