Engine Oil Classification and Maintenance

Questions and Answers

Which organization classifies all engine oil sold in North America?

API

Which organization grades engine oils by viscosity?

SAE

What two principles of fluid friction are used by an engine lubricating system?

thick film and boundary

What is a common indicator that engine oil has become contaminated with diesel fuel?

blacker in color Signup and view all the answers

What is an indication that engine oil has become contaminated with engine coolant?

cloudy appearance Signup and view all the answers

Which of the following is an undesirable constituent of engine oil?

ash Signup and view all the answers

Which of the following properly defines viscosity?

resistance to shear Signup and view all the answers

What API oil classification is recommended for engines fueled by ultra low sulfur fuel?

C1-4 Signup and view all the answers

In which of the following applications is the use of a synthetic engine oil especially recommended?

extreme cold weather operation Signup and view all the answers

When should a diesel engine crankcase oil level be checked for the most accurate reading?

10 minutes after shutdown Signup and view all the answers

What type of engine oil pump is most commonly used on truck diesel engines?

external gear pump (only has one gear) Signup and view all the answers

Which of the following values would be typical of engine oil at operating temperatures?

230°F Signup and view all the answers

What type of oil pressure sensor is most commonly used on electronically managed diesel engines?

variable capacitance Signup and view all the answers

When an engine oil analysis profile indicates higher than normal levels of copper, which of the following components would more likely be at fault?

main bearings Signup and view all the answers

If a C1-4 engine lubricating oil was used in place of the OEM specified CJ-4, which of the following components could be damaged?

diesel particulate filter DPF Signup and view all the answers

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 engines. Who is correct?

False Signup and view all the answers

Technician A says that highway diesel engines equipped with EGR should use 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?

False Signup and view all the answers

Which of the following methods would produce the most reliable results when drawing a sample of lube oil analysis?

engine off, engine hot, syringe at mid sump level Signup and view all the answers

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?

False Signup and view all the answers

When an oil sample analysis indicates elevated levels of silicon, which of the following should be inspected first?

low pressure intake circuit for leaks Signup and view all the answers

How is rejected heat dissipated in a typical diesel engine?

40% to exhaust, 60% to cooling system Signup and view all the answers

When the heat of combustion is transmitted through a diesel engine block, what is the principle known as?

conduction Signup and view all the answers

Which of the following does NOT act as a heat exchanger?

False Signup and view all the answers

When water freezes, how much does it expand in volume?

9% Signup and view all the answers

Which of the following coolants boasts the longest service life?

ELC Signup and view all the answers

Which of the following fluids transfers heat most efficiently?

distilled water Signup and view all the answers

What mixture concentricity of propylene glycol to water provides maximum antifreeze protection?

100% Signup and view all the answers

Which of the following pH readings taken in engine coolant fall in the normal range?

9.0 Signup and view all the answers

Which of the following is NOT true of an extended life coolant (ELC)?

False Signup and view all the answers

Which type of radiator uses a double pass principle?

counterflow Signup and view all the answers

When truck radiator hoses collapse internally as an engine cools, which of the following components should be checked first?

radiator cap Signup and view all the answers

Which component in a truck cooling system requires that the coolant has some lubricating properties?

water pump Signup and view all the answers

What device is used to signal engine coolant temperatures on most current diesel engines?

NTC thermostat Signup and view all the answers

In an older truck cooling system using radiator shutters, what would happen if the air supply to the shutterstat failed?

shutters remain open Signup and view all the answers

Which of the following could be handled by data bus communications in a current diesel engine cooling system?

A/C to fan-engage command Signup and view all the answers

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 to the radiator are likely to run warmer when the engine is at operating temperatures. Who is correct?

False Signup and view all the answers

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?

False Signup and view all the answers

What should always be used to adjust fan belts?

belt tension gauge Signup and view all the answers

Tech A says that the first step to take when troubleshooting an engine overheating condition 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?

False Signup and view all the answers

Which type of engine coolant offers the best protection against liner cavitation erosion?

