The no guess way to diagnose blown head gaskets.

There is definatly a way to find if you have blown head gaskets, commonly occuring as a compression in coolant condition, where you will see bubbles in the coolant overflow tank. Usually, the engine will continue to run very well, and its usually not discovered untill the engine begins over that time there is usually alot of activity in the overflow tank..including overflowing of the coolant overflow tank. To find out more on commonly over looked reasons for head gasket failure, see the 5.7l Technical section.

First, let the engine cool down if hot, remove all belts, Alternator, AC, Power dont want the water pump to move when you start the engine. Drain the entire radiator and remove the lower radiator hose from the radiator leaving it attached to the water pump. Remove the upper radiator hose from the thermostat housing and remove the thermostat housing...remove the thermostat and place it bottom first into the end of the lower radiator hose and tighten the clamp. Bend up the lower radiator hose upwards. Fill the engine to the top with water through the thermostat housing. Start the engine...since there is no water pump moving, there should be no water activity, besides movement from the engine vibrations. If there is bubbling or spitting from either side, then that side has a blown head gasket. Note, that at around 200 Degrees Ferenheight, the water will begin overflowing since it is near boiling. Dont run the engine for more then a few minutes, you will be able to notice bubbles after a few seconds..if there is no bubbles, there is no compression in the coolant. Remember, when you run the engine, there is no water pump moving..the engine can overheat if it remains running for more then a few minutes.