🔧 Diesel Engine Basics
What causes low compression in a diesel engine?
How does common-rail injection differ from older systems?
Why is diesel injection timing important?
What are the symptoms of a clogged injector?
How do I test injection pump pressure?
What is the role of a glow plug?
How do I diagnose a bad fuel lift pump?
What makes diesel engines more fuel-efficient?
Why do diesel engines produce more torque at low RPM?
How can I check for cylinder leakage?
🛠️ Maintenance and Service Procedures
11. How often should I change diesel engine oil?
12. What’s the correct oil viscosity for heavy-duty diesels?
13. When should I replace the oil filter?
14. How do I inspect the air filter?
15. What is the service interval for fuel filters?
16. How do I reset the service reminder light?
17. What’s involved in a full PM inspection?
18. How do I schedule DPF maintenance?
19. What additives are safe for diesel engines?
20. How often should I grease chassis fittings?
⛽ Fuel System and Filtration
21. How do I bleed air from the fuel system?
22. What are signs of water in diesel fuel?
23. How often should I replace the fuel-water separator?
24. How do I clean fuel injectors?
25. What causes fuel filter clogging?
26. How can I prevent diesel gelling in winter?
27. What is the correct torque for fuel line fittings?
28. How do I diagnose a bad fuel pressure regulator?
29. What’s the procedure for priming an empty tank?
30. How do I test fuel rail pressure?
💨 Turbocharging and Emissions
31. Why is my turbocharger making noise?
32. How do I check for turbo boost leaks?
33. What causes excessive exhaust backpressure?
34. How do I force a DPF regeneration?
35. What are the symptoms of a failing EGR valve?
36. How often should I clean the DPF?
37. How do I test the MAP sensor?
38. What causes white smoke on acceleration?
39. How do SCR and DEF systems work?
40. Can I temporarily disable the EGR?
🌡️ Cooling and Lubrication
41. Why is my radiator cap losing pressure?
42. How do I pressure-test the cooling system?
43. What causes coolant to disappear without leaks?
44. How do I check for a blown head gasket?
45. What’s the lifespan of a water pump?
46. How do I diagnose a bad thermostat?
47. When should I flush the coolant?
48. What are signs of liner cavitation?
49. How do I inspect oil galleries for sludge?
50. What oil-cooler maintenance is required?
🔍 Diagnostics and Troubleshooting
51. How do I pull codes without a scanner?
52. What does P0299 mean on a Cummins?
53. How do I reset the ECM after repairs?
54. What steps in a rough-idle diagnosis?
55. How to track intermittent faults?
56. What causes limp-home mode?
57. How to interpret live-data PID streams?
58. How do I troubleshoot MIL light issues?
59. What’s the best multimeter setting for sensor tests?
60. How do I verify wiring harness integrity?
⚡ Electrical and Electronics
61. Why won’t my starter crank the engine?
62. How do I load-test a heavy-duty battery?
63. What are symptoms of a failing alternator?
64. How do I find a parasitic drain?
65. What causes ABS light to stay on?
66. How do I test a wheel-speed sensor?
67. How to repair corroded connectors?
68. What is the CAN bus and how to diagnose it?
69. How do I program a replacement key FOB?
70. Why are trailer marker lights flickering?
🔩 Transmission and Drivetrain
71. Why is my automatic transmission slipping?
72. How often should I change transmission fluid?
73. What causes hard shifts under load?
74. How do I adjust a manual-clutch pedal?
75. What are signs of a failing U-joint?
76. How to inspect the driveshaft balance?
77. How do I test a torque converter?
78. What causes differential overheating?
79. How to check ring and pinion backlash?
80. When to rebuild the transmission?
🛞 Brakes and Suspension
81. How do I bleed air from air-brakes?
82. What causes air dryer failure?
83. How to adjust slack-adjusters correctly?
84. Why is my ABS modulator sticking?
85. How do I test suspension airbags?
86. What are symptoms of a bad brake chamber?
87. How to detect frame cracks on trailers?
88. How do I measure ride-height settings?
89. What causes uneven brake shoe wear?
90. How often should spring hangers be greased?
🚚 Trailer and Chassis
91. How do I inspect the trailer kingpin?
92. What’s the procedure for trailer DOT inspection?
93. How to replace trailer air lines?
94. How do I torque trailer wheel nuts?
95. What causes trailer sway?
96. How do I greasе the fifth wheel?
97. Why is one trailer side dragging?
98. How to align tandem axles?
99. What are common trailer frame‐crack locations?
100. How to test trailer ABS modulator?