In interference engine designs, replacing a timing belt in regular intervals (manufacturers recommend intervals ranging from 60,000 to 104,000 miles (97,000 to 167,000 km)) or repairing chain issues as soon as they are discovered is essential, as incorrect timing may result in the pistons and valves colliding and causing extensive internal engine damage. The piston will likely bend the valves, or, if a piece of valve or piston is broken off within the cylinder, the broken piece may cause severe damage within the cylinder, possibly affecting the connecting rods. If a timing belt or chain breaks in an interference engine, mechanics check for bent valves by performing a leak-down test of each cylinder or by checking the valve gaps. A very large valve gap points to a bent valve. Repair options depend on the extent of the damage. If the pistons and cylinders are damaged, the engine must be rebuilt or replaced. If the valves are bent but there is no other damage, replacing the bent valves, rebuilding the cylinder head, and replacing the timing belt/chain components may be sufficient.2
Explanation of the results of timing belt failure in an interference engine. aa1car.com. Retrieved September 16, 2024 http://www.aa1car.com/library/timing_belts_interference_engines.htm ↩
"Interference versus Non-Interference engine: animation, repair options". testingautos.com. TestingAutos. Retrieved 2020-01-09. https://www.testingautos.com/car_care/interference-engine.html ↩