Lesson 1Common heavy-equipment diesel configurations (inline, V, turbocharged)This lesson reviews typical diesel engine setups in heavy equipment. It compares inline and V-type engines, turbocharged versus naturally aspirated options, and how these choices impact installation, access for servicing, and overall performance on Kiwi worksites.
Inline versus V engine architectureTurbocharged vs naturally aspirated dieselsWet and dry liner block constructionOverhead cam vs cam-in-block layoutsPower density and torque curve traitsService access and packaging concernsLesson 2Fuel system components: tanks, filters, lift pumps, injection pumps, injectorsExplore diesel fuel storage and delivery from tank to injector. Learn about component roles, fuel flow paths, pressure levels, filtration methods, common wear problems, contamination risks, diagnostic procedures, and safe servicing practices for heavy gear.
Tank design and venting in heavy equipmentLift pumps and low-pressure fuel circuitsFilter types, ratings, and water separationHigh-pressure injection pumps and controlInjector types, spray patterns, and wearFuel contamination causes and diagnosisLesson 3Lubrication system: oil types, filters, oil galleries, pressure systems, contamination signsDelve into the lubrication system from sump to bearings. Understand oil specifications, additives, filters, oil passages, pressure management, contamination origins, sampling techniques, wear detection, and service schedules tailored for heavy machinery in NZ conditions.
Engine oil grades and service ratingsOil pump types and pressure regulationMain galleries, jets, and lube pathsFilter media, bypass valves, and serviceContamination sources and oil samplingLow oil pressure and noise diagnosisLesson 4Air intake and turbocharging: filters, intercoolers, turbocharger diagnosticsExamine air intake routes, filtration, and turbocharging in heavy diesel engines. Cover filter varieties, charge-air cooling, turbo parts, boost regulation, failure indicators, and detailed diagnostic steps for turbochargers on site.
Air filter types, ratings, and restrictionTurbocharger components and terminologyWastegates, VGTs, and boost controlIntercoolers and charge-air leak testingTurbo failure symptoms and root causesBoost pressure and airflow diagnosticsLesson 5Common failure modes and symptoms mapping (smoke colours, odours, loss of power, overheating)Connect typical diesel failure patterns to visible symptoms. Discuss smoke colours, smells, noises, power reduction, and overheating, with systematic checks to pinpoint issues before major disassembly or testing in the field.
Black, blue, and white smoke diagnosisFuel, oil, and coolant odour indicatorsLoss of power under load troubleshootingOverheating and coolant loss patternsAbnormal engine noises and vibrationBasic fault isolation flowchartsLesson 6Engine sensors and controls: MAP/MAP-equivalents, coolant temp, oil pressure, crank/cam positionInvestigate vital engine sensors and control systems in modern diesels. Detail MAP sensors, temperature, pressure, and position sensors, basic wiring, ECM functions, failure types, and safe testing methods to read sensor data accurately.
MAP and boost pressure sensor operationCoolant temperature and fan control inputsOil pressure sensing and protection logicCrank and cam position sensor principlesECM strategies for fuelling and timingBasic sensor testing with multimetersLesson 7Cooling system: radiators, coolant types, thermostats, water pumps, hosesUnderstand engine cooling system design and function. Cover coolant chemistry, radiators, thermostats, pumps, hoses, and caps, including cavitation, electrolysis, leak detection, overheating diagnosis, and maintenance tips for rugged NZ environments.
Coolant types, additives, and mixing rulesRadiator construction, flow, and cleaningThermostats, bypass circuits, and testingWater pump design, drive, and failuresHoses, clamps, and pressure cap checksOverheating diagnosis and leak detectionLesson 8Diesel engine thermodynamic principles and four-stroke cycleIntroduce diesel thermodynamics and the four-stroke process. Relate compression ignition, air-fuel mixing, and heat management to torque, efficiency, emissions, and performance impacts from varying loads, altitude, and temperatures common in NZ.
Compression ignition and diesel propertiesIntake, compression, power, exhaust strokesCombustion phasing and pressure curvesAir–fuel ratio, mixture formation, and smokeHeat transfer, efficiency, and power outputEffects of load, altitude, and temperatureLesson 9Exhaust and aftertreatment basics: mufflers, particulate filters, DOC, sensors (if present)Overview of exhaust flow and aftertreatment in contemporary diesels. Explain mufflers, DOCs, DPFs, sensors, regeneration processes, backpressure problems, inspection areas, and safe management of heated parts during service.
Exhaust routing and backpressure effectsMuffler types and noise control methodsDOC function and light-off conditionsDPF loading, regeneration, and ashExhaust temperature and pressure sensorsAftertreatment fault symptoms overview
