Engines

Tech a says that a crankshaft determines the stroke of an engine. Tech B says that the length of the connecting rod determines the stroke of an engine. Who is right? A. A only B. B only C. Both D. Neither

A

What is the difference between direct injection and indirect injection?

A direct injection diesel engine uses an injector that squirts fuel directly into the combustion chamber. An indirect injection diesel engine uses an injector that squirts fuel into a precombustion chamber next to the combustion chamber.

If an engine at sea level produces 100 horsepower, how many horsepower would it develop at 6,000 feet of altitude?

An engine loses 3% of its power for each 1,000 feet above sea level. Therefore, at 6,000 feet, an engine would lose 18% (3 × 6 = 18) or 18 hp. Therefore, if an engine develops 100 hp at sea level, that same engine will produce 82 hp when operating at 6,000 feet altitude.

An SOHC V-8 engine has how many camshafts? A. One B. Two C. Three D. Four

B

How many rotations of the crankshaft are required to complete each stroke of a four stroke cycle engine? A. 1/4 B. 1/2 C. One D. Two

B

The coolant flow through the radiator is controlled by the _______. A. Size of the passages in the block B. Thermostat C. Cooling Fan(s) D. Water pump

B

Two technicians are discussing the term turbo lag. Technician A says that it refers to the delay between exhaust leaving the cylinder and contacting the tur- bine blades of the turbocharger. Technician B says that it refers to the delay in boost pressure that occurs when the throttle is rst opened. Who is correct? A. A only B. B only C. Both D. Neither

B

When replacing a thermostat or water pump, coolant drained from the cooling system should be A. reused. B. disposed of properly or recycled. C. filtered and reinstalled after the repair. D. poured down a toilet.

B

Which of the following ignites diesel fuel in a warm diesel engine? A. Glow plugs B. Heat of compression C. Spark plugs D. A distributorless ignition system

B

True or False? A replacement plastic intake manifold may have a different design or appearance from the original factory-installed part.

TRUE

A/an _______ quiets the exhaust by smoothing out the high-pressure exhaust pulses and allowing them to be released at an even and constant rate.

muffler

The SAE rating reflects the _______ of the oil.

viscosity

How many rotations of the crankshaft are required to complete each stroke of a four-stroke cycle engine? A. One-fourth B. One-half C. One D. Two

B

Technician A says that a stuck-open wastegate can cause the engine to burn oil. Technician B says that a clogged positive crankcase ventilation (PCV) system can cause the engine to burn oil. Who is correct? A. A only B. B only C. Both D. Neither

B

As the percentage of antifreeze in the coolant increases, the: A. freeze point decreases (up to a point) B. Boiling point decreases C. heat transfer increases D. Freeze point increases

A

Cranking vacuum should be: A. 2.5 in hg or higher B. more than 25 in hg C. 17 to 21 in hg D. 6 to 16 in hg

A

Oil change intervals as specified by the vehicle manufacturer A. are maximum time and mileage intervals. B. are minimum time and mileage intervals. C. only include miles driven between oil changes. D. only include time between oil changes.

A

Tech A says that a crankshaft determines the stroke of an engine. Tech B says that the length of the connecting rod determines the stroke of an engine. Who is right? A. A only B. B only C. Both D. Neither

A

Torque specifications for many plastic intake manifolds are measured in A. pound-inches. B. pound-feet. C. ft-lb per minute. D. lb-ft per second.

A

Torque is expressed in units of ________ A. Pound-feet B. Foot-pounds C. Foot-pounds per minute D. Pound feet per second

A.

A good reading for a cylinder leakage test would be A. within 20% between cylinders B. All cylinders below 20% C. all cylinders above 20% D. all cylinders above 70% leakage and within 7% of each other

B

A normally aspirated automobile engine loses about _______ power per 1,000 feet of altitude. A. 1% B. 3% C. 5% D. 6%

B

A rotating force is called ___________. A. Horsepower B. Torque C. Combustion pressure D. Eccentric movement

B

A rotating force is called: A. horsepower B. Torque C. combustion pressure D. Eccentric Movement

B

A smoothly operating engine depends on: A. high compression on most cylinders. B. Equal compression between cylinders C. cylinder compression levels above 100 PSI D. compression levels below 100 PSI on most cylinders

B

All overhead valve engines _______. A. use an overhead camshaft B. have the overhead valves in the head. C. operate by the two-stroke cycle D. Use the camshaft to close the valves

B

A/an _______ mixture of water and coolant provides the best combination of freezing protection and heat transfer ability in coolant.

