202 1 changan escape plus low-speed valve top ring

1. The sound is rhythmic and intermittent, located on the camshaft side; For engines with side valves, when the valve cover is removed, the sound is more obvious, and the tappet is a brittle "click, click" sound. When the engine is idling, the sound is obvious, generally weakening or disappearing above the medium speed.

2. The reason is that the deviation of cylindricity and roundness of tappet or guide hole is large or the fit is loose; Due to the wear and deformation of the spherical surface of the tappet or the big end of the cam (the cam loses its original axial inclination), the tappet does not rotate or does not rotate flexibly in the guide hole; Poor splash lubrication.

3. Check and judge that when the engine is idling, the camshaft side makes a firmer and crisper sound than the valve foot, and the "misfire" test does not disappear, so the engine speed can be increased to the medium speed test.