Four-Cylinder Engine Valve Clearance Adjustment Method?
2 Answers
Adjustment methods are as follows: 1. During assembly, use standard shims to measure the valve clearance value and place them on the valve pushrod to compensate for the gap. Replace the shims when they wear out. 2. Use hydraulic lifters, which automatically adjust the clearance. No adjustment is needed unless the hydraulic lifters are damaged. 3. For older gasoline engines, adjust the screw on the rocker arm to compensate for the gap when the valve is fully closed. 4. Valve adjustment sequence. Set the engine to the first cylinder working, adjust the intake and exhaust of the fourth cylinder, the intake of the third cylinder, and the exhaust of the second cylinder! Then set the engine to the fourth cylinder working, adjust the intake and exhaust of the first cylinder, the intake of the second cylinder, and the exhaust of the third cylinder.
Adjusting the valve clearance on a four-cylinder engine, I must say it's a meticulous job, but it's doable yourself. First, ensure the engine has cooled for at least six hours to get accurate clearance measurements. Remove the valve cover and prepare a feeler gauge, wrench, and gloves. Check the manual for the manufacturer's specifications, typically between 0.2 to 0.3 millimeters. Manually rotate the crankshaft to position each cylinder at top dead center on the compression stroke, then measure the gap between the valve stem and rocker arm. If it's too loose or tight, adjust the screw or replace the shim. Complete one valve before moving to the next to avoid confusion. Once done, reinstall the cover and start the engine—if there's no ticking sound, you've done it right. Regular adjustments can improve fuel efficiency and engine longevity, and I always notice smoother performance afterward.
