Exam 14: Air Induction and Crankcase Ventilation Systems

What is the auto-ignition temperature of diesel fuel?

Diesel engines are able to use a large amount of _____ to enhance engine breathing and performance characteristics.

To identify a problem in the intake system, what are most electronically controlled engines equipped with?

Technician A says that electric intake heaters are used to reduce cold-start and warm-up emissions. Technician B says that intake air heaters help to shorten the cranking time of a cold engine. Who is correct?

The results of an oil sampling of a diesel engine show high silicate levels. Which of the following could be the cause?

High intake temperatures can cause thermal damage to:

Less exhaust soot and hydrocarbon emissions are produced during cold start and warm-up when using:

Which of the following reasons best explains why air induction system noise is louder on a diesel engine than on a gasoline-fueled engine?

The subject of construction features of the air intake system are being discussed. Technician A says that the controls for regulating intake air temperature and EGR flow are commonly found in the air intake system. Technician B says that intake air systems have unique features to minimize the aspiration or entry of water and dirt. Who is right?

Which of the following sensors measure the weight of air entering the engine and are located after the air filter and before the turbocharger?

Technician A says that excessive black or gray smoke emissions from DPF (Diesel Particulate Filter) equipped engines may be caused by restricted air inlet systems or inadequate airflow into the engine. Technician B says that intake temperatures from the intake air sensor are used to modify fuel-injection timing and fuel rates to minimize emissions. Who is right?

What effect will high inlet air temperature combined with high humidity have on engine performance?

What happens to the mass of intake airflow into an engine when the EGR is enabled?

Which of the following information need NOT be collected by the technician when taking an oil sample?

Technician A says that frequent air filter changes help maintain the cleanest quality of air that enters the engine. Technician B says that dirty filters are better than clean filters at allowing cleaner air to enter the engine. Who is correct?

Which air filter element will provide the highest filtration efficiency (i.e., which removes the most dirt)?

An engine had a fault code for high crankcase pressure, and its power is derated. Technician A says that the crankcase filter could have frozen when it was exposed to extreme cold conditions. Technician B says that a frozen filter would likely blow engine gaskets and seals rather than cause a derate condition. Who is correct?

Which of the following is used on some EGR-equipped diesel engines to increase the rate of exhaust gas flowing into the cylinders under some conditions?

By doing which of the following does fuel disperse better horizontally, increasing the degree of swirl?

Which of these systems is impractical to use as a power booster in a diesel engine because the excess air factor diesels operate under would require tremendous amounts of air?