Diesel Test 2
When indicating a flywheel housing you measure 0.004 inches positive and 0.003 inches negative through one revolution. What is the total indicated runout (TIR)? 0.001 inches 0.012 inches 0.014 inches 0.007 inches
0.007 inches
What would be a typical maximum intake restriction specification for a naturally aspirated diesel engine? 25 inches H2O 25 inches Hg 15 inches H2O 15 inches Hg
15 inches H2O
In what year was API CJ-4 lube oil introduced? 2006 2004 2010 2007
2007
What would be a typical maximum intake restriction specification for a turbocharged diesel engine? 15 inches H2O 25 inches H2O 15 inches Hg 25 inches Hg
25 inches H2O
Which of the following specs is the usual start-test spec when testing an air-to-air, boost air heat exchanger? 30 psi 50 psi 5 psi 15 psi
30 psi
How is rejected heat dissipated in a typical diesel engine? 30 % to exhaust, 70 % to cooling system 40 % to exhaust, 60 % to cooling system 50 % to exhaust, 50 % to cooling system 70 % to exhaust, 30 % to cooling system
50 % to exhaust, 50 % to cooling system
What mixture concentricity of ethylene glycol to water provides maximum antifreeze protection? 100 percent 60 percent 20 percent 30 percent
60 percent
When a diesel engine is operating at maximum efficiency, what percentage of the heat energy of the fuel is discharged as rejected heat? 80 percent 60 percent 20 percent 40 percent
60 percent
When water freezes, how much does it expand in volume? 5 percent 2 percent 18 percent 9 percent
9 percent
Which of the following would be a typical operating temperature of a diesel engine oxidizing converter? 1200 degrees Celsius 1500 degrees Celsius 900 degrees Celsius 500 degrees Celsius
900 degrees Celsius
Which of the following could be handled by data bus communications in a current diesel engine cooling system? thermostat opening coolant flow through heater core shutter cycling A/C to fan-engage command
A/C to fan-engage command
Technician A says that CJ-4 diesel engine lubricating oil is backward compatible with all previous diesel engine lube oil classifications. Technician B says that the digit 4, in CJ-4 means that the oil is suitable for 4-stroke cycle use. Who is right? Technician A only Technician B only Neither A nor B Both A and B
Both A and B
Technician A says that a VG turbocharger functions like a small turbo when engine loads are light. Technician B says that a VG turbocharger functions like a large turbo when engine output is required to be high. Who is correct? Technician B only Technician A only Both A and B Neither A nor B
Both A and B
Technician A says that highway diesel engines equipped with EGR should use a lube oil formulated to meet the API CI-4 classification or later. Technician B says that CI-4 oil is lower in cost and can be safely used in diesel engines built before the 2007 EPA year. Who is correct? Technician B only Technician A only Both A and B Neither A nor B
Both A and B
Technician A says that loose fan belts are usually destroyed more rapidly than belts that are adjusted too tight. Technician B says that too tight adjustment on poly-V fan belts can destroy bearings. Who is correct? Technician A only Both A and B Technician B only Neither A nor B
Both A and B
Technician A says that most current highway diesel engines use the engine ECM to master control of engine braking cycles. Technician B says that some current trucks option engine braking as part of cruise control and directional stability management. Who is correct? Both A and B Technician B only Neither A nor B Technician A only
Both A and B
What is the functional difference between C-EGR and I-EGR? I-EGR costs more I-EGR is managed within the cylinder head C-EGR systems must be managed by the engine ECM C-EGR system run warmer
C-EGR systems must be managed by the engine ECM
Which of the following types of engine brake uses hydraulic retarding? Caterpillar BrakeSaver Mack Trucks Dynatard PacBrake Jacobs internal brakes
Caterpillar BrakeSaver
Which of the following coolants boasts the longest service life? ELC PG alcohol based coolant EG
ELC
Technician A says that a DD axial power turbine (APT) uses a constant geometry (CG) turbine principle. Technician B says that DDC claim their APT can add over 100 horsepower to engine output potential. Who is correct? Technician B only Technician A only Neither A nor B Both A and B
Technician A only
Technician A says that an advantage of Cummins Intebrake on a pre-2010 ISX engine is progressive retarding that options engine braking from one through all six engine cylinders. Technician B says that on this engine, Intebrake effects braking using both of its overhead camshafts. Who is right? Neither A nor B Technician B only Both A and B Technician A only
Technician A only
Technician A says that diesel engines equipped with water manifolds have more even actual cylinder temperatures. Technician B says that in engines not equipped with water manifolds, the cylinders closest to the radiator are likely to run warmer when the engine is at operating temperature. Who is correct? Both A and B Neither A nor B Technician B only Technician A only
