Valves control the flow of fuel vapor into the combustion chamber and the flow of exhaust gases leaving the engine. Faulty or dirty valves may stick and can develop pits, cracks or grooves that cause the engine to lose power and fuel efficiency. When you remove the valves from the engine, inspect them carefully. Then, if the valves are not badly worn and the parts are not damaged, you can tune up the valves and seats so that the valves seal effectively.

Valves control the flow of fuel vapor into the combustion chamber and the flow of exhaust gases leaving the engine. Faulty or dirty valves may stick and can develop pits, cracks or grooves that cause the engine to lose power and fuel efficiency. When you remove the valves from the engine, inspect them carefully. Then, if the valves are not badly worn and the parts are not damaged, you can tune up the valves and seats so that the valves seal effectively.