Internal Leakage Inspection

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.

• Operate the engine without the pressure cap on the radiator until the thermostat opens. Attach a Pressure Tester to the filler neck. If pressure builds up quickly, it indicates that a combustion leak exists. This is usually the result of a cylinder head gasket leak or crack in the engine. Repair as necessary.
• If there is not an immediate pressure increase, pump the Pressure Tester until the indicated pressure is within system range. Fluctuation of the gauge pointer indicates compression or combustion leakage into the cooling system.
• If the needle on the dial of the pressure tester does not fluctuate, race the engine a few times to check for an abnormal amount of coolant or steam emitting from the exhaust pipe. Coolant or steam from the exhaust pipe may indicate a faulty cylinder head gasket, cracked engine cylinder block or cylinder head.
• A convenient check for exhaust gas leakage into the cooling system is provided by a commercially available Block Leak Check tool. Follow the manufacturer's instructions when using this product.