最近我们大修了一辆4缸奥迪轿车,大修时更换了气门与气门导管。大修完磨合运行4小时后发现该车气门响,怀疑是气门挺杆(液压挺杆)的问题,于是换了一组新的气门挺杆。旧的挺杆经检查,压力正常,无明显问题。新气门挺杆装上后,气门脚响声依旧。又怀疑是气门挺杆与座孔之间的间隙过大,导致机油泄漏过多,油压低,气门挺杆起不到自动调节作用。把缸盖拆开后,测量气门挺杆与缸盖上痤孔之间的配合间隙是0.07mm(标准0.02～0.03mm)。为此,我们换上了一个新缸盖,但故障并没有排除,气门脚还是照响不误。于是又考虑到 Recently, we overhaul a 4-cylinder Audi sedan, overhauling the replacement of the valve and valve guide. Overhaul after running 4 hours running and found the car valve rang, suspected to be tappet (hydraulic tappet) problem, so for a new set of valve tappet. Old tappet after inspection, normal pressure, no obvious problem. New valve lifter fitted, the valve foot still sound. Also suspect is the gap between the valve tappet and the seat hole is too large, resulting in excessive oil leakage, low oil pressure, valve tappet fail to automatically adjust the role. After the cylinder head is disassembled, the clearance between the acupuncture hole on the measuring lifter and the cylinder head is 0.07mm (standard 0.02 ~ 0.03mm). To this end, we put on a new cylinder head, but the fault did not rule out the valve foot still sound correct. So take it into account again