Internal Engine Leakage Inspection
One method is to operate the engine for a short period to churn the oil and the remove the engine dipstick, and inspect for water globules on the stick. Depending on the results, it may be necessary to remove the engine oil pan drain plug and drain a small amount of engine oil. If coolant is present in the pan, it will drain first because it is heavier than oil.
With radiator pressure tester tool installed on radiator, do not allow pressure to exceed 145 kpa (21 psi). Pressure will build up quickly if a combustion leak is present. To release pressure, rock tester from side to side. When removing tester, do not turn tester more than 1/2 turn if system is under pressure.
Operate the engine without the pressure cap on the engine pressurized coolant bottle until the thermostat opens. Attach a Pressure Tester to the filler neck. If pressure builds up quickly, it may indicate a combustion leak exists. This is usually the result of a cylinder head gasket leak or a crack in the engine. Repair as necessary.
If there is not an immediate pressure increase, pump the Pressure Tester until indicated pressure is within the system range of 110 kPa (16 psi). Fluctuation of the gauge pointer indicates compression or combustion leakage into the engine cooling system.
Because the vehicle is equipped with a catalytic converter, do not short out cylinders to isolate the compression leak.
If the needle on the dial of the pressure tester does not fluctuate, increase the engine RPM's a few times to check for an abnormal amount of coolant or steam. This would be emitted from the exhaust pipe. Coolant or steam from the exhaust pipe may indicate a faulty cylinder head gasket, cracked engine cylinder head or cylinder block.