USCGQ
Log in Start free
USCGQ
Toggle sidebar
Home
Engine
Motor Plants and Auxiliary Boilers
Start practicing

Engine · 1,433 questions

Motor Plants and Auxiliary Boilers - USCG Exam Questions

Diesel engine theory and operation, fuel and lubrication systems, starting and reversing, and auxiliary boilers.

Every question below is a real U.S. Coast Guard exam question with four choices. Answer one and the correct choice is revealed instantly, with the USCG reference and illustration where the question uses one.

Random question Build a timed exam

All Motor Plants and Auxiliary Boilers questions

Questions 401–500 of 1,433 · page 5 of 15

  1. #622 Excessive side clearance between a piston ring and its groove will cause the ring to __________.
  2. #623 If the compression rings on a diesel engine piston become stuck in the ring groove, the cause may be due to __________.
  3. #624 After removing the bowl hood of the device shown in the illustration, excessive quantities of sludge are visible. Which of the following statements re... illustration
  4. #625 When tightening the lock ring "G" of the device shown in the illustration, two events are simultaneously accomplished. Which of the following statemen... illustration
  5. #626 Before any auxiliary diesel engine hydraulic starting system is opened for servicing or repair, you must __________.
  6. #627 The service life of a worn aluminum piston for an auxiliary diesel, for which no spares are readily available, can be extended by __________.
  7. #628 In an auxiliary diesel engine, one reason for knurling the piston skirt is to __________.
  8. #629 Decreasing the exhaust valve clearance of a diesel engine will cause the exhaust valve to open __________.
  9. #630 When inspecting the valve mechanism shown in the illustration, normal maintenance would include __________. Illustration MO-0074 illustration
  10. #631 Which of the following statements would apply when checking the valve clearance of the unit shown in the illustration? Illustration MO-0074 illustration
  11. #633 If sludge accumulates on the underside of a diesel engine piston, it will __________.
  12. #635 Before being shut down, a diesel engine should idle a few minutes in order to __________.
  13. #636 If the relief valve on a diesel engine cylinder lifts, the cause could be due to __________.
  14. #637 The diesel engine shown in the illustration can be fitted with a pyrometer at each exhaust elbow. If one of the cylinder pyrometers is reading signifi... illustration
  15. #638 White smoke issuing from the exhaust of an auxiliary diesel engine could mean __________.
  16. #640 When running a large, dual fuel, main propulsion diesel engine on heavy fuel, which of the following precautions should be observed when switching fro...
  17. #641 When restarting a heavy fuel diesel engine that has been stopped for some time, the engineer should __________.
  18. #642 One cause of diesel engine fuel ignition delay is __________.
  19. #643 When a fuel injection nozzle overheats, which of the problems listed can be expected?
  20. #644 High cylinder firing pressure, accompanied by low exhaust temperature, can result from __________.
  21. #645 In the common rail system, excessive pressure in the header may be caused by __________.
  22. #646 Surface irregularities, such as erosion and pitting on injection pump plungers, will __________.
  23. #648 While operating the fuel oil centrifuge shown in the illustration, the bowl fails to open for sludge ejection. The probable cause is that __________.... illustration
  24. #649 While operating the fuel oil centrifuge shown in the illustration, the fuel oil is being continuously ejected with the sludge and the seal water. The... illustration
  25. #651 For a diesel engine, approximately how long can an electric starter motor be operated continuously before damage may begin to occur due to overheating...
  26. #652 On a diesel engine with direct-cylinder admission air starting, a leaking air starting valve would be indicated by __________.
  27. #653 Which of the following conditions is most likely to occur if the electric starter motor pinion gear fails to disengage from the flywheel of a diesel e...
  28. #654 When starting air is admitted, a diesel engine turns over very slowly without firing. The cause may be __________.
  29. #655 When an additional load is applied to a diesel engine which is using an inadequately inflated air bladder clutch unit, you can expect __________.
  30. #656 Misalignment of the drive shaft and propeller shaft flanges can be detected by using a dial indicator or __________.
  31. #657 The gear drive, shown in the illustration, can have the backlash determined best by using a __________. Illustration MO-0091 illustration
  32. #659 What could cause the bypass valve in a full-flow lubrication system to open?
