单项选择题
In a diesel engine, a cylinder liner should be replaced if it is （） Ⅰ.Scuffed Ⅱ.Scored
A.Ⅰ only is correct B.Ⅱ only is correct C.both Ⅰ and Ⅱ are correct D.neither Ⅰ or Ⅱ are correct
Under normal conditions, the main source of crankcase o...
单项选择题Under normal conditions, the main source of crankcase oil contamination is attributed to （）
A.metal particles loosened by wear B.air when air cleaners are not used C.condensation of water vapors D.breakdown of the lubricating oil by dilution
Valve cages are used on some large diesel engines to （）...
单项选择题Valve cages are used on some large diesel engines to （）
A.reduce wear on the valve stem B.permit the use of alloy valve seat materials C.reduce heat transfer from the valve seat D.facilitate valve removal for servicing
If the jacket water temperature rises rapidly above nor...
单项选择题If the jacket water temperature rises rapidly above normal in a diesel engine, you should FIRST （）
A.place standby cooler in operation B.reduce engine load C.check thermostatic valve D.clean sea water strainer
