Advanced Engine Theory
This thermodynamic principle explains why diesel engines achieve higher thermal efficiency than gasoline engines.
What is the higher compression ratio in the Diesel cycle?
This component adjusts boost pressure to prevent overboost in turbocharged engines.
What is the wastegate or VGT actuator?
A diesel engine cranks but doesn’t start. This is the first system you should check.
What is the fuel delivery system?
This system injects urea into the exhaust stream to reduce NOx
What is the SCR system?
A truck loses power climbing hills but runs fine on flat roads. What’s a likely cause?
What is a failing turbocharger or boost leak?
This term describes the delay between fuel injection and combustion.
What is ignition delay?
This sensor measures the mass of air entering the engine.
What is the MAF sensor?
This code indicates a malfunction in the EGR flow.
What is P0401?
This sensor monitors the efficiency of the DPF.
What is the differential pressure sensor?
A diesel engine shows excessive black smoke under load. What’s the most probable issue?
What is over-fueling or restricted air intake?
This effect causes uneven fuel distribution in direct injection systems at high RPMs.
What is the wall-wetting effect?
This system uses a variable geometry turbocharger and EGR to optimize combustion.
What is an air management system or advanced EGR strategy?
This test compares cylinder contribution to identify misfires.
What is a cylinder cut-out test?
This regeneration method uses post-injection to raise exhaust temperatures.
What is active regeneration?
A customer complains of poor fuel economy after a DPF replacement. What should you check?
What is forced regeneration frequency or sensor calibration?
This type of combustion occurs when fuel and air are not fully mixed before ignition.
What is diffusion combustion
This type of fuel injection system allows for multiple injections per cycle.
What is common rail direct injection?
This tool is used to measure injector balance rates.
What is a diagnostic scan tool or injector balance test tool?
This failure mode can cause DEF crystallization and system clogging.
What is improper DEF storage or dosing?
A technician finds metal shavings in the fuel filter. What’s the likely root cause?
What is high-pressure fuel pump failure?
This phenomenon can cause piston crown erosion due to improper injection timing.
What is impingement or fuel spray impingement?
This parameter must be precisely controlled to avoid knocking and ensure complete combustion.
What is injection timing?
A high-pressure fuel system leak may cause this symptom under load.
What is power loss or hesitation?
This component oxidizes hydrocarbons and CO before they reach the DPF.
What is the diesel oxidation catalyst or DOC?
The first diesel engine ran on this type of oil.
What is peanut oil?