Detroit Diesel Troubleshooting Diagrams

To determine if improper engine coolant level is causing high engine coolant temperature, perform the following: ‪

1. Visually inspect the radiator coolant level; refer to OEM guidelines.
   1. If the radiator coolant level is within 2.0 in. (approximately 50 mm) of the radiator filler neck, check insufficient radiator air circulation;
   2. If the radiator coolant level is not within 2 in. (approximately 50 mm) of the radiator filler neck,

Improper Coolant Level Resolution

Perform the following steps to resolve improper coolant level: ‪

1. Fill coolant system to correct level;
2. Verify coolant level resolution;

Test Engine with Proper Coolant Level

Perform the following to determine if proper coolant level resolved high engine coolant temperature: ‪

1. Start and run the engine.
2. Run the engine through its operating range with no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range.
   1. If the engine coolant temperature is 88-96 ° C (190-210 ° F), no further troubleshooting is required. Shut down the engine.
   2. If the engine coolant temperature is not 88-96 ° C (190-210 ° F), shut down the engine. Check for insufficient radiator air circulation;

To determine if an improper injector calibration setting is causing excessive white smoke, perform the following: ‪

1. Check for improper injector calibration setting (DDEC III/IV engine only);
2. Check for improper injector setting repair;
3. Verify injector setting repair;

Test Engine with Corrected Injector Setting

Perform the following to determine if injector setting repair resolved excessive white smoke: ‪

1. Start and run the engine.
2. Run the engine at idle with a no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range.
3. Visually inspect exhaust for excessive white smoke.
   1. If the engine exhaust emission appears normal, no further troubleshooting is required. Shut down the engine.
   2. If the engine exhaust emission is excessively white, shut down the engine. Check for improper valve clearance or injector height, worn or damaged camshaft lobes and rollers

To determine if aerated fuel is causing excessive white smoke, perform the following steps: ‪

1. Disconnect the fuel line return hose from the fitting located at the fuel tank; refer to OEM guidelines.
2. Place the open end of the fuel line into a suitable container.
3. Start and run the engine.
4. Operate the engine at 1000 r/min.
5. Visually check to see if air bubbles are rising to the surface of the fuel within the container.
   1. If air bubbles are present, shut down engine;
   2. If air bubbles are not present, shut down engine, check for improper injector calibration setting;

Aerated Fuel Resolution

Perform the following to resolve aerated fuel: ‪

1. Tighten all fuel line connections between fuel tank and fuel pump; refer to OEM guidelines.
2. Visually inspect all fuel lines between fuel tank and fuel pump for leaks.
3. Repair damaged components as required; refer to OEM guidelines.
4. Verify aerated fuel resolution;

Test the Engine with Aerated Fuel Resolution

Perform the following to determine if aerated fuel resolution resolved excessive white smoke condition: ‪

1. Start and run the engine.
2. Run the engine at idle with a no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range.
3. Visually inspect exhaust for excessive white smoke.
   1. If the engine exhaust emission appears normal, no further troubleshooting is required. Shut down the engine.
   2. If the engine exhaust emission is excessively white, shut down the engine. Check for improper injector calibration setting;

To determine if the fuel pump is causing excessive white smoke, perform the following steps: ‪

1. Insert a piece of wire through the fuel pump flange drain hole
2. Crank the engine momentarily and feel for wire vibration.
   1. If the wire did not vibrate;
   2. If the wire did vibrate, check for aerated fuel;

Drive Hubs and Coupling Replacement

Perform the following for drive hubs or coupling replacement: ‪

1. Replace the drive hubs or coupling;
2. Verify the drive hubs and coupling replacement;

Engine Test with Replaced Drive Hubs or Replaced Coupling

Perform the following to determine if replaced drive hubs and coupling resolved excessive white smoke: ‪

1. Start and run the engine.
2. Run the engine at idle with a no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range.
3. Visually inspect exhaust for excessive white smoke.
   1. If the engine exhaust emission appears normal, no further troubleshooting is required. Shut down the engine.
   2. If the engine exhaust emission is excessively white, shut down the engine. Check for aerated fuel;

To determine if an improper grade of fuel oil is causing excessive white smoke, perform the following: ‪

1. Acquire a fuel oil sample from the vehicle fuel tank(s).
2. Submit fuel oil sample for an ASTM test analysis.
   1. If the fuel oil meets specifications, check the fuel pump;
   2. If the fuel oil did not meet specifications, resolve improper grade of fuel;

Improper Grade of Fuel Resolution

Perform the following steps to resolve the improper grade of fuel oil: ‪

1. Drain the fuel oil tank(s), refer to OEM guidelines, and dispose of properly.
2. Refill the fuel oil tanks with new fuel oil having a cetane number greater than 40.
3. Verify fuel oil resolution;

Test the Engine with New Fuel Oil

Perform the following steps to determine if the new fuel oil refill resolved the excessive white smoke condition: ‪

1. Start and run the engine.
2. Run the engine at idle with a no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range.
3. Visually inspect exhaust for excessive smoke.
   1. If the engine exhaust smoke emission appears normal, no further troubleshooting is required. Shut down the engine.
   2. If the engine exhaust smoke is excessively white, shut down the engine. Check the fuel pump;