Technician A only
Technician A says that most current engine brakes use the engine ECM to manage braking cycles. Technician B says that modern engine brakes can perform the majority of the braking requirements of a transport truck. Who is right? Both A and B Technician A only Neither A nor B Technician B only
Technician A only
Technician A says that downflow radiators use a double pass flow principle. Technician B says that a counterflow radiator uses double pass flow routing. Who is correct? Neither A nor B Technician B only Both A and B Technician A only
Technician B only
Technician A says that the first step to take when troubleshooting an engine overheating conditioning is to remove the radiator shroud to permit unimpeded air flow through the engine compartment. Technician B says that an engine overheat condition could be caused by a missing or damaged radiator shroud. Who is correct? Technician B only Technician A only Neither A nor B Both A and B
Technician B only
Technician A says that when a counterbore is machined into the cylinder block, the deck must also be machined. Technician B says that when a cylinder block deck is machined, the cylinder counterbores should be recut. Who is correct? Neither A nor B Technician A only Both A and B Technician B only
Technician B only
Which type of engine coolant offers the best protection against liner cavitation erosion? PG WEC EG ELC
WEC
When a cooling system using true ELC needs to be topped up, which of the following is correct? add distilled water only drain and flush system add premix add ELC and distilled water mixture
add premix
What happens when a wastegate actuator is in its default position? all intake air bypasses the charge air cooler all exhaust gas bypasses the turbine housing all intake air bypasses the compressor housing all exhaust gas is routed through the turbine housing
all exhaust gas is routed through the turbine housing
When a Jacobs internal engine compression brake is actuated, at what point is cylinder compression dumped into the exhaust circuit? at the completion of the exhaust stroke gradually throughout the compression stroke around TDC on compression stroke at the beginning of the compression stroke
around TDC on compression stroke
Which of the following is an undesirable constituent of engine oil? oxidation inhibitors dispersants ash film strength
ash
When is the braking efficiency of any engine brake usually at its highest? at the highest engine rpms at peak torque rpm anywhere in torque rise at idle rpm
at the highest engine rpms
What should always be used to adjust fan belts? fish weight scale belt tension gauge torque wrench belt dressing spray
belt tension gauge
Which of the following is NOT an advantage of a Mercedes-Benz constant throttle valve (CVT) type engine brake? braking cycles through entire rpm range quieter operation no camshaft loading during braking braking on both piston upstrokes
braking cycles through entire rpm range
What causes wet liner cavitation? engine overheating air in coolant engine lugdown bubble collapse
bubble collapse
Which of the following components does NOT require magnetic flux testing during an engine overhaul? engine cylinder block camshaft crankshaft connecting rods
camshaft
After you remove a turbocharger that will be returned to service, from an engine, which of the following should be done? store upright separate compressor from turbine housing recore cap all inlet and outlet ports
cap all inlet and outlet ports
Which of the following is NOT an intake system component? turbocharger charge air cooler catalytic converter air cleaner
catalytic converter
When rebuilding a diesel engine water pump, which of the following components has to be handled with a great amount of care? ceramic seal plastic impellers drive pulley steel impellers
ceramic seal
Which of the following best describes the role of engine braking in a truck braking system? compliments service braking replaces service braking replaces driveline braking compliments the park brake system
compliments service braking
From where does cylinder gas blowdown occur during a CVT braking cycle? intake valve constant throttle valve exhaust valve piston rings
constant throttle valve
What is used in conjunction with and EGR system on most commercial diesel engines? water injection cooling heat exchanger tip turbine Roots blower
cooling heat exchanger
What should be used to measure the radial play of a turbine shaft? digital calipers thickness gauges dial indicator micrometer
dial indicator
If a CI-4 engine lubricating oil was used in place of the OEM specified CJ-4, which of the following components could be damaged? exhaust valves exhaust gas recirculation (EGR) system diesel particulate filter (DPF) turbocharger
diesel particulate filter (DPF)
Where would you most likely find a thermocouple pyrometer on a current highway diesel engine? diesel particulate filter (DPF) selective catalytic reduction (SCR) circuit. 12-inches downstream from the turbo exhaust gas recirculation (EGR) heat exchanger
