Quiz #7: Q. 176-192

Question 1

One of the most common causes of reduction gear failure is gear wear caused by scoring as a result of __________.

Answer 1

an inadequate lube oil film

Question 2

In a diesel engine, a leaking exhaust valve can cause __________.

Answer 2

misfiring

Question 3

A dry-type exhaust silencer clogged with soot, will cause __________.

Answer 3

loss of engine power

Question 4

White smoke exhausting from a diesel engine can result from __________.

Answer 4

low cooling water temperature

Question 5

Black smoke exhausting from an operating diesel engine is an indication of poor combustion which may be caused by __________.

Answer 5

clogged air intake passages

Question 6

A diesel engine may be hard to start if the __________.

Answer 6

air intake is restricted

Question 7

QA main propulsion diesel engine is operating at 80% load and normal speed while the vessel is in calm seas. As the intensity of the seas increase, the engine speed governor maintains the same RPM, although the load indicator indicates an increase in load beyond its allowable limits. Which of the following actions should be taken?

Answer 7

Decrease the load limit setting.

Question 8

Maintaining the lowest possible scavenging air temperature at all times is not recommended due to the possibility of the __________.

Answer 8

formation of excessive quantities of condensate

Question 9

The power output of a turbocharged diesel engine will drop if the cooling water flow through the after cooler is interrupted because the __________.

Answer 9

air charge density decreases

Question 10

Which condition indicates the air side fouling of an after cooler on a turbocharged diesel engine?
A An increased air temperature differential between the cooler inlet and outlet.
B A decrease in the air pressure differential across the cooler.
C Excessive condensate forming in the air box.
D A decrease in the air temperature differential between the cooler inlet and outlet.

Answer 10

D A decrease in the air temperature differential between the cooler inlet and outlet.

Question 11

Which of the following problems can cause an above normal air temperature to develop in the intake manifold of a turbocharged and after cooled diesel engine?
A Faulty turbocharger turbine diffuser ring
B Faulty turbocharger compressor ring
C Insufficient cooling water flow to the after coolers
D Clogged air intake filters

Answer 11

C Insufficient cooling water flow to the after coolers

Question 12

An operating diesel engine that suddenly loses power, is due to a/an \_\_\_\_\_\_\_\_\_\_.
A	restricted turbocharger air intake
B	oil leak into the turbocharger
C	dribbling injector
D	low fuel viscosity

Answer 12

A restricted turbocharger air intake

Question 13

Corrosion and grooving on the blading of an exhaust driven turbocharger is caused by certain components of residual fuel oils. These components are vanadium, sodium, and __________.

Answer 13

sulfur

Question 14

A sudden power loss from a turbocharged and after cooled diesel engine is an indication of a/an \_\_\_\_\_\_\_\_\_\_.
A	turbocharger malfunction or failure
B	crankcase exhauster overload
C	overload on the intercooler
D	obstruction in the engine cylinders

Answer 14

A turbocharger malfunction or failure

Question 15

A thin film of oil on the lobes of a Roots-type blower indicates __________.

Answer 15

leaking rotor bearing oil seals

Question 16

Which of the following conditions is indicated by the presence of water in the scavenging air receiver?
A Leaking cylinder head gaskets
B Leaking aftercooler
C Excessively high scavenge air temperature
D Auxiliary blower failure

Answer 16

B Leaking aftercooler

Question 17

Excessive mechanical and pulsating vibrations developed in a main propulsion diesel engine may be more likely to cause damage to an attached __________.
A scavenged air pump because it is designed for steady state operation rather than pulsating gas load
B reciprocating scavenge pump because of its direct linkage to the crankshaft
C centrifugal cooling water pump because of the close tolerances required between the impeller rim and the volute
D gas driven turbocharger because it has a wide speed range, high operating temperatures and close tolerances.

Answer 17

D gas driven turbocharger because it has a wide speed range, high operating temperatures and close tolerances.