-
Injector Sleeve Combustion-Leak Case Analysis: Why Fuel-System Aeration Can Originate Inside the Cylinder Head
2026-09-03
Case Type: Technical Injector Installation Case Analysis Application: Injector Sleeve / Cup Equipped Diesel Engine Diagnostic Focus: Combustion Leakage Into Fuel Passage Some diesel engines use injector sleeves or cups to separate the injector from coolant, fuel or cylinder-head passages. Failure of ...
-
Cranking-Voltage Case Analysis: Why a Healthy Static Battery Reading Does Not Prove the ECU and Injectors Receive Enough Voltage During Starting
2026-09-03
Case Type: Technical Starting Electrical Case Analysis Application: Electronically Controlled Diesel Engine Diagnostic Focus: Cranking Voltage / ECU Supply A battery may show a normal resting voltage yet fall significantly when the starter motor draws current. For electronically controlled diesel ...
-
Under-Valve-Cover Harness Case Analysis: Why Injector Electrical Faults Can Appear Only After Engine Heat Soak
2026-09-03
Case Type: Technical Electrical Case Analysis Application: Diesel Injector Internal Harness Diagnostic Focus: Heat-Related Harness Resistance Some diesel engines route injector wiring through or beneath the valve cover. This environment exposes the harness and connectors to heat, vibration and oil. ...
-
Intake-Throttle Case Analysis: Why a Diesel Engine Can Show EGR-Like Symptoms When the Air Throttle Sticks
2026-09-03
Case Type: Technical Air-Management Case Analysis Application: EGR-Equipped Diesel Engine Diagnostic Focus: Intake Throttle / Airflow Control Many modern diesel engines use an intake throttle for functions other than conventional gasoline-engine load control. Depending on design, it may assist EGR ...
-
Charge-Air Cooler Airflow Case Analysis: Why Normal Boost Pressure Does Not Prove Normal Intake-Air Density
2026-09-03
Case Type: Technical Charge-Air Thermal Case Analysis Application: Intercooled Diesel Engine Diagnostic Focus: Charge-Air Cooling / Heat Rejection Boost pressure is only one property of the intake charge. Temperature also influences air density. Compression Heats Intake Air Turbocharger compression ...
-
VGT Mechanism Case Analysis: Why Correct Actuator Position Does Not Prove Variable Vanes Are Moving Freely
2026-09-03
Case Type: Technical Turbo Control Case Analysis Application: Variable-Geometry Turbocharger Diagnostic Focus: Actuator vs Vane Mechanism A VGT actuator can report that it reached its commanded position while the internal vane mechanism remains restricted. Command, Actuator and Vanes Are Separate ...
-
Pre-Turbo Exhaust Leak Case Analysis: Why Low Boost Does Not Automatically Prove Turbocharger Wear
2026-09-03
Case Type: Technical Air/Exhaust Diagnostic Case Analysis Application: Turbocharged Diesel Engine Diagnostic Focus: Exhaust Manifold Leakage Before Turbine A turbocharger requires exhaust energy to drive its turbine. A leak before the turbine can reduce that energy without damaging the turbocharger ...
-
Boost-Sensor Contamination Case Analysis: Why a Healthy Turbocharger Can Be Controlled Incorrectly by a Biased MAP Signal
2026-09-03
Case Type: Technical Air-System Sensor Case Analysis Application: Turbocharged Diesel Engine Diagnostic Focus: MAP / Boost Sensor Contamination Turbocharger diagnosis often compares requested and reported boost pressure. But the reported value is only as reliable as the sensor measuring it. Deposits ...
-
Rail-Pressure Pulsation Case Analysis: Why Average Pressure Can Look Normal While Delivery Becomes Uneven
2026-09-03
Case Type: Technical Common Rail Dynamic Case Analysis Application: High-Pressure Diesel Fuel System Diagnostic Focus: Pressure Pulsation / Uneven Pump Delivery A scan tool may display a rail-pressure value close to the commanded target while the engine still shows unstable combustion. Average ...
Cases
