Q: 2002 Saturn l100 2.2. Weak crank no start. Replaced plugs, starter, battery.

There are a number of things this could be. If the turning the motor over without spark plugs did not change the sound or strength of the ability of the motor to turn over, this could suggest a blow head gasket or some type of leak. A blown head gasket may cause a number of different symptoms. Coolant in the engine oil, an engine misfire or oil leaking from the engine could all be symptoms. Each of these symptoms could also have other causes and an actual blown head gasket may show none of the above symptoms. Symptoms will often vary considerably, depending on how the gasket fails. Head gaskets may fail in several different ways. With each failure type different symptoms may result. The symptoms each person sees depend on how and where the head gasket fails. Head gaskets may fail in several different ways. For example, a restricted radiator may cause an engine to overheat, very much the same as a head gasket failure. Often times, intake gaskets will fail causing coolant to leak into the oil.

A warped or cracked cylinder head will also produce the exact symptom of a blown head gasket. An external inspection is the only way to determine if the problem is head gasket related. This may mean a blown gasket, warped or cracked cylinder head or other problems in the area. For instance corrosion on the head gasket surface will cause leakage, though technically not a blown gasket. I would recommend having an expert from YourMechanic come to your location to properly diagnose the symptoms you describe.