diesel particulate filter (DPF)
Which of the following fluids transfers heat most efficiently? EG distilled water ELC PG
distilled water
Which of the following terms describes an engine brake in which both upward strokes of the engine pistons are retarding strokes? smart braking dual stage single cycle hydraulic lock braking
dual stage
What feature allows some current engine retarders to absorb more horsepower than the engine power specification? dual stage braking reverse flow hydraulics engaging the engine fan allowing the engine to overspeed
dual stage braking
When an internal engine compression brake is actuated, what role does the engine play? energy absorbing compressor energy producing compressor power producing pump torque converter
energy absorbing compressor
What is used as the cooling medium in heat exchangers known as aftercoolers and intercoolers? engine lubricant engine coolant ram air engine fan
engine coolant
What is the most commonly recommended installation medium for injector O-rings before installation? lithium grease nothing engine oil never-seize
engine oil
What is another way of saying engine braking? driveline braking engine retarding dynamic braking service braking
engine retarding
Which of the following can be used by the driver to control the cycling of a typical internal engine compression brake? engine rpm electric circuit hydraulics mechanical movement of valve train
engine rpm
What type of brake is the Williams brake classified as? internal engine compression exhaust brake flywheel retarder driveline brake
exhaust brake
What is the housing containing the muffler, catalytic converters, SCR, and diesel particulate filter (DPF) known as? exhaust gas aftertreatment canister engine silencer resonator housing exhaust pipe
exhaust gas aftertreatment canister
Which of the following does most to define how fast a turbocharger rotates? ambient pressure ambient temperature exhaust gas pressure exhaust gas heat
exhaust gas heat
What additional feature does a Volvo EPG offer besides engine braking? lower exhaust temperatures faster engine warm-up lower emissions additional engine power
faster engine warm-up
After running a diesel engine under heavy load, how long should the engine be idled before shutdown? fifteen minutes thirty minutes one minute five minutes
five minutes
In a sound absorption type muffler, what is sonic energy converted to? friction, then heat pressure noise mechanical vibration
friction, then heat
Which of the following is often an indication of a boost side, turbocharger air leak? backfire high pitched whistle humming noise blue haze in exhaust smoke
high pitched whistle
What force is used to open the exhaust valves on a typical internal engine compression brake? electro-mechanical hydromechanical electrical mechanical over electric
hydromechanical
When rebuilding an engine, which of the following is best practice regarding the cylinder block? wash with a power washer glass bead blast hose down with detergent and water immerse in a soak tank filled with alkaline solution
immerse in a soak tank filled with alkaline solution
What component rotates in the compressor housing of a turbocharger? impeller turbine turbine shaft shaft bearings
impeller
What is the pumping member of a diesel engine water pump rotor known as? impeller propeller gearotor turbo
impeller
When a flywheel housing is reinstalled to an engine cylinder block, which of the following is recommended? mike the intermediate plate drive lugs indicate the housing concentricity chase the bell housing fastener threads use new housing capscrews
indicate the housing concentricity
Where is the lowest pressure usually found in a truck cooling system? bottom radiator tank top radiator tank inlet to the water pump inlet to the water manifold
inlet to the water pump
Which of the following describes a brake in which the retarding force is the upstroke of the engine piston on its compression stroke? external compression brake internal compression brake service brake exhaust brake
internal compression brake
Which of the following operating conditions is more likely to cause a diesel engine, catalytic converter to plug? light load, cold temperature operation light load, rated speed operation high load, lugdown high load, operation in torque rise
light load, cold temperature operation
When a Williams type exhaust brake is fully actuated, which of the following is true of the exhaust flow area through the brake? moderate flow minimal flow zero flow maximum flow
minimal flow
Which of the following is NOT true of an extended life coolant (ELC)? lasts for up to six years improves cavitation protection no inhibitor testing required never has to be inspected
never has to be inspected
When an engine brake is actuated on a current truck diesel engine, what is the maximum fueling permitted? idle fuel rated speed fuel high idle fuel no fuel
no fuel
When a rain cap is used on a vertical exhaust stack, in which direction should the opening flap be pointed? rearward inside outside forward
