1. Troubleshooting and Diagnosis Chapter 50
Instructor Name: (Your Name)

2. OBJECTIVES
Quarterback all engine troubleshooting using the OEM-recommended EST and online SIS.
Adhere to software-driven sequential troubleshooting paths to diagnose engine faults.
Interpret engine OEM expectations when diagnosing engine complaints.

3. OBJECTIVES (Cont.)
Understand when it is appropriate to think “outside the box.”
Use your technical and mechanical skills only when the OEM software fails to produce the root cause of a failure.
Analyze exhaust gas smoke emission by color.

4. OBJECTIVES (Cont.)
Relate some typical engine performance malfunctions to smoke color.
Outline step-by-step sequential troubleshooting practices.
Troubleshoot some typical engine and fuel system failures.

5. OBJECTIVES (Cont.)
Identify common operator and technician abuses of engine and fuel systems.
Develop a checklist for tackling lack of power complaints specific to an engine or chassis system.

6. OBJECTIVES (Cont.)
Profile some of the most common engine malfunction symptoms to typical causes.
Identify the role played by a DSM in providing product technical support.

7. INTRODUCTION
The term troubleshooting is generally used to describe noninvasive (meaning that as little of the engine is disassembled as possible) methods of determining the cause of an engine problem.

8. TROUBLESHOOTING TOOLS
EST loaded with the OEM diagnostic software and SIS
Serial link interface or communications adapter CA)
Wireless or wired Internet connection
Breakout boxes, Tees, terminal spoons, and a digital multimeter (DMM)

9. Possible Results of Failure to Observe OEM Diagnostic Routines
Denial of warranty
Excessive amounts of wasted troubleshooting time
Trial and error diagnostics: This common practice makes the whole industry look bad

10. Possible Results of Failure to Observe OEM Diagnostic Routines (Cont.)
Engine damage incurred by the troubleshooting itself
Costly comeback repairs

11. TECH TIP Never skip a software-guided diagnostic routine.
This happens all too often when a technician knows from experience the “probable cause” of a complaint.
This practice can actually result in extending the time spent troubleshooting and denial of warranty.

12. THINKING OUTSIDE THE BOX
Most challenging troubleshooting problems tend to be those that fall just outside the scope of the troubleshooting paths embedded in the OEM software.

13. Requires a Toolbox Of Technical Skills
Thorough understanding of a diesel engine’s mechanical systems
Thorough understanding of the engine’s computer control systems
OEM-specific training on the engine on which the technician is working

14. Requires a Toolbox of Technical Skills (Cont.)
Ability to navigate the online SIS using an EST and OEM software
Ability to navigate OEM wiring schematics and virtual schematics

15. ONLINE SERVICE INFORMATION SYSTEMS
All truck diesel engine OEMs require that technicians use online SISs to quarterback troubleshooting routines.

16. HD-OBD
This means that, in 2014, third-party ESTs must be able to access all covered fault codes to a repair level.

17. SMOKE ANALYSIS Clear. The exhaust gas stream is in a gaseous state.
White. Some liquid (water, coolant, or fuel) is condensing in the exhaust gas stream.
Black. Some solid matter (particulate soot) is contained in the exhaust gas.
Blue. This usually indicates presence of engine oil (condensed and partial soot) in exhaust gas.

18. BLACK SMOKE Insufficient combustion air Restricted exhaust
Exhaust gas recirculation (EGR) failure
Diesel particulate filter (DPF) failure

19. BLACK SMOKE (Cont.) Excess or irregular fuel distribution
Improper grade of fuel
Degraded fuel: CN definers boiled off

20. TECH TIP
When black smoke emission is caused by using fuel that has been stored for an excessive period (a problem in equipment used seasonally), the addition of a cetane improver will take care of the problem.
Cetane improvers should not be used for more than a tank of fuel because fuel and emission systems damage can occur.

21. Insufficient Combustion Air
The causes for insufficient combustion air are:
Air starvation caused by any performance defect in the air intake system components from the air filter, turbocharger, boost air/heat exchanger, plugged EGR or CGI heat exchanger, EGR or CGI control valve failure
Intake valve problems; clogged cylinder sleeve ports (two-stroke cycle engines); restricting emergency stop gate; and so on

22. Exhaust System Restriction
Exhaust system restriction problems can usually be related to:
Turbocharger failure
Collapsed exhaust system piping
Internal failure of engine silencer or catalytic converter
Plugged-up DPF
Exhaust brake malfunction

23. Excess Fuel/Irregular Fuel Distribution
Excess fuel (overfueling) or irregular fuel distribution can be caused by:
Out-of-spec injection timing (intentional or accidental)
Injector nozzle failure
Variable timing control device failure
Unbalanced fuel rack settings

24. Excess Fuel/Irregular Fuel Distribution (Cont.)
Lugging engine (operation at high loads at speeds below peak torque rpm)
Incorrect governor settings
Inoperative or tampered with manifold boost management system
Defective barometric capsule (altitude compensator)

25. Improper Fuel Grade
When fuel is stored for prolonged periods, the more volatile fractions evaporate, altering the fuel’s chemical characteristics.
Additionally, fuel suppliers seasonally adjust fuel to accommodate temperature extremes.
The use of used engine lube/fuel mixers often produces smoking.

