单项选择题
A.high oil pressure
B.excessive bearing end play
C.plugged oil control rings
D.engine overload
单项选择题 An increase in the fuel injection pump discharge pressure can be caused by a/an （）
单项选择题 An efficient seal between the cylinder block and cylinder heads on many diesel engines is obtained with（）
单项选择题 What is the function of the after-cooler installed in the diesel engine air intakes system?（）