PIPE 3N3368 - Caterpillar

Probable Causes
Diagnostic codes
Electrical connectors
Air intake and exhaust system
Valve lash
Turbocharger
Fuel supply
Low compression (cylinder pressure)
Electronic unit injectors
Individual malfunctioning cylinderRecommended Actions
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
Note: The procedures have been listed in order of probability. Complete the procedures in order.Note: If the symptom only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high engine speed, full load, and engine operating temperature. Troubleshooting the symptom under other conditions can give misleading results.
Table 1
Troubleshooting Test Steps Values Results
1. Diagnostic Codes
Note: Certain diagnostic codes and/or event codes may cause poor performance.
A. Use the electronic service tool to check for active or logged codes.
Engine Derate or Diagnostic Codes
Result: A diagnostic code is present.
Repair: Troubleshoot the code.
Result: A diagnostic code is not present.
Proceed to Test Step 2.
2. Electrical connectors
A. Turn the start switch to the ON position.
B. Use the electronic service tool to check the intake manifold pressure.
C. Run the engine until the speed is equal to the maximum no-load speed.
D. Use the electronic service tool to make sure that the throttle is set to reach the maximum no-load speed.
Electrical connections
Result: The intake manifold pressure is not zero 0.5 kPa (zero 0.070 psi).
Repair: Check the 5 VDC sensor supply for the intake manifold pressure. Refer to Troubleshooting, "Sensor Supply - Test".
Result: All responses are normal.
Proceed to Test Step 3.
3. Air Intake and Exhaust System
A. Observe the check engine lamp. Check for an air filter restriction indicator, if equipped. Replace a plugged air filter. Refer to the Operation and Maintenance Manual.
B. Check the air inlet and exhaust system for restrictions and/or leaks.
Restrictions
Result: There are restrictions in the air inlet or exhaust system.
Repair: Make the necessary repairs, Refer to Systems Operation/Testing and Adjusting, "Air Inlet and Exhaust System - Inspect" for additional information.
Result: There are no restrictions in the air inlet or exhaust system.
Proceed to Test Step 4.
4. Valve Lash
Note: The valve lash can affect the performance of the engine.
A. Check the valve lash.
Valve lash
Result: The valve lash is not correct.
Repair: Check the valve lash. Refer to Systems Operation, Testing, and Adjusting, "Engine Valve Lash - Inspect/Adjust" for the correct procedure.
Result: The valve lash is correct.
Proceed to Test Step 5.
5. Turbocharger
Note: The turbocharger that is installed on the engine is a nonserviceable item. If any mechanical fault exists, then the faulty turbocharger must be replaced.
A. Ensure that the mounting bolts for the turbocharger are tight.
B. Check that the oil drain for the turbocharger is not blocked or restricted.
C. Check that the compressor housing for the turbocharger is free of dirt and debris. Make sure that the housing is not damaged.
D. Check that the turbine housing for the turbocharger is free of dirt and debris. Make sure that the housing is not damaged.
E. Check that the turbine blades rotate freely in the turbocharger.
F. Ensure that the wastegate on the turbocharger is adjusted correctly. Refer to Systems Operation, Testing, and Adjusting, "Turbocharger