Oil Consumption Check List (With Engine Disassembled)

The following is a checklist to be used in assisting you to determine the reason for excessive oil consumption. This list is to be used when the engine is disassembled and pistons and rings are available for inspection.

  1. Incorrect Set for Job
    • Check for oversize cylinders and use of standard ring set. Try several rings in cylinder and if excessive gap, you have incorrect rings. Recheck by having cylinder miked.
  2. Rings Not Seated. Cylinders Show Areas Where Rings Did Not Contact
    • Cylinders distorted from heat or improper torquing.
    • Failure to deglaze cylinders properly. We recommend 220-300 grit stones.
  3. Ring Installed Wrong
    • Compression rings not installed according to instructions.
    • Rings not installed in proper groove.
    • Rings incorrect for groove width.
  4. Rings Spinning In The Groove
    • Usually side of compression rings will be highly polished.
    • Excessive blow-by.
    • Check for too much piston clearance.
    • Twisted or bent connecting rod.
    • Too much end play in the crankshaft.
    • More than normal vibration.
    • Cylinder walls highly polished or failed to deglaze cylinders.
  5. Rings Stuck in Groove (Common in late Engines)
    • Improper side clearance.
    • Water seepage into cylinders.
    • Check cylinder head and block surface.
    • Check head gaskets.
    • Check for cracks.
  6. Fractured or Broken Rings
    • Detonation, due to lugging, low-grade fuel, improper ignition setting.
    • Over heating.
    • Careless installation when installing rings and piston in the cylinders.
    • Failure to remove cylinder ridge.
  7. Side Wear on Rings-Top Groove Wear-Rings Badly Worn
    • Abrasive.
    • Gas wash.
    • Water seeping into cylinders.
    • Detonation.
    • Worn groove, allows ring to pound.
  8. Rings Scuffed
    • Lack of lubrication.
    • Low oil pressure.
    • Too slow idle during break-in.
    • Engine overheated, check cooling system.
    • Check for water or anti-freeze leaking into cylinders and destroying lubrication.
    • Failure to clean carbon from corners of groove.
    • Distorted cylinders.
    • Improper torquing of cylinder head.
  9. Cracked or Broken Ring Lands
    • Detonation.
    • Preignition.
    • Failure to remove all the ridge before removing pistons.
  10. Cracked Pistons
    • Common in late engines, extreme pressure due to carbon deposit in combustion chamber.
    • Detonation.
  11. Tight Piston Pins
    • Will affect the free action of the piston, resulting in rapid ring failure, piston and cylinder damage.
  12. Check Cylinder Taper
    • Check the cylinders at the top of the ring travel. Many high compression engines will have a sharp taper and out-of-roundness in the top half inch. V-8 engines generally wear more on the left side (sitting in the driver’s seat). Check all cylinders. Don’t take a chance.
  13. Check Piston Clearance
    • Mike cylinders and pistons. Feeler gauges bridge the wear spots and do not give a true picture. Failure to resize pistons will shorten the life of the rings due to the rocking action of the piston.
  14. Check Valve Assembly
    • The first step should be the removal of intake valves. Check under the head of the valves and the valve ports for an oil or carbon deposit. A deposit will indicate oil is being pulled into the combustion chamber due to a faulty booster pump, defective positive type breather system, or past the valve stems. A complete check must be made.
  15. Check Crankshaft
    • Mike the crankshaft rod journals for size, out-of-roundness and taper. Remember when bearing clearance is increased from .0015 to .004, you will have 6 times more oil thrown into the cylinders.
  16. Check Bearing Inserts
    • Check the inserts for fractures, wear and scoring.

Tough Guy Tech Tips: Piston Rings

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