26. TECH TIP
It is essential to use the correct ultra-low sulfur (ULS) fuel with engines using DPFs.
It appears that in some areas, pre-2007 LS fuel is still obtainable. This fuel can terminally destroy a DPF in as little time as 1 hour of operation.
Never use lube/fuel mixers with engines equipped with DPFs.

27. WHITE SMOKE
White smoke is caused by condensing liquid in the exhaust gas stream.

28. Cylinder Misfire
Check for a problem that can be read electronically first on electronically managed engines.
Perform an electronic cylinder cutout test using a personal computer (PC) or other EST if that option is in the software diagnostics.

29. CAUTION
Never attempt to disable the injectors mechanically on electronically-controlled diesel engines.

30. CAUTION
When cracking high-pressure pipes on hydromechanical engines, make sure that suitable eye and hand protection is worn and that spilled fuel is not in danger of igniting.

31. Low Cylinder Compression Pressure
These are usually mechanical problems that prevent the cylinder from sealing properly

32. Low CN Fuel
This is more likely to be a problem experienced by operators that bulk purchase fuel in large volumes and then store it for prolonged periods.

33. Air Pumped Through the High-Pressure Injection Pump Circuit
C heck the fuel subsystem, because this is usually the source of the air, depending on the type of system.

34. Coolant Leakage to Cylinders
Confirm that the emission truly is coolant. Engine coolant has an acrid, bittersweet odor that is very noticeable.
Locate the source. Some possibilities are injector cup failure, head gasket (fire ring) failure, cracked cylinder head, cracked wet liner flange, or cavitation perforation of wet liner.

35. BLUE SMOKE Some possible causes are: Turbocharger seal failure
Pullover of lube oil from oil bath air cleaner sump
Worn valve guides
Ring failure
Glazed cylinder liners
High oil sump level

36. BLUE SMOKE (Cont.) Excessive big end bearing oil throw off
Low-grade fuel
Fuel contaminated with automatic transmission fluid (ATF)
Engine lube placed in fuel tanks as an additive

37. SMOKE EMISSION MEASUREMENT
For many years, a number of state and provincial jurisdictions have set exhaust stack maximum smoke density standards.

38. TROUBLESHOOTING GUIDELINES
A set of guidelines will help the technician to strategize the troubleshooting procedure.
Engine OEMs produce some excellent troubleshooting charts for their own products.

39. International Truck Troubleshooting Strategy Chart

40. International Truck Troubleshooting Strategy Chart (Cont.)

41. LOW OIL PRESSURE Check the oil sump level.
Install a master gauge (an accurate, fluid-filled gauge).
Warm engine to operating temperature and check oil psi.
Investigate oil consumption history.
Determine the cause.

42. HIGH OIL CONSUMPTION Excess cylinder wall lubrication
External oil leaks
High oil temperatures
Piston ring failure

43. HIGH OIL CONSUMPTION (Cont.)
High oil sump level
Glazed cylinder liners or sleeves
Improper dipstick marking

44. HIGH OIL TEMPERATURE Insufficient oil in circulation
High water jacket temperatures
Plugged/failed oil cooler
Oil badly contaminated
Engine lugdown

45. COOLING SYSTEM PROBLEMS
Overheating
Overcooling
Loss of coolant
Defective radiator cap
Defective thermostat

46. TECH TIP
The reason diesel engine operating temperatures may run higher than expected in extreme cold may be due to the use of high concentration PG coolant.
High concentration PG solutions do provide increased antifreeze protection but also lower cooling efficiency, resulting in noticeably higher operating temperatures.

47. CYLINDER COMPRESSION PROBLEMS
Overall low or unbalanced cylinder compression can create problems of excessive blowby, low power, and vibration.
In electronically-managed engines, a cylinder balance test (a.k.a. cylinder contribution test) will usually identify cylinder compression problems rapidly and this is the preferred method of testing.

48. HIGH EXHAUST TEMPERATURE READINGS
When diagnosing high exhaust temperatures on highway diesel engines equipped with catalytic converters and DPFs, always use the engine OEM’s recommended procedure.

49. TECH TIP
Transient (temporary) high exhaust temperatures are normal on post-2007 trucks equipped with oxidation catalysts, dosed reduction catalysts, and DPFs.
During DPF regenerative cycles, transient high exhaust temperatures are normal (may cause a visible glow at night) and can be ignored unless they log a fault code.