  33. #660 Lube oil in the fresh water cooling system of a diesel engine may result from a __________.
  34. #661 Which of the following effects will excessively cold lube oil have on the operation of a diesel engine?
  35. #662 A four-stroke cycle main propulsion diesel engine fails to start at normal cranking speed with normal fuel pressure and ambient temperature. The reaso...
  36. #663 Clogged or partially obstructed exhaust ports on a diesel engine can cause __________.
  37. #664 A diesel engine may be hard to start if the __________.
  38. #665 Combustion gas venting through the expansion tank can be caused by a __________.
  39. #666 Some diesel engines are fitted with a thermometer in the cooling water outlet from each cylinder. If the cooling water temperature from all cylinders...
  40. #667 A diesel engine cylinder head can crack as a result of __________.
  41. #669 Oil accumulating in the exhaust piping or manifold of a diesel engine can be caused by __________.
  42. #670 If there is a 'clicking' sound in the valve compartment of a diesel engine, the cause may be __________.
  43. #672 If an auxiliary diesel engine equipped with an electric starting system cranks very slowly after repeated attempts to start, the cause could be a/an _...
  44. #673 A diesel engine may fail to start when being cranked, due to __________.
  45. #674 High exhaust temperature and black smoke exhausting from an auxiliary diesel engine can be caused by __________.
  46. #675 Crank web deflection readings will give a positive indication of __________.
  47. #676 Prior to starting, the purpose of turning over a main propulsion diesel engine with the cylinder test cocks open, is to __________.
  48. #678 Excessive vibration from an auxiliary boiler could be caused by __________.
  49. #680 Which of the following conditions could cause the feed pump for an auxiliary boiler to lose suction?
  50. #681 If the operating speed of a diesel engine increases without an apparent change in the engine control settings, you may suspect a __________.
  51. #682 Governor hunting is caused by __________.
  52. #683 The hunting of a diesel engine may be caused by __________.
  53. #684 If the speeder spring of a main propulsion diesel engine governor breaks while operating at full load, the engine RPM will __________.
  54. #686 A propulsion engine, using the speed control circuit shown in the illustration, fails to function at speeds lower than the low end of the critical spe... illustration
  55. #689 Corrosion and grooving on the blading of an exhaust driven turbocharger is caused by certain components of residual fuel oils. These components are va...
  56. #690 Excessive mechanical and pulsating vibrations developed in a main propulsion diesel engine may be more likely to cause damage to an attached _________...
  57. #692 Before any work is to be carried out on a burner in an automatically fired auxiliary boiler, you should always __________.
  58. #693 The starter control valve in the hydraulic system shown in the illustration is malfunctioning. Before removing the valve, you must first __________. I... illustration
  59. #694 Which of the listed items should be secured before performing any maintenance on a solenoid operated air start valve?
  60. #695 When a nozzle tester is used to check the spray pattern of a diesel fuel injection nozzle, which of the following statements is true?
  61. #696 The principal hazard to personnel when using a diesel engine fuel nozzle tester is _______.
  62. #698 Which of the following precautions should be taken when cleaning the air filter on a diesel engine equipped with a turbocharger?
  63. #701 In the illustrated engine, the main camshaft controls the timing of which of the following components? Illustration MO-0003 illustration
  64. #702 The lower end of the piston rod, shown in the illustration, is fitted into the __________. Illustration MO-0003 illustration
  65. #706 In what figure of the illustration does the crosshead experience the greatest side thrust? Illustration MO-0025 illustration
  66. #713 Piston cooling fins are located __________.
  67. #716 During main engine performance testing it is noticed that the firing pressure of one cylinder is higher than the average, but cylinder compression pre...
  68. #717 During main engine performance testing it is noticed that one cylinder has firing and compression pressures lower than average. Which of the following...
  69. #719 Worn diesel engine intake valve guides can result in __________.
  70. #722 If a valve seat insert, similar to that shown in the illustration is cracked, this may be indicated by __________. Illustration MO-0043 illustration
  71. #723 Low compression pressure in a diesel engine can be caused by __________.
