Excessive Oil Consumption
- Intake or exhaust valve "O" ring seal damaged or has excessive looseness.
- Worn valve stems or guides.
- Plugged oil drain back holes.
- Improper PCV valve operation.
- Engine oil level too high.
- Engine oil too thin.
- Valve stem oil deflectors missing or damaged.
- Piston rings improperly installed or incorrect size.
- Piston rings out-of-round, broken or scored.
- Piston ring gaps not staggered.
- Piston ring tension insufficient due to engine overheating.
- Piston ring grooves or oil return slots clogged.
- Piston rings sticking in ring grooves.
- Ring grooves worn excessively.
- Compression rings installed upside down.
- Excessively worn or scored cylinder walls.
- Mismatch of oil ring expander and rail.
- Intake gasket dowels too long.
- Excessive main or connecting rod bearing clearance.