50. SUDDEN ENGINE SHUTDOWN
Electrical failure
Air in fuel system
Water in fuel system
Plugged fuel line

51. ENGINE RUNS ROUGH Air in fuel system
Leak or restriction on the charge side of the fuel subsystem
Injection nozzle
CN value of fuel is too low
Fuel cloud point is high

52. ENGINE RUNS ROUGH (Cont.)
Advanced injection timing
Unbalanced cylinder fueling
Bent or broken EUI pushrod
Maladjusted valves
Cylinder leakage

53. ENGINE BLOWBY Cracked head or piston
Worn, stuck, or broken piston rings
Glazed liner/sleeve inside wall
Poor quality or degraded engine lube

54. ENGINE WILL NOT CRANK
Focus on the cranking circuit first, and eliminate any obvious causes.

55. TECH TIP
Use OEM software—guided troubleshooting whenever you can, even when you know the problem is not electronic.
These programs are designed to prevent technicians from overlooking a critical step in a troubleshooting procedure.

56. LACK OF POWER Restricted fuel filters Leaks in the boost air circuit
Low manifold boost
Restricted exhaust system
Low fuel subsystem charging pressure

57. LACK OF POWER (Cont.) Valve lash maladjustment
Defective boost pressure sensing and fuel control devices
Governor maladjusted
Contaminated fuel

58. ENGINE VIBRATION Cylinder misfire Loose vibration damper
Defective vibration damper
Defective external driven component

59. EGR CIRCUIT MALFUNCTIONS
Short to ground
Dead short
EGR valve position circuit fault

60. MANIFOLD BOOST PROBLEMS
Air system restriction upstream or downstream from turbocharger impeller
Air leakage downstream from turbocharger impeller
Low fuel delivery
Mismatched turbocharger

61. DPF MALFUNCTIONS Black smoke emission DPF collects excessive soot
DPF is restricted
DPF temperatures are high

62. DPF Restriction
The engine management electronics are designed to respond to DPF restriction caused by excessive soot dump by logging fault codes and power derate strategies.

63. High DPF Intake Temperatures
Restricted boost air heat exchanger
Air inlet restriction
Exhaust restriction
High altitude operation
Overfueling
Low coolant level

64. MECHANICAL ENGINE KNOCK
Bottom end knock
Failed crankshaft
Damaged gears
Failure of feedback circuit component

65. COMBUSTION KNOCK Fuel injection timing Air in fuel Low grade fuel
Injectors out of balance

66. FUEL PUMP/INJECTOR SCUFFING
Low power
Slight engine miss
Misfire
Smoking

67. TECH TIP
Caution truck drivers against adding excessive quantities of methyl hydrate and diesel fuel conditioners to fuel tanks.
Both form a solution with any water present in the fuel tank and the solution can bypass water separators to enter the high-pressure fuel injection circuit where it causes the scuffing damage.

68. TECH TIP
When a sensor logs an active fault code, try disconnecting the sensor and observing whether the FMI changes.
If there is no change, it suggests that the fault lies in the wiring circuit.
If the FMI changes, it suggests that the problem lies in the sensor.

69. DSM ROLE
The DSM is one of the first to take training on a new OEM engine series, because it then becomes a DSM responsibility to provide product support.
A good DSM collates questions and feedback and can usually provide answers to questions before they appear in online TSBs and SIS amendments.

70. HD-OBD
Heavy-duty onboard diagnostics (HD-OBD) is on schedule to come into effect on the first day of 2014.
This will force all engine OEMs to open up bus access to allow generic ESTs to communicate with J1939 to a repair level for any emissions-related problem.

71. HD-OBD Data Packet Structure

72. SUMMARY
The term troubleshooting describes a systematic procedure used to diagnose an engine or fuel system complaint.
All troubleshooting of electronically-managed engines should be guided by the OEM-recommended EST and online SIS.

73. SUMMARY (Cont.)
You must adhere to software-driven troubleshooting maps because they have been proven to reduce the time to diagnose the root cause of a complaint significantly .
Thinking inside the box means accepting software guided troubleshooting sequences and problem solving paths.

74. SUMMARY (Cont.)
Only when an engine problem falls outside of the OEM diagnostic routines should the technician resort to thinking outside the box.
The diesel technician should be able to analyze exhaust smoke emission and use this knowledge to help diagnose engine and fuel system malfunctions.

75. SUMMARY (Cont.)
White exhaust smoke indicates the presence of condensing liquid in the exhaust gas.
Black exhaust smoke indicates the presence of particulate in the exhaust gas.
Blue smoke emission is generally associated with an engine oil-burning condition.

76. SUMMARY (Cont.)
An opacity meter is a light extinction test instrument used by transportation regulation enforcement agencies to test exhaust smoke density to J1667 standards.
Work methodically through sequential troubleshooting procedures—Never skip a step on the basis of an assumption.

77. SUMMARY (Cont.)
Engine malfunctions have some common root causes regardless of the engine OEM. Learn some of the typical causes of everyday engine complaints.
HD-OBD becomes effective on the first day of 2014; this will require all engine OEMs to open up bus access to all emissions-related fields to generic ESTs.

78. SUMMARY (Cont.) Keep an open mind.
When seeking advice, seek the advice of an expert.

79. Any Questions ?
Thank You !