  72. #724 When one cylinder has a lower compression pressure and higher exhaust gas temperature than any of the other engine cylinders, which of the conditions...
  73. #727 The ring lands on a large, low-speed, main propulsion diesel engine piston may crack due to __________.
  74. #729 The most practical way of detecting an overload in one cylinder of an operating large, low-speed, main propulsion diesel engine is to __________.
  75. #730 One method of determining crankshaft misalignment is by __________.
  76. #731 A main propulsion diesel engine crankshaft bearing lacking sufficient 'crush', will __________.
  77. #737 When two cams of the same diameter, one with tangential flanks and the other with convex flanks are compared, the cam with tangential flanks will caus...
  78. #739 In diesel engines, hydraulic valve lifters are used to __________.
  79. #740 Before any auxiliary diesel engine hydraulic starting system is opened for servicing or repair, you must __________.
  80. #741 The service life of a worn aluminum piston for an auxiliary diesel, for which no spares are readily available, can be extended by __________.
  81. #742 In an auxiliary diesel engine, one reason for knurling the piston skirt is to __________.
  82. #743 If an auxiliary diesel engine equipped with an electric starting system cranks very slowly after repeated attempts to start, the cause could be a/an _...
  83. #744 On small diesel engines, a noticeable decrease in the time interval between the replacement of the lube filter cartridge indicates __________.
  84. #746 High exhaust temperature and black smoke exhausting from an auxiliary diesel engine can be caused by __________.
  85. #752 In a medium-speed marine propulsion engine equipped with direct admission air starting valves, the cylinders without air starting valves fire first be...
  86. #753 Which internal combustion engine starting system uses a vane type fluid motor?
  87. #755 Which of the following operating characteristics of the Bendix drive friction clutch is associated with a Bendix drive starter?
  88. #761 Intercoolers installed on starting air compressors, reduce the possibility of __________.
  89. #767 The purpose of an oil mist detector in a main propulsion diesel engine is to warn of __________.
  90. #769 One advantage of a vacuum feed sight glass indicator used on cylinder lubricators over the discharge side liquid filled type sight glass is __________...
  91. #770 Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are __________.
  92. #771 The rate of cylinder lubricating oil metered to each cylinder of a large, low-speed, main propulsion diesel engine is __________.
  93. #776 A 'Blotter test' is a test performed on the lube oil of a diesel engine which can determine ______.
  94. #778 If the analysis of used lube oil indicates a high content of iron particles, this could indicate __________.
  95. #779 A decrease in the flash point of diesel engine lube oil indicates the lube oil has become __________.
  96. #780 A bronze bearing liner with a lead-tin flashing has a milky-white color over most of its surface and some areas of exposed bronze. The white coloring...
  97. #781 A dirty lube oil strainer can result in __________.
  98. #782 Oil oxidation, as a result of excessively high lube oil temperature, is harmful to a diesel engine because __________.
  99. #783 Oil analysis for a crosshead type diesel engine indicates the TBN of the crankcase lubricating oil is increasing. This is most likely associated with...
  100. #785 When is fuel injected into a cylinder of diesel engines?

Motor Plants and Auxiliary Boilers questions: what to expect

Q How many Motor Plants and Auxiliary Boilers questions are in the Engine pool?

There are 1,433 Motor Plants and Auxiliary Boilers questions on this site, every one released by the U.S. Coast Guard or taken from the National Maritime Center's sample examinations, with its correct answer. The exam draws its Motor Plants and Auxiliary Boilers module from the same pool.

Q What score do I need to pass the Motor Plants and Auxiliary Boilers module?

Most USCG exam modules, including Motor Plants and Auxiliary Boilers, require 70 percent to pass. Rules of the Road modules require 90 percent.

Q Are these the real USCG Motor Plants and Auxiliary Boilers exam questions?

Yes. They are the published U.S. Coast Guard questions, matched to the National Maritime Center's 2026 sample examinations. Answer any question to see the correct choice, the USCG reference and the illustration where the question uses one.

Other Engine modules

About the Engine question pool

The Engine pool holds the current U.S. Coast Guard questions for engineering credentials, from QMED ratings through DDE and Assistant Engineer up to Chief. Answer any question to see the correct choice instantly.