Define gas engine.
An engine that burns gasoline to produce power.
Define diesel engine.
An engine that burns diesel fuel for combustion and power.
True or false: Diesel engines are generally more fuel-efficient than gas engines.
TRUE
Diesel engines have higher thermal efficiency due to higher compression ratios.
What is the purpose of the fuel injector?
To deliver fuel into the combustion chamber in precise amounts.
Fill in the blank: The spark plug ignites the air-fuel mixture in a ______ engine.
gasoline
What does compression ratio indicate?
The ratio of the maximum to minimum cylinder volume in an engine.
Define cylinder head.
The component that closes the top of the cylinder and houses valves.
What is the role of the catalytic converter?
To reduce harmful emissions from the exhaust gases.
True or false: A turbocharger increases engine power by forcing more air into the combustion chamber.
TRUE
Turbochargers utilize exhaust gases to spin a turbine that compresses intake air.
What is the function of the oil pump?
To circulate engine oil for lubrication and cooling.
Fill in the blank: The radiator helps to ______ the engine by dissipating heat.
cool
What does OBD-II stand for?
On-Board Diagnostics II, a system for self-diagnosing vehicle issues.
Define fuel system.
The system that stores and delivers fuel to the engine.
What is the purpose of the exhaust system?
To direct exhaust gases away from the engine and reduce noise.
True or false: A misfiring engine indicates issues with the ignition system?
TRUE
Misfires can result from faulty spark plugs or ignition coils.
What is a timing belt?
A belt that synchronizes the rotation of the crankshaft and camshaft.
Fill in the blank: The intake manifold directs air into the ______.
cylinders
What is the function of the coolant?
To absorb and transfer heat away from the engine.
Define diagnostic trouble code (DTC).
A code generated by the OBD system indicating a fault in the vehicle.
What is the role of the mass air flow sensor?
To measure the amount of air entering the engine for optimal fuel injection.
True or false: Regular maintenance can prevent major engine repairs.
TRUE
Routine checks can identify issues before they escalate.
What does engine knock indicate?
An abnormal combustion process that can damage the engine.
Fill in the blank: The fuel pump delivers fuel from the tank to the ______.
engine
What is a compression test used for?
To assess the health of an engine’s cylinders.
