What is wrong with my truck?

Stop leak products cause more problems than they fix! They clog up the cooling system passages in the engine and the heater core. Pressure test the cooling system. With the engine cold and the cooling system under 15 PSI, start the engine and look at the needle on the pressure tester. If it bounces, you have a blown head gasket. The only stop leak product I have ever personally seen work, without messing up the cooling system is Blue Devil. But you must follow the directions on the bottle exactly! Even then, remember, it's only a temporary Band Aid fix! To get the engine to crank, remove the spark plugs and try cranking it. If one or more of the cylinders has coolant in it the engine will not crank. The liquid can't be compressed. Removing the spark plugs will allow the engine to crank. If you see coolant squirt out of the cylinders through the spark plug holes, you have a blown head gasket. Hope that helps! Jim

That should have said with the cooling system under 15 PSI of pressure! Sorry!!