Q: The engine valve foot ring reason, how to deal?

A: The foot valve ring phenomenon is at low engine speeds, the upper part of the rhythmic clarity issued uniform "blah" sound, and the speed increases, the sound increases. In addition, the sound does not change with temperature _ and a single-cylinder off oil change.

⑴ reason

① foot valve clearance adjustment or improper adjustment screw lock nut loose.

② valve clearance adjustment screw or rocker wear.

③ cam wear excessive make tappet work produced beat.

④ valve push rod deformation.

⑵ diagnosis and treatment

① foot valve sound does not change with temperature change, but with the speed to change the level of sound frequencies. Sound clear when the valve cover and at idle.

② single cylinder test off the oil change will not affect the sound.

③ methods in order to avoid low-speed percussion ignition interference, can be quickly increase speed to close the throttle, the engine slow down while listening to the diagnosis.

④ Open the valve cover, hand pinch valve rocker arm vibration feeling relatively large, that is, the foot valve ring.

⑤ inserted into the gap with a feeler, when the sound disappeared for the foot valve ring.

⑥ hand to suppress the valve rocker arm moves up and down with it, if the sound diminished or disappeared, then the catheter or valve stem and rocker arm shaft gap is too large.

⑦identify the valve clearance is too large noise caused by the gap should be adjusted.

⑧ If the adjustment is still sound, check the cam wear (ie, measuring the top cam high) and putt without deformation. If worn or deformed should be replaced.