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In an operating diesel engine, which of the following condition is an indication of a leaking air starting valve?（）
A . noise coming from that air starting valve
B . continuous operation of the starting air compressor
C . zero air pressure in the air starting system
D . overheated starting air pipe to the cylinder head
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A turbocharged, four-stroke/cycle diesel engine has a larger valve overlap than a naturally aspirated four-stroke/cycle diesel engine, in order to in crease the （）.
A . temperature of the exhaust gases
B . energy supplied to the turbocharger
C . air pressure to the intake manifold
D . purge of exhausted gases from the cylinder
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Engine coolant accumulating in the diesel engine lubricating oil can result from a （）
A . low oil pressure
B . high coolant pressure
C . leaking fuel injector
D . cracked cylinder head or liner
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A supercharged diesel engine when compared to a similar naturally aspirated diesel engine, will develop an increase in （）
A . ignition lag
B . engine horsepower
C . lube oil system pressure
D . specific fuel consumptio
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A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine（）
A . has little or no internal friction
B . has a lower effective compression ratio
C . operates with scavenge air under a positive pressure
D . operates without energy absorbing intake and exhaust stroke
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Before starting a diesel engine that has an engine driven lube oil pump, the engineer should （）.
A . open the bypass line
B . cut in the lube oil cooler
C . pressurize the lube oil system
D . top off the expansion tank
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An over-speed trip stops a diesel engine when the engine （）
A . runs out of fuel
B . has low lubricating oil pressure
C . exceeds a set maximum speed
D . has high cooling water temperature
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Leaking oil seals on a diesel engine turbocharger can cause（）
A . the engine to run after the fuel has been secured
B . the engine to over-speed
C . a fire
D . all of the above
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A diesel engine is supercharged in order to（）
A . lower the no-load RPMs
B . provide more air for combine with the fuel
C . increase the no-load RPMs
D . provide more fuel combine with the air
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Air scavenging of a diesel engine cylinder（）
A . blows out the exhaust gases
B . supplies oxygen for combustion
C . cools the valves and cylinder walls
D . all of the above
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If a crankcase explosion occurs in a diesel engine, you should stop the engine and（）
A . immediately open all crankcase relief ports
B . increase crankcase exhauster speed to draw cool air into the engine
C . allow the engine to cool naturally
D . increase crank case scavenge air to remove unburned gase
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Black smoke exhausting from a diesel engine indicates（）
A . proper fuel injection
B . water in the fuel
C . incomplete combustion
D . burning of lube oil
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Sudden unloading of a diesel engine can cause（）.
A . decreased fuel efficiency
B . increased exhaust temperature
C . black smoke
D . overspeed tri
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A diesel engine piston crown can crack from （）
A . excessive piston to liner clearance
B . excessive dirt beneath the piston crown that reduces heat transfer
C . faulty nozzle spray
D . all of the above
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The diesel engine is a type of （）.
A、A. turbine engine
B、B. gas turbine
C、C. steam engine
D、D. internal combustion engine
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Diesel oil may be used to cool （） of a diesel engine.
A . cylinders
B . exhaust valves
C . pistons
D . fuel valve
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A diesel engine burns （） a gasoline engine of the same capacity in the same period of time.
A . as much fuel as
B . less fuel than
C . less fuel as
D . more fuel tha
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If you suspect a diesel engine is misfiring due to air leakage into the fuel system, you should begin looking for the leak at the （）
A . fuel line connections to cylinder injection valves
B . gasket surfaces of the fuel oil filters
C . discharge fitting of the fuel injector pumps
D . suction side of the fuel oil tra
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A restricted air intake to a diesel engine may result in the engine （）.
A . failing to reach rated speed
B . knocking under maximum load
C . hunting or surging under light load
D . overspeeding and running away
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Before starting a diesel engine, you should always（）
A . check the pyrometer readings
B . check the crankcase oil level
C . check the fuel oil strainers
D . clean the fuel system
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A diesel engine is similar to a gasoline engine except that the former has no （）.
A . cross-head
B . cylinder
C . connecting rod
D . spark plug
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Some diesel engines are supercharged with a （）
A . slam charger
B . turbocharger
C . fuel atomizer
D . fuel injector
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"Scavenging" on a diesel engine means （）.
A . injecting fuel oil into a cylinder
B . removing exhaust gases from the cylinder
C . forcing air into the cylinders under pressure after the exhaust valve has dosed
D . a combination of all the above
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In a diesel engine, blow-by（）
A . increase exhaust back pressure
B . causes excessive crankcase pressure
C . can only be detected by a compression check
D . decreases fuel consumptio
