一辆东风康明斯发动机6吨平头货车,已行驶十几万公里,由于发动机进气管有异响,来我厂检修。驾驶员说:异响故障已有4个月左右,原先车子很有劲,现在差多了。检查气门间隙,其隙基本正常。初步诊断为进气门关闭不严。拆下气缸盖检查气门,发现6个进气门均有严重积炭,第5、6两缸进气门密封带由于积炭过多 A Dongfeng Cummins engine 6 tons flat truck, has traveled hundreds of thousands of kilometers, due to the engine intake pipe abnormal noise, to our factory overhaul. The driver said: abnormal noise fault has been about 4 months, the original car is very strong, now much worse. Check the valve clearance, the gap is normal. Initial diagnosis of the intake valve is not strict. Remove the cylinder head check the valve and found that six intake valves have serious coke, the first five or six cylinder intake valve sealing tape due to excessive coke