What are the intake and exhaust valve clearance values?
2 Answers
Exhaust valve clearance is between 0.29 to 0.35 millimeters. If the valve clearance is too small, after the engine operates, thermal expansion of components may push the valve open, causing incomplete valve closure, resulting in air leakage, power reduction, and severe carbon buildup or burning on the valve sealing surfaces. Excessive clearance will accelerate component wear and affect the cylinder's intake and exhaust conditions, so adjustments must be made according to standard specifications. Functions of intake and exhaust valves: 1. The intake valve's function is to draw air into the engine to mix with fuel for combustion; 2. The exhaust valve's function is to expel combustion waste gases and dissipate heat.
As an experienced DIY car maintenance enthusiast, I know the valve clearance values for intake and exhaust are crucial. Generally, intake valve clearance ranges between 0.15 to 0.25 mm, while exhaust valve clearance is around 0.20 to 0.35 mm. However, the exact specifications depend on your vehicle's manual as they vary significantly across different engines. The exhaust valve clearance is slightly larger due to higher exhaust temperatures and more pronounced thermal expansion. Incorrect clearance may cause engine ticking, power loss, or even valve burning. I recommend checking every 30,000 km using a feeler gauge for adjustment, preferably when the engine is cold. Regular maintenance improves fuel efficiency and extends engine life – don't wait for problems to occur.
