Excessive Smoke. GMC Truck Yukon

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1997 🢒 Yukon - 4WD 🢒 Engine 🢒 Engine Controls - 6.5L 🢒 Excessive Smoke

Checks

Action

Definition: White, black, gray or blue smoke under load, idle or start up hot or cold.

Preliminary Check

•	Refer to Important Preliminary Checks .

•	Make sure the customer has an actual problem.

•	Check the fuel quality. Refer to Fuel Supply System Check .

Fuel System Checks

•	Check the injection pump.

•	Check the injection pump timing. Refer to Checking/Adjust Injection Timing .

•	Check the injection nozzles. Refer to Injection Nozzles .

Sensor Check

•

Check the Engine Coolant Temperature (ECT) sensor. Use the scan tool in order to compare the engine coolant temperature with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5° greater or less than the ambient air temperature on a cold engine, check for a high resistance in the coolant sensor circuit or the sensor itself.

•	Check the glow plug system operation.

Air Intake System Check

•	Check the air cleaner and the air intake ducts for restriction.

•	Check for a restriction in the turbocharger inlet duct.

•	Check for a restriction in the intake manifold.

Engine Mechanical Check

•	Check for incorrect basic engine parts such as the cam, the heads, the pistons, etc.

•	Check for excessive oil entering the combustion chamber.