Oil Consumption Testing (TT 17-11-03)

NORMAL OIL CONSUMPTION

• Mileage below 50,000: Normal oil consumption is one quart for each 1,000 miles driven.
• Mileage above 50,000: Normal oil consumption is one quart for each 750 miles driven.

TEST TO DETERMINE ENGINE OIL CONSUMPTION

1. Operate engine to normal operating temperature.
2. Fill engine oil precisely to FULL mark on dip stick gauge.
3. Use paint pen to mark the engine oil drain plug to prevent tampering.
4. Check engine oil level after 1.000 miles driven. Refer to normal engine oil consumption listed above.

POSSIBLE CAUSES FOR EXCESSIVE ENGINE OIL CONSUMPTION

• PCV OR CCV SYSTEM: Check the crankcase ventilation system for proper operation. Oil may accumulate in the throttle body or intake manifold. Rocker arm lubrication oil flow returns to oil pan through drain back holes in top of cylinder head. Plugged or restricted oil drain back holes may contribute to excessive oil in crankcase ventilation system.
• SPARK PLUGS: Examine all spark plugs to identify the affected cylinder(s). Spark plug on the affected cylinder(s) will usually be fouled or wet with engine oil.
• VALVE GUIDES AND VALVE STEM SEALS: Inspect valve guides on the affected cylinder(s). Replace valve stem seals on the affected cylinder(s).
• PISTON RINGS: Check piston rings on the affected cylinder(s). Piston rings may be too tight, worn, or broken or there may be carbon build up in the oil control ring.
• CYLINDER WALL: Examine the cylinder wall on the affected cylinder(s). Cylinder wall may be severely scuffed.

Be aware that a procedure for oil consumption testing is available in the Repair Manual under Non-DTC Based Diagnostics as shown below.