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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2004 🢒 Chevy K Silverado - 4WD 🢒 Engine 🢒 Engine Controls - 6.6L (LLY) 🢒 Excessive Smoke

Excessive Smoke White

Inspection

Action

DEFINITION: White smoke under load, idle or start up hot or cold.

Preliminary Inspection
    • Refer to Symptoms - Engine Controls .
    • Ensure the customer has an actual problem.
    • Check the coolant level in the reservoir. White coolant smoke may be mistaken for blue/gray smoke. If the coolant level is low refer to Loss of Coolant in Engine Cooling.
    • Compare the scan tool data at idle with the scan tool data list. Refer to Scan Tool Data List .

Fuel System Inspection
    • If excessive smoke is present, inspect for a stuck open fuel injector by performing the following procedure:
        1. Remove the ignition 1 relay.
        2. Remove the glow plugs. Refer to Glow Plug Replacement - Bank 1 and Glow Plug Replacement - Bank 2 .

        Important: Do not stand in front of the glow plug holes while cranking the engine.

        3. Crank the engine while observing the glow plug holes for fuel spray.
        4. Replace the fuel injectors for the cylinders that spray fuel.
        5. Inspect for contaminated oil or high oil level. Refer to Fuel in Engine Oil in Engine Mechanical - 6.6L.
    • Inspect the fuel injectors. Refer to Fuel Injector Balance Test with Tech 2 .

Sensor Inspection
    • Inspect the engine coolant temperature (ECT) sensor. Use the scan tool in order to compare the ECT with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5 degrees more or less than the ambient air temperature on a cold engine, inspect for a high resistance in the coolant sensor circuit or the sensor itself.
    • Turn ON the ignition with the engine OFF. Observe the actual fuel rail pressure with a scan tool. The actual fuel rail pressure should be between 1.0-1.8 MPa. If it is not, inspect for high resistance in the fuel rail pressure (FRP) sensor circuits or the FRP sensor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Air Intake System Inspection
    • Inspect the air cleaner and the air intake ducts for restriction.
    • Inspect for a restriction in the turbocharger charge air cooler.
    • Inspect for a restriction in the intake manifold. Refer to Intake Manifold Cleaning and Inspection in Engine Mechanical - 6.6L.

Engine Mechanical Inspection
    • Inspect for incorrect basic engine parts such as the cam, the heads, the pistons, etc.
    • Inspect for coolant entering the combustion chamber.

Excessive Smoke Black

Inspection

Action

DEFINITION: Black smoke under load, idle or start up hot or cold.

Preliminary Inspection
    • Refer to Symptoms - Engine Controls .
    • Ensure the customer has an actual problem.
    • Compare the scan tool data at idle with the scan tool data list. Refer to Scan Tool Data List .

Fuel System Inspection
    • Observe the actual vs. desired fuel rail pressure with a scan tool, with the engine running.
    • Inspect the fuel injectors. Refer to Fuel Injector Balance Test with Tech 2 .

Sensor Inspection
    • Inspect the engine coolant temperature (ECT) sensor. Use the scan tool in order to compare the ECT with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5 degrees more or less than the ambient air temperature on a cold engine, inspect for a high resistance in the coolant sensor circuit or the sensor itself.
    • Turn ON the ignition with the engine OFF. Observe the actual fuel rail pressure with a scan tool. The actual fuel rail pressure should be between 1.0-1.8 MPa. If it is not, inspect for high resistance in the fuel rail pressure (FRP) sensor circuits or the FRP sensor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Air Intake System Inspection
    • Inspect for a restriction in the air cleaner or the air intake ducts.
    • Inspect for a restriction in the turbocharger charge air cooler.
    • Inspect for a restriction in the intake manifold.
    • Inspect for an air leak in the charge air cooler with a J 46091 charge air cooler tester.
    • Inspect for an air leak in the air ducts between the turbocharger and the intake manifold.

Engine Mechanical Inspection
    • Inspect for incorrect basic engine parts such as the cam, the heads, the pistons, etc.
    • Inspect for excessive oil entering the combustion chamber. Refer to Oil Consumption Diagnosis in Engine Mechanical - 6.6L (LLY).

Excessive Smoke Gray or Blue

Inspection

Action

DEFINITION: Gray or blue smoke under load, idle or start up hot or cold.

Preliminary Inspections
    • Refer to Symptoms - Engine Controls .
    • Ensure the customer has an actual problem.
    • Check the coolant level in the reservoir. White coolant smoke may be mistaken for blue/gray smoke. If the coolant level is low refer to Loss of Coolant in Engine Cooling.
    • Compare the scan tool data at idle with the scan tool data list. Refer to Scan Tool Data List .

Fuel System Inspection
    • Observe the actual vs. desired fuel rail pressure with a scan tool, with the engine running.
    • Inspect the fuel injectors. Refer to Fuel Injector Balance Test with Tech 2 .

Sensor Inspection
    • Inspect the engine coolant temperature (ECT) sensor. Use the scan tool in order to compare the ECT with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5 degrees more or less than the ambient air temperature on a cold engine, inspect for a high resistance in the coolant sensor circuit or the sensor itself.
    • Turn ON the ignition with the engine OFF. Observe the actual fuel rail pressure with a scan tool. The actual fuel rail pressure should be between 1.0-1.8 MPa. If it is not, inspect for high resistance in the fuel rail pressure (FRP) sensor circuits or the FRP sensor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Air Intake System Inspection
    • Inspect the air cleaner and the air intake ducts for restriction.
    • Inspect for contamination of the mass air flow (MAF) sensor.
    • Inspect for a restriction in the turbocharger charged air cooler.
    • Inspect for a restriction in the intake manifold.

Engine Mechanical Inspection
    • Perform a cylinder leakage test.
    • Perform the engine compression test. Refer to Engine Compression Test in Engine Mechanical - 6.6L.
    • Inspect for incorrect basic engine parts such as the cam, the heads, the pistons, piston rings, and valves.
    • Inspect for excessive oil entering the combustion chamber. Refer to Oil Consumption Diagnosis in Engine Mechanical - 6.6L.

Turbocharger Inspection

Inspect for leaking seals in the turbocharger. A slight film on the intake side is normal.