WEC Signup and view all the answers

Which of the following intake system components would be exclusively associated with a 2-stroke cycle diesel engine?

roots blower Signup and view all the answers

What would be a typical maximum intake restriction specification for a naturally aspirated diesel engine?

15 inches H2O Signup and view all the answers

What is the critical flow area inside the turbine housing of a turbocharger known as?

volute Signup and view all the answers

What should be used to measure the radial play of a turbine shaft?

dial indicator Signup and view all the answers

After running a diesel engine under heavy load, how long should the engine be idled before shutdown?

5 minutes Signup and view all the answers

What is used to cool an air-to-air charge air cooler?

ram air Signup and view all the answers

What is used as the cooling medium in heat exchangers known as aftercoolers and intercoolers?

engine coolant Signup and view all the answers

Which of the following components makes detailed tuning of diesel engine intake manifolds unnecessary?

turbocharger Signup and view all the answers

Which of the following would ensure that the breathing efficiency of a pair of intake valves on one diesel engine cylinder was identical?

parallel port valve configuration Signup and view all the answers

Which of the following components would be associated with a variable geometry turbocharger?

wastegate Signup and view all the answers

Which of the following is often an indication of a boost side turbocharger air leak?

high pitched whistle Signup and view all the answers

When a rain cap is used on a vertical exhaust stack, in which direction should the opening flap be pointed?

outside Signup and view all the answers

When the unison ring in a variable nozzle (VN) type turbocharger is moved, which of the following changes?

vane pitch Signup and view all the answers

Which sound dampening principle is based on sound waves being reflected back towards their source?

resonation Signup and view all the answers

Where would you most likely find thermocouple pyrometers on a current highway diesel engine?

diesel particulate filter (DPF) Signup and view all the answers

Which of the following would be a typical operating temperature of a diesel engine oxidizing converter?

900°C Signup and view all the answers

Which of the following best describes the role of an exhaust gas recirculation (EGR) system on a current diesel engine?

dilutes the intake charge Signup and view all the answers

Which type of valve configuration is more likely to be used with quiescent combustion technology?

parallel port Signup and view all the answers

What term do DDC use to describe their compound turbocharger on DD-series engines?

axial power turbine (APT) Signup and view all the answers

What is the function of the stainless steel liner used in the cylinder head exhaust tract of some diesel engine cylinder heads?

insulation to maximize rejected heat discharged to the turbine housing Signup and view all the answers

What is another way of saying engine braking?

engine retarding Signup and view all the answers

Which of the following describes a brake in which the retarding force is the upstroke of the engine piston on its compression stroke?

internal compression brake Signup and view all the answers

When an internal engine compression brake is actuated, what role does the engine play?

energy absorbing compressor Signup and view all the answers

When is the braking efficiency of any engine brake usually at its highest?

at the highest engine rpms Signup and view all the answers

When Jacobs internal engine compression brake is actuated, at what point is cylinder compression dumped into the exhaust circuit?

around TDC on compression stroke Signup and view all the answers

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 Signup and view all the answers

When a William type exhaust brake is fully actuated, which of the following is true of the exhaust flow area through the brake?

minimal flow Signup and view all the answers

What force is used to open the exhaust valves on a typical internal engine compression brake?

hydromechanical Signup and view all the answers

Which of the following can be used by the driver to control the cycling of a typical internal engine compression brake?

engine rpm Signup and view all the answers

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 Signup and view all the answers

For a truck driver to actuate a typical internal engine compression brake, all of the following switches would have to be closed EXCEPT:

False Signup and view all the answers

When an engine brake is actuated on a current truck diesel engine, what is the maximum fueling permitted?

no fuel Signup and view all the answers

When 100% engine braking is required of a Cummins Intebrake on a pre-2010 ISX engine, how many solenoids must be energized?

three Signup and view all the answers

Tech 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 6 engine cylinders. Tech B says that on this engine, Intebrake effects braking using both of its overhead camshaft. Who is correct?

False Signup and view all the answers

Which of the following is NOT an advantage of a Mercedes-Benz constant throttle valve (CTV) type engine brake?

