What to Do About Engine Air Leak?

[GriffinRose]

Engine hissing indicates an air leak, which can cause rapid power loss. There are several reasons for valve leakage: 1. Wear or erosion on the contact surfaces between valves and valve seats, leading to spots, pits, or carbon buildup. 2. Excessive clearance between valve stems and guides causing wobbling, preventing proper valve closure, or bent valve stems resulting in misalignment and leakage - often producing a "whooshing" or "hissing" sound. 3. Weakened, broken, or lost elasticity in valve springs, compromising the seal between valves and seats.