That is irrelevant. Cylinder head gaskets can leak coolant into the oil, into the combustion chamber, or outside the engine. They can also leak engine oil out of the engine or into the coolant, depending on whether the leak is at a passage with pressurized oil or an oil return passage to the crankcase. Coolant leaking into the combustion chamber, then going out the exhaust pipe is by far the most common failure. Coolant mixing with engine oil occurs in perhaps three to five percent of head gasket failures. The reason is there's only 15 pounds of pressure in the cooling system, about 40 pounds of pressure in the oiling system, but hundreds of pounds of pressure in the combustion chambers. That's where the weak spots will show up first, and the cooling system includes jackets around the cylinders. Being in such close proximity is why that is the most likely place for a leak to occur. The oil passages are usually pretty far removed from the cylinders and combustion chambers.
Wednesday, September 18th, 2013 AT 2:15 AM