Checks 
 | Action 
 | 
Definition: White, black, gray or blue smoke under load, idle or start up hot
or cold. 
 | 
Preliminary Check 
 | 
|     •  | Make sure the customer has an actual problem. |  
  
|     •  | Check the fuel quality. |  
  
 | 
Fuel System Checks 
 | 
|     •  | Check the injection pump. |  
  
 | 
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.  |  
  
 | 
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. |  
  
 |