False Signup and view all the answers

From where does cylinder gas blowdown occur during a CVT braking cycle?

constant throttle valve Signup and view all the answers

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?

False Signup and view all the answers

Which of the following terms describes an engine brake in which both upward strokes of the engine pistons are retarding strokes?

dual stage Signup and view all the answers

Study Notes

Engine Oil Classification and Properties

API: The organization that classifies all engine oils sold in North America.
SAE: Grades engine oils based on viscosity.
Viscosity: Defined as resistance to shear in engine oils.
Contamination Indicators:
- Diesel fuel contamination is indicated by a blacker oil color.
- Engine coolant contamination results in a cloudy appearance.
Undesirable Constituents: Ash is considered undesirable in engine oil.
Recommended API Classifications: C1-4 is advised for engines using ultra low sulfur fuel.

Engine Oil Systems and Maintenance

Fluid Friction Principles: Thick film and boundary are two principles utilized by engine lubricating systems.
Checking Oil Levels: Diesel engine crankcase oil levels should be checked 10 minutes after shutdown for accuracy.
Common Pump Type: External gear pumps (single gear) are generally used in truck diesel engines.
Oil Samples: The most reliable sampling for oil analysis should be with the engine off, hot, and the syringe at mid-sump level.

Heat Management in Diesel Engines

Heat Dissipation: 40% of heat is expelled through exhaust and 60% through the cooling system.
Conduction: The principal by which combustion heat moves through a diesel engine block.
Coolant Types: Extended Life Coolant (ELC) has the longest service life and is effective against liner cavitation erosion.

Radiator and Cooling System Dynamics

Cooling Components: The water manifold does not act as a heat exchanger, whereas counterflow radiators utilize a double pass principle.
Fluid Efficiency: Distilled water transfers heat most efficiently.
Standard Operating Temperatures: A diesel engine's operating temperature is typically around 230°F.

Turbocharging and Air Management

Turbocharger Components: The critical flow area is known as the volute, and a wastegate is associated with variable geometry turbochargers.
Air Intake Restrictions: Natural aspirated engines typically have a maximum intake restriction of 15 inches H2O.

Engine Braking Systems

Engine Braking: The process known as "engine retarding" improves braking efficiency when at high RPMs.
Internal Compression Brakes: Engage during the upstroke of the engine piston on its compression stroke, with energy absorption capabilities.

Coolant and Fluid Mechanics

pH Reading: A typical normal range for engine coolant is around 9.0.
Cooling Method: Ram air is used to cool air-to-air charge air coolers, while engine coolant functions in aftercoolers and intercoolers.

Technical Troubleshooting

Common Issues: Elevated levels of silicon in oil indicate an inspection of the low-pressure intake circuit for leaks.
Radiator Cap Inspection: Should be the first check when truck radiator hoses collapse as the engine cools.
Maintenance Practices: Full-flow oil filters should be primed after an oil change to avoid damage to the turbocharger.

Engine Technology and Innovations

Current Technologies: Variable nozzle turbochargers use unison rings to change vane pitch for better performance.
Sound Dampening Principles: Resonation reflects sound waves back toward their source for dampening purposes.
Internal Compression Brakes: These systems can maximize braking efficiency and maintain control through multiple engine RPMs.

Key Engine Components

Cooling Components: The water pump requires lubricating properties in coolant.
Electrical Control: Modern engine brakes utilize ECM to manage braking cycles effectively.
Valve Configurations: Parallel port configurations ensure identical breathing efficiency for intake valves on a diesel engine cylinder.

Miscellaneous

Engine Shutdown Procedures: After heavy loading, idling the engine for 5 minutes before shutdown is critical.
Temperature Measurements: Typical operating temperatures for diesel engine oxidizing converters reach 900°C.
Fuel Management: During braking events, maximum fueling is restricted to none to ensure efficiency.

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Description

This quiz covers the classification and properties of engine oil, focusing on API and SAE standards, as well as key aspects of engine oil systems and maintenance. Test your knowledge on viscosity, contamination indicators, and fluid friction principles related to lubricating systems.