SENR9977 45 Testing and Adjusting Section Overfilling of the crankcase Wrong dipstick or guide tube Sustained operation at light loads Excessive consumption of engine oil can also result if engine oil with the wrong viscosity is used. Engine oil with a thin viscosity can be caused by fuel leakage into the crankcase or by increased engine temperature. i01945015 Increased Engine Oil Temperature - Inspect Look for a restriction in the oil passages of the oil cooler (if equipped). The oil temperature may be higher than normal when the engine is operating. In such a case, the oil cooler may have a restriction. A restriction in the oil cooler will not cause low oil pressure in the engine.