API Which organization classifies all engine oil sold in North America? SAE Which organization grades engine oils by viscosity? thick film and boundary What two principles of fluid friction are used by an engine lubricating system? Blacker in color What is a common indicator that in engine oil has become contaminated with diesel fuel? Cloudy appearance What is an indication that engine oil has become contaminated with engine coolant? Ash Which of the following is an undesirable constituent of engine oil? Resistance to shear Which of the following properly defines viscosity? C1-4 What API oil classification is recommended for engines fueled by ultra low sulfur(ULS)fuel? Extreme cold weather operation In which of the following applications is the use of a synthetic engine oil especially recommended? 10 minutes after shutdown When should a diesel engine crankcase oil level be checked for the most accurate reading? External gear pump (only has one gear) What type of engine oil pump is most commonly used on truck diesel engines? 230ﾟF Which of the following values would be typical of engine oil at operating temperatures? Variable capacitance What type of oil pressure sensor is most commonly used on electronically managed diesel engines ? Main bearings When an engine oil analysis profile taken on a high mileage engine indicates higher than normal levels of copper which of the following components would more likely be at fault? Diesel particulate filter DPF If a C1-4 engine lubricating oil was used and place of the OEM specified CJ-4, which of the following components could be damaged? Both A and B are correct 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 that digit 4, in CJ-4 means that the oil is suitable for 4-stroke cycle engines. Who is correct? Both A and B are correct Technician a says that the highway diesel engines equipped with EGR should use a lube oil formulated to 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? Engine off, engine hot, syringe at mid sump level Which of the following methods would produce the most reliable results when drawing a sample of lube oil analysis? Both A and B are correct Technician A says that most engine OEMs recommend priming full flow oil filters following an oil change. Technician B says that failure to prime a full flow oil filter following engine lube service may damage the turbocharger when the engine is started. Who is correct? Low pressure intake circuit for leaks When an oil sample analysis indicates elevated levels of silicon, Which of the following should be inspected 1st? 40% to exhaust, 60% to cooling system How is rejected heat dissipated in a typical diesel engine? Conduction When the heat of combustion is transmitted through a diesel engine block, the principal is known as: Water Manifold Which of the following does NOT act as a heat exchanger? 9% When water freezes, how much does it expand in volume? ELC Which of the following coolants boasts the longest service life? Distilled Water Which of the following fluids transfers heat most efficiently? 100% What mixture concentricity of propylene glycol to water provides maximum antifreeze protection? 9.0 Which of the following pH readings taken in engine coolant fall in the normal range? never has to be inspected Which of the following is NOT true of an extended life coolant (ELC)? Counterflow Which type of radiator uses a double pass principle? Radiator Cap When truck radiator hoses collapse internally as an engine cools, which of the following components should be checked first? Water Pump Which component in a truck cooling system requires that the coolant has some lubricating properties? NTC thermostat What device is used to signal engine coolant temperatures on most current diesel engines? Shutters remain open In an older truck cooling system using Radiator shutters, what would happen if the air supply to the shutterstat failed? A/C to fan-engage command Which of the following could be handled by a data bus communications in a current diesel engine cooling system? Technician a only Tech A says that diesel engines equipped with water manifolds have more even actual cylinder temperatures. Tech B says that in engines not equipped with water manifolds, the cylinders closest yo the radiator are likely to run warmer when the engine is at operating temperatures. Who is correct? Tech B only Tech A says that downflow radiators use a double pass flow principle. Tech B says that a counterflow radiator uses double pass flow routing? Who is correct? Belt tension gauge What should always be used to adjust fan belts? Tech B only Tech 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. Tech B says that an engine overheat condition could be a missing or damaged radiator shroud. Who is correct? WEC Which type of engine coolant offers the best protection against liner cavitation erosion? Roots blower Which of thr following intake dystem components would be exclusively associated with a 2-stroke cycle diesel engine? 15 inches H2O What would be a typical maximum intake restriction specification for a naturally aspirated diesel engine? Volute What is the critical flow area inside the turbine housing of a turbocharger known as? Dial indicator What should be used to measure the radial play of a turbine shaft. 5 minutes After running a diesel engine under heavy load, how long should the engine be idled before shutdown? Ram air What is used to cool an air-to-air charge air cooler? Engine coolant What is used as the cooling medium in heat exchanger known as after coolers and intercoolers? Turbocharger Which of the following components makes detailed tuning of diesel engine intake manifolds unnecessary? Parallel port valve configuration Which of the following would ensure that the breathing efficiency of a pair of intake valves on one diesel engine cylinder was identical? Wastegate Which of the following components would be associated with a variable geometry turbocharger? high pitched whistle Which of the following is often an indication of a boost side, turbocharger air leak? Outside When a rain cap is used on a vertical exhaust stack, in which direction should the opening flap be pointed? Vane pitch When the unison ring in a variable nozzle (VN) type turbocharger is moved, which of the following changes? Resonation Which sound dampening principle is based on sound waves being reflected back towards their source? Diesel particulate filter (DPF) Where would you most likely find a thermocouple pyrometers on a current highway diesel engine? 900°C Which of the following would be a typical operating temperature of a diesel engine oxidizing converter? Dilutes the intake charge Which of the following best describes the role of an exhaust gas recirculation (EGR) system on a current diesel engine? Parallel port Which type of valve configuration is more likely to be used with quiescent combustion technology? Axial power turbine (APT) What term do DDC use to describe their compound turbocharger on DD-series engines? Insulation to maximize rejected heat discharged to the turbine housing What is the function of the stainless steel liner used in the cylinder head exhaust tract of some diesel engine cylinder heads? Engine retarding What is another way of saying engine braking? Internal compression brake Which of the following describes a brake in which the retarding force is the upstroke of the engine piston on its compression stroke? Energy absorbing compressor When an internal engine compression brake is actuated, what role does the engine play? At the highest engine rpms When is the braking efficiency of any engine brake usually at its highest? Around TDC on compression stroke When Jacobs internal engine compression brake is actuated, at what point is cylinder compression dumped into the exhaust circuit? Smart When an engine brake is actuated as part of cruise control management, what is the term sometimes used to describe the cruise control system? Minimal flow When a William type exhaust brake is fully actuated, which of the following is true of the exhaust flow area through the break? Hydromechanical What force is used to open the exhaust valves on a typical internal engine compression brake? Engine rpm Which of the following can be used by the driver to control the cycling of a typical internal engine compression brake? Valve train movement 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? Service brake application pressure switch For a truck driver to actuate a typical internal engine compression brake, all of the following switches would have to be closed EXCEPT: No fuel When an engine brake is actuated on a current truck diesel engine, what is the maximum fueling permitted? Three When 100% engine braking is required of a Cummins Intebrake on a pre-2010 ISX engine, how many solenoids must be energized? Tech A only Tech A says that an advantage of Cummins In the brake on a pre- 2010 ISX engine is progressive retarding that options engine braking from one through all 6 engine cylinders. Tech B says that on this engine, Intebrake effects braking using both of its overhead camshaft. Who is correct? Braking cycles through entire rpm range Which of the following is NOT an advantage of a Mercedes-Benz constant throttle valve (CTV) type engine brake? Constant throttle valve From where does cylinder gas blowdown occur during a CVT braking cycle? Tech A only Tech A says that most current engine brakes use the ECM to manage braking cycles. Tech B says that modern engine brakes can perform the majority of the braking requirements of a transport truck. Who is correct? Dual stage Which of the following terms describes an engine brake in which both upward strokes of the engine pistons are retarding strokes?