To test for a leaking head gasket
check for combustion gasses (CO2) in the cooling system. There is a tool known as a block tester that can do this or if you are really careful you can use an exhaust gas analyzer. If you suck up coolant it can damage the analyzer.
Of course, first you could use an "old fashioned" cooling system pressure tester. Pump it up to about 15psi and see where it leaks. If no external leaks are apparent then look for coolant in the cylinders, or crankcase.
check for combustion gasses (CO2) in the cooling system. There is a tool known as a block tester that can do this or if you are really careful you can use an exhaust gas analyzer. If you suck up coolant it can damage the analyzer.
Of course, first you could use an "old fashioned" cooling system pressure tester. Pump it up to about 15psi and see where it leaks. If no external leaks are apparent then look for coolant in the cylinders, or crankcase.