Table of Contents Preface Acknowledgments About the Author Chapter 1: History and Operation RPO Code First Generation (LB7) Second Generation (LLY) Third Generation (LBZ) Fourth Generation (LMM) Fifth Generation (LML) Sixth Generation (L5P) The "Other" Duramax Engines Engine Identification Lubrication System Cooling System Turbocharger System Glow-Plug System Crankcase Ventilation System EGR Electronic Throttle Valve The HPCR Fuel-Injection System Chapter 2: Engine Removal Chapter 3: Special Tools and Engine Disassembly Special Tools Precision Measuring Tools Valve-Spring Compressor Electronically Controlled Cooling Fan Engine Disassembly Glow Plugs Chapter 4: Inspection and Machine Work Engine Block Cleaning, Inspection, and Service Engine-Mount Hole Thread Inspection Freeze/Cup Plug Installation Camshaft and Bearing Inspection Camshaft Bearing Removal Oil Cooling Nozzle Removal Cylinder Bores Valvetrain Component Inspection 68 Crankshaft and Bearing Cleaning and Inspection Crankshaft Bearing Selection Injector Cleaning Cylinder-Head Disassembly and Inspection Valve-Guide Measurement, Reaming, and Valve Grinding Glow-Plug Bores Balancer Oil Pan Intake Manifold Flywheel Housing Front Cover Piston and Ring Inspection Connecting Rods Chapter 5: Assembly Measure the Camshaft Endplay Engine Oil-Pressure Sensor Engine Reinstallation Chapter 6: L5P Engine and Service Issues 2024 L5P Pistons 2024 L5P Head Gasket 2024 L5P Piston Cooling Nozzle Crankshaft Cylinder Heads and Valve Springs 105 L5P Turbocharger L5P Denso Fuel System 2017-Current Fuel-Rail Pressure Sensor Fuel-Level Sensor In-Tank Lift Pump High-Pressure Fuel Pump L5P Solenoid Fuel Injector Piezoelectricity Fuel Rails Engine Management Fuel-Injection Control Module DTC Retrieval and ECM Communication Misfire Detection and Cylinder Balance Analysis Injector Replacement and Calibration Codes Cylinder Balance Test: Related DTC Not Set Cylinder Firing Groups E35 Bosch ECM Sensor Overview Exhaust Aftertreatment System DPF Regeneration Selective Catalyst Reduction System Engine Diagnosis Cases Return Volume Test for High-Pressure System Duramax Engine Oil Checks Method to Check for Fluid in Oil Engine Oil Oil Filter Fuel Leaks.