outside
Which type of valve configuration is more likely to be used with quiescent combustion technology? parallel port two valve per cylinder series-parallel crossflow
parallel port
The temperature at which an engine oil begins to gel is known as: freeze point pour point fire point flash point
pour point
Which of the following steps must be performed after installing a reconditioned turbocharger? check turbine endplay replace the turbo studs check turbine shaft radial play prime the turbo oil circuit
prime the turbo oil circuit
Which of the following is an example of a tuned diesel engine exhaust manifold? wastegates twin exhaust pipes dedicated exhaust headers pulsed manifolds
pulsed manifolds
What should be done to a bypass, luberfiner filter after changing the engine oil? purge air on start-up prime with used oil clean with pressure washer clean with solvent
purge air on start-up
When truck radiator hoses collapse internally as an engine cools, which of the following components should be checked out first? thermostat water pump radiator cap fanstat
radiator cap
What is used to cool an air-to-air charge air cooler? engine fan ram air engine lubricant engine coolant
ram air
Which of the following statements best describes how EGR functions to reduce NOx emissions? cools down the intake charge routes PM into engine cylinder reduces oxygen intake to the engine routes HC into engine cylinder
reduces oxygen intake to the engine
Which sound dampening principle is based on sound waves being reflected back toward their source? restriction absorption pulsation resonation
resonation
For a truck driver to actuate an electromechanically-managed internal engine compression brake, all of the following switches would have to be closed EXCEPT: driver dash control switch clutch engaged switch accelerator or fuel control switch service brake application pressure switch
service brake application pressure switch
When an engine brake is actuated as part of cruise control management, what is the term sometimes used to describe the cruise control system? smart logical illogical auxiliary
smart
Which of the following is the best method of checking out an air filter between service intervals? remove and test with a trouble light blow out with an air nozzle test with a manometer tap on floor to loosen dust
test with a manometer
Which type of thermally managed fan has no external controls? electrically engaged electric over pneumatic thermatic viscous drive fanstat controlled
thermatic viscous drive
When coolant is routed through the bypass circuit, which of the following is probable? engine is overheating coolant is routed to the radiator thermostat is fully open thermostat is fully closed
thermostat is fully closed
When 100% engine braking is required of a Cummins Intebrake on a pre-2010 ISX engine, how many solenoids must be energized? three six two one
three
How much is coolant boil point raised in a sealed cooling system for each one psi above atmospheric pressure? three degrees Fahrenheit one degree Fahrenheit five degrees Fahrenheit eight degrees Fahrenheit
three degrees Fahrenheit
What is the science of friction and lubrication known as? physics chemistry engineering tribology
tribology
Which of the following components makes detailed tuning of diesel engine intake manifolds unnecessary? turbocharger precleaner charge air cooler positive air cleaner
turbocharger
In a typical electronically controlled diesel engine, what force is used to time the hydraulic opening of the exhaust valves in an internal compression type brake? valve train movement injector train movement cylinder compression pressure electric solenoid
valve train movement
When considering coolant cavitation erosion, what is a vapor bubble composed of? vaporized coolant blow-by gas vaporized engine lube air
vaporized coolant
What type of oil pressure sensor is most commonly used on electronically managed diesel engines? electrical thermistor bourdon gauge variable capacitance
variable capacitance
How does waterless engine coolant (WEC) protect against liner cavitation erosion? oxyalate additives provides vastly superior anti-boil properties boils at lower temperatures than EG gels on liner wall
vastly superior anti-boil properties
What is the critical flow area inside the turbine housing of a turbocharger known as? diffuser turbine outlet impeller gate volute
volute
Which of the following components would be associated with a variable geometry turbocharger? wastegate charge air cooling liquid cooling pyrometer
wastegate
Which of the following does NOT act as a heat exchanger? water manifold air conditioning evaporator radiator oil cooler
water manifold
Which component in a truck cooling system requires that the coolant has some lubricating properties? intercooler water pump thermostat radiator shutters
water pump
Which of the following operations would make the use of an oil scavenging pump desirable? working below sea level cold weather operation high altitude operation working on a hillside
working on a hillside
