In a non-interference engine, a timing belt failure is unlikely to cause which damage?

• A. Piston damage
• B. Crankshaft damage
• C. Valve damage
• D. Cylinder wall damage

Answer: (C)

When the timing belt fails, the risk of piston-to-valve contact depends on whether the engine is interference or non-interference. In a non-interference design, there is enough clearance between the pistons and valves that, even if the cam timing is lost, the piston and valve do not collide. That’s why valve damage from a belt break is unlikely. The engine may run poorly or stall and can still suffer other mechanical stresses (like abnormal combustion or stress on pistons, cylinders, or the crank) due to timing loss, but the valves themselves are protected from contact.