What Causes Engine Piston-to-Valve Interference?
2 Answers
Causes of engine piston-to-valve interference: 1. Hard objects falling into the combustion chamber; 2. Broken intake/exhaust valve springs causing valves to drop into cylinders; 3. Replacement pistons with incorrect geometric dimensions during overhaul; 4. Excessive thickness of replacement connecting rod bearings or gaskets during overhaul; 5. Damage to cylinder block surface caused by frequent cylinder head gasket failures. Repair methods for piston-to-valve interference: 1. For minor cases, only piston and valve replacement is needed; 2. For severe cases causing crankshaft journal bending, replacement of crankshaft, connecting rods, and bearing shells is required; 3. For extreme cases where cylinder walls are penetrated, replacement of cylinder liners, intake/exhaust valves, valve seats, valve stem seals, valve guides, valve oil seals, and camshaft is necessary.
I'm a seasoned veteran in the auto repair industry. The most common cause of engine valve collision is timing chain or belt failure. A worn-out, broken chain or insufficient tension causes the valves and pistons to move out of sync, leading to mutual collision damage. Additionally, improper valve clearance adjustment is another culprit – insufficient lubrication increases friction between engine components, making them prone to seizing. I often see cases where incorrect ignition timing or severe carbon buildup causes uneven heat conduction, leading to engine overheating and valve collision. Poor routine maintenance, such as neglecting regular oil changes or cooling system cleaning, significantly increases the risk. I recommend car owners check timing components and fluid levels every six months – spending a little on prevention can avoid major repairs.