50/50

Technician A says that during a power balance test, the cylinder that causes the biggest RPM drop is the weak cylinder. Technician B says that if one spark plug wire is grounded out and the engine speed doesn't drop, a weak or dead cylinder is indicated. Which technician is correct? A. A only B. B only C. Both D. Neither

B

The W in SAE 5W-20 Stands for: A. weight B. winter C. with D. without

B

A defective thermostat can cause the powertrain control module to set which of the following DTC? A. P0171 B. P0172 C. P0128 D. P0300

C

A good engine should produce how much compression during a running(dynamic) compression test at idle? A. 150-200 PSI B. 100-150 PSI C. 60-90 PSI D. 30-60 PSI

C

A water pump can fail to provide the proper amount of coolant flow through the cooling system if the A. coolant is leaking from the weep hole. B. bearing is noisy. C. impeller blades are worn or slipping on the shaft. D. shaft has become loose because of a bearing failure.

C

Horsepower is expressed in units of ________. A. Pound-Feet B. Foot Pounds C. Foot Pounds per minute D. Pound feet per second

C

Technician A says that a cracked exhaust manifold can affect engine operation. Technician B says that a leaking lower intake manifold gasket could cause a vacuum leak. Who is correct? A. A only B. B only C. Both D. Neither

C

Technician A says that any engine oil used should meet the vehicle manufac- turer's standards. Technician B says that the speci ed viscosity of oil should be used. Who is correct? A. Technician A only B. Technician B only C. Both Technicians A and B D. Neither Technician A nor B

C

Technician A says that some intake manifolds are plastic. Technician B says that some intake manifolds are constructed in two parts or sections: upper and lower. Who is correct? A. A only B. B only C. Both D. Neither

C

The air filter restriction indicator uses the _______ to determine whether it's time to replace the lter. A. number of hours of engine operation B. number of miles of vehicle travel C. amount of light that can past through the lter D. amount of restriction measured in inches of water

C

Two technicians are discussing oil pump operation. Technician A says that many oil pumps are driven directly from the front of the crankshaft. Technician B says that some are driven from the distributor if the engine uses a distributor-type ignition system. Who is correct? A. Technician A only B. Technician B only C. Both Technicians A and B D. Neither Technician A nor B

C

What service operation is most important on engines equipped with a turbocharger? A. Replacing the air lter regularly B. Replacing the fuel lter regularly C. Regular oil changes D. Regular exhaust system maintenance

C

Coolant is water and: A. Methanol B. Glycerin C. Kerosene D. Ethylene Glycol

D

Intake manifold gaskets on a V-type engine can fail from A. fretting. B. coolant damage. C. relative movement between the intake manifold and the cylinder head. D. all of the above.

D

One Cylinder of an automotive four-Stroke cycle engine completes a cycle every ________. A. 90 degrees B. 180 Degrees C. 360 Degrees D. 720 Degrees

D

Technician A says that glow plugs are used to help start a diesel engine and are shut off as soon as the engine starts. Technician B says that glow plugs are turned off as soon as a ame is detected in the combustion chamber. Who is correct? A. Technician A only B. Technician B only C. Both Technicians A and B D. Neither Technician A nor B

D

The upper radiator hose collapses when the engine cools. What is the most likely cause of this? A. Defective upper radiator hose B. Missing spring from the upper radiator hose C. Defective thermostat D. Defective pressure cap

D

What part should be removed to test cylinder compression on a diesel engine? A. Injector B. Intake valve rocker arm and stud C. Exhaust valve D. Glow plug

D

Some of the heavy metals found in used coolant include lead, aluminum, and _______.

Iron

What are the strokes of a four-stroke cycle?

The four strokes of a four-stroke engine includes intake, compression, power, and exhaust.

What are the three phases of diesel ignition?

The three phases of diesel ignition are: a. Ignition delay b. Rapid combustion c. Controlled combustion

What are the two most commonly used types of diesel injection systems?

The two most commonly used diesel injection systems include the distributor injection pump and the high-pressure common rail system.

Oil clearance between main and rod bearings represents a limited amount of _______ that the oil pump will normally handle while still maintaining oil pressure

leakage

The _______ inspection items that should be performed as part of a diagnosis include oil level and condition, coolant level and condition, oil-leak check, and engine-noise check.

visual