Engine Repair and Performance Flashcards
6 cards from real ASE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Engine Repair and Performance flashcards as text
What is the primary function of the engine's timing belt or timing chain?
Answer: Synchronizes crankshaft and camshaft movement.
The engine's timing belt or timing chain is a critical component that ensures the precise synchronization of the crankshaft and camshaft(s). This synchronization is vital for opening and closing the engine's valves at the correct time relative to the piston's position. Proper timing is essential for efficient combustion and preventing valve-to-piston contact, which would cause catastrophic engine damage.
Which component is responsible for compressing air and fuel inside the cylinder before ignition?
Answer: Piston
The piston is a fundamental component within the engine cylinder that moves up and down. During the compression stroke, the piston travels upwards, compressing the air-fuel mixture against the cylinder head. This compression is essential for efficient combustion and generating power when the spark plug ignites the mixture, driving the engine's operation.
What is the main purpose of engine oil in an internal combustion engine?
Answer: Lubricates engine components to reduce friction.
Engine oil's primary role is to create a thin film between moving metal parts, such as pistons, crankshafts, and camshafts. This lubrication significantly reduces friction and wear, preventing premature component failure and heat buildup, which is crucial for the engine's longevity and efficient operation.
Which sensor monitors oxygen levels in the exhaust system for optimal fuel-air mixture?
Answer: Oxygen Sensor
The oxygen sensor, also known as the O2 sensor, is located in the exhaust system and measures the amount of unburned oxygen in the exhaust gases. This data is sent to the engine control unit (ECU), which then adjusts the fuel injection to maintain an optimal air-fuel ratio for efficient combustion and reduced emissions.
What is a symptom of a failing head gasket?
Answer: White smoke from exhaust.
A failing head gasket can allow coolant to leak into the combustion chambers, where it is burned along with the fuel. When coolant burns, it produces white, sweet-smelling smoke from the exhaust pipe, which is a classic indicator of a compromised head gasket.
What is the purpose of a turbocharger in an engine?
Answer: Increases power output by forcing more air into the engine.
A turbocharger uses exhaust gases to spin a turbine, which in turn drives a compressor. This compressor forces more air into the engine's cylinders than would naturally be aspirated, leading to more oxygen for combustion and thus a significant increase in power output and efficiency.