Detroit Diesel Troubleshooting Diagrams

Prior to the removal of the cylinder head, refer to the appropriate sections of the service manual and remove the following items. ‪

• Turbocharger,
• Turbocharger oil supply tube,
• Turbocharger oil drain tube,
• Road draft tube,
• Exhaust manifold,
• ECM and mounting bracket, if equipped,
• Main wiring harness,
• Valve cover/Intake manifold,
• Fuel supply line to supply manifold from filter header,

Exploded View Cylinder Head and Related Parts

Repair or Replacement of Cylinder Head
To determine if repair is possible or replacement is necessary, perform the following procedure

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;

To determine if a defective turbocharger is causing excessive exhaust smoke, perform the following: ‪

1. Remove the turbocharger outlet line connected to the crankcase and place the drain line into a suitable container;
2. Perform a crankcase pressure test.
   1. If the engine crankcase pressure is greater than 3 in. H ₂ O (0.75 kPa), replace the turbocharger;
   2. If the engine crankcase pressure is 3 in. H ₂ O (0.75 kPa), call the Detroit Diesel Technical Service Group.

Turbocharger Replacement

Perform the following steps to replace a defective turbocharger: ‪

1. Remove defective turbocharger from the engine;
2. Tag removed turbocharger for remanufacture.
3. Install a new turbocharger to the engine;
4. Verify replacement of new turbocharger;

Test Engine with Replaced Turbocharger

Perform the following steps to determine if a replaced turbocharger resolved the excessive exhaust smoke condition: ‪

1. Start the engine.
2. Run the engine speed to full load.
3. Visually inspect the exhaust for excessive 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 excessive, shut down the engine. Call Detroit Diesel Technical Service Group.

To determine if a faulty fuel injector is causing the cylinder to misfire, perform the following steps: ‪

1. Install DDL adaptor to the data cable and plug the adaptor into the DDL connector in the vehicle; refer to OEM guidelines.
2. Start and run the engine at no-load.
3. From the DDEC III/IV Select Menu, scroll to select ENGINE and press the ENTER key.
4. Scroll to FUEL INJECTOR INFO (CUTOUT) and press the ENTER key.
5. Scroll to select NEW TEST and press the ENTER key.
6. Scroll to select RPM SETTING FOR CCO TEST NORMAL and scroll to select 1000 and press the ENTER key.
7. Scroll to select AUTO and press the ENTER key. Wait for END OF TEST.

Note: If an injector cannot be cutout, an ERROR message will appear. Press FUNC to exit the cylinder cutout function, press the FUNC key.

8. Scroll the list to review the results of the cylinder cutout test. To find suspect injectors, look for a cylinder with a value that is within 0.2 ° of the NO CUTOUT PULSE WIDTH, by comparing the CUTOUT PULSE WIDTH values to the NO CUTOUT PULSE WIDTH values.

If any CUTOUT PULSE WIDTH values are within 0.2 ° of the NO CUTOUT PULSE WIDTH, shut down the engine;
If any CUTOUT PULSE WIDTH values are not within 0.2 ° of the NO CUTOUT PULSE WIDTH, shut down the engine

To determine if a faulty exhaust system is causing excessive exhaust smoke, perform the following:

1. Drill an 11/32 in. hole in the exhaust pipe, 5 to 12 in. (127 – 305 mm) from the turbocharger exhaust outlet.

Note: The tapped hole must be in a comparatively straight area of the turbocharger exhaust outlet.

2. Tap the hole to accommodate an 1/8 in. pipe plug.
3. Connect a manometer to the tapped hole.
4. Start and run the engine.
5. Run the engine at idle with a no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range.
6. Run the engine speed to full load.

If the exhaust back pressure at full load is less than 3.0 in. Hg (10.1 kPa), check the fuel injectors.
If the exhaust back pressure at full load is 3.0 in. Hg (10.1 kPa) or greater

To determine if a charge air cooler is causing excessive exhaust smoke, perform the following: ‪

1. Attach a WK93 air-to-air charge air cooler test kit; refer to OEM guidelines.
2. Disconnect the air inlet hose from the outlet side of the turbocharger compressor housing;
3. Attach the air-to-air cooler test kit adaptor plug to fit into the hose at the compressor connector; refer to OEM guidelines.
4. Attach an air pressure hose to the air chuck at the regulator and gradually pressurize the air inlet system to a pressure of 25 · lb · in. 2 (177 kPa).
5. Apply a water and soap solution to each hose connection, across the face of the charge air cooler.
6. Apply a water and soap solution to the air intake manifold and cylinder head mating surface area.
7. Visually inspect all joints for air leaks and all charge air cooler welded surfaces for stress cracks

If air leaks are present around the joints, replace the charge air cooler;
If any leaks are present around the air intake manifold, repair the air intake manifold;
If no leaks are present, check for faulty exhaust system;