Excessive Smoke. GMC Truck GMC C-Series Medium Duty Truck B7 1998

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC C-Series Medium Duty Truck B7 🢒 Engine 🢒 Engine Controls - 6.5L (L65) 🢒 Excessive Smoke

Checks

Action

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

Preliminary Check

•	Refer to Symptoms .

•	Make sure the vehicle has an actual problem.

•	Check the fuel quality. Refer to Contamination Testing .

Fuel System Checks

•	Check the injection pump. Refer to Fuel Supply System Check .

•	Check the injection pump timing. Refer to Fuel Injection Pump Timing Adjustment .

•	Check the injection nozzles. Refer to Injection Nozzle(s) Diagnosis .

Sensor Check

•

Check the Engine Coolant Temperature (ECT) sensor by using 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 a restriction.

•	Check for a restriction in the turbo charger 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 any excessive oil entering the combustion chamber.