Excessive Smoke

DEFINITION
White, black, gray or blue smoke under load or at idle hot or cold engine.

PRELIMINARY CHECKS
- Refer to Important Preliminary Checks. Preliminary Checks
- Make sure the customer has an actual problem.
- Check fuel quality. Refer to Specific Gravity Check Under Fuel Delivery.
- CHECK: For air leaks in fuel supply to injection pump. Refer to System Diagnosis/Fuel Delivery. Testing and Inspection
- CHECK: Injection pump timing. Refer to Fuel Delivery. Adjustments
- CHECK: Injection nozzles. Refer to Fuel Delivery. Testing and Inspection

SENSOR
- CHECK: Engine Coolant Temperature (ECT) sensor - Using a scan tool, compare engine coolant temperature with ambient temperature on a cold engine.
- If coolant temperature reading is 5° greater than or less than ambient air temperature on a cold engine, check for high resistance in coolant sensor circuit or sensor itself. Refer to Diagnostic Trouble Code (DTC) 15/DTC Charts and compare resistance values. Testing and Inspection

- CHECK: Glow plug system operation. Refer to Glow Plug System. Testing and Inspection
- CHECK: Exhaust Gas Recirculation (EGR) system operation. Refer to Exhaust Gas Recirculation (EGR)/Emission Control Systems. Testing and Inspection

AIR INTAKE SYSTEM
- CHECK: Air cleaner and air intake ducts for restriction.
- CHECK: Restriction in intake manifold.

ENGINE MECHANICAL
- CHECK: For incorrect basic engine parts such as cam, heads, pistons, etc.
- CHECK: For excessive oil entering combustion chamber.

ADDITIONAL CHECKS
- CHECK: Service Bulletins for PROM updates. Refer to Programmable Read Only Memory (PROM). PROM - Programmable Read Only Memory