poor cooling of cylinder walls
improper cooling of the piston
insufficient piston lubrication
all of the above
第1题：
Low compression in a diesel engine could be caused by
A.worn or broken cylinder liner sealing rings
B.high cooling water temperature
C.worn or broken piston rings
D.low fuel oil pressure
第2题：
high combustion temperature
high compression pressure
cracked cylinder liner
fuel with a high vanadium content
第3题：
Combustion knock occurring in a diesel engine can be caused by _____.
A.low coolant temperature
B.insufficient fuel
C.high ambient temperature
D.carbon buildup on the injector tips
第4题：
high compression pressure
low intake air temperature
low exhaust pressure
high scavenge air temperature
第5题：
starting the engine while hot
knurling the piston skirt
operating the engine overheated
scuff resistant piston rings
第6题：
Persistent knocking in one cylinder of an eight cylinder diesel engine would MOST likely be caused by______.
A.using fuel oil with low cetane number
B.a badly worn piston pin
C.a loose flywheel key
D.a loose bed plate bolt
第7题：
a leaking fuel injector nozzle
a clogged air filter
excessively early fuel injection
malfunctioning valves
第8题：
A crack in a cylinder liner can be caused by
A.worn piston rings
B.installation of undersized sealing rings
C.operating the engine at low loads
D.restricted cooling water passages
第9题：
oil spray
oil bath
oil control rings
drilled passage through the camshaft
第10题：
excessive lube oil consumption
lower than normal lube oil temperature
higher than normal exhaust back pressure
excessive crankshaft end play