Exam 32: Intake and Exhaust Systems

What manages turbo output by controlling the amount of exhaust gas entering the turbine housing?

Technician A says turbocharging uses the heat energy in the engine's exhaust gases to drive a pump that compresses the intake air. Technician B says supercharging relies on the rotation of the engine to compress the air.

An engine can be either supercharged or turbocharged, but not both.

Superchargers are normally lubricated by engine oil through passages in the intake manifold.

Technician A says the air filter is designed to prevent engine fires in the event of a backfire. Technician B says the air filter assembly is also designed to help reduce the noise caused by the movement of intake air. Who is correct?

Before replacing an exhaust system component, Technician A soaks all old connections with a penetrating oil. Technician B checks the old system's routing for critical clearance points. Who is correct?

The butterfly valve in IMT systems is controlled by an electric motor or __________________ actuator.

The boost pressure of a supercharger is proportional to ______.

On European vehicles equipped with twinchargers, the turbocharger boosts power at low speeds and the supercharger boosts power at high speeds.

The higher the altitude, the lower the atmospheric pressure.

Technician A says the emission vacuum schematic for the vehicle can only be found in the factory service manual. Technician B says an emissions vacuum schematic is given on a decal under the hood. Who is correct?

Acoustic supercharging uses the pressure of the air bouncing back and forth between the closed intake valve and incoming air from the plenum to increase the amount of air drawn into the cylinders.

Technician A says a vacuum leak will cause an engine to run richer than normal. Technician B says a vacuum leak can cause an engine to detonate. Who is correct?

Technician A says the action of the wastegate is controlled directly by manifold pressure. Technician B says the wastegate is controlled by the PCM. Who is correct?

Technician A says the engine should idle for 20 to 120 seconds after a hard run to allow the  turbocharger shaft to cool. Technician B says if the vehicle has not been driven for a few days, start the engine up and run it at 2,000 to 2,500 rpm to flush the old oil out of the turbocharger bearings and oil lines. Who is correct?

Wet intake manifolds have __________________ passages cast directly in them.

When intake air is compressed, its temperature decreases significantly.

A twin scroll turbocharger uses two turbine wheels connected to a common shaft to improve performance and reduce lag.

Technician A says a catalytic converter may be tested with a pyrometer. Technician B says a converter may tested using an exhaust gas analyzer. Who is correct?

Technician A says the main advantage of a turbocharger is that it allows for an increase of power without a substantial decrease in fuel economy. Technician B says the use of exhaust gas to drive the turbocharger robs power from the engine when the vehicle is driven at low speeds. Who is correct?