My trans am was running rough at idle steam and water coming out the tailpipe water in oil and exhaust smell in rad and high pressure in cooling system. I ordered bears tru blu, followed the directions, pulled the thermostat and put the product in. Started the engine and in one hour minutes no steam or rough idle. Took for a half hour drive at hwy speed and let cool for an hour and did the same drive again.
Ended leaving in the engine for two weeks before putting the thermostat back in and flushing and filling with the antifreeze. They said to use truck is running great engine light off. That is telling me that no water or anti freeze passing the oxy sensor in the exhaust, no water loss at all. The stuff works. Tried other stuff no luck. If you think you have a crack or head gasket problem give it a try. What you got to lose?