Inspections 
 | Action 
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DEFINITION: A steady pulsation or jerking that follows engine speed, which is usually more pronounced as the engine load increases. This condition is not normally felt above 1,500 RPM or 48 km/h (30 mph). The exhaust has a steady spitting
sound at idle or at low speed. 
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Preliminary 
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|     •  | Inspect the engine control system grounds for being clean, tight, and in the correct locations. Refer to 
Engine Controls Schematics
 . Ensure the resistance between the engine control module (ECM) housing
and the battery negative cable is less than 0.5 ohm. |  
  
|     •  | Verify that the ECM and ECM bracket fasteners are at the correct torque. |  
  
|     •  | Inspect the intake air duct and air cleaner outlet resonator for the following conditions: |  
  
|        -  | Improperly installed hoses |  
  
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Fuel System 
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Sensor/System 
 | Monitor the knock sensor (KS) system for excessive spark retard activity with a scan tool. Refer to 
Knock Sensor (KS) System Description
 , 
DTC P0327 or P0332
 , and 
DTC P0328 or P0333
 . 
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Ignition System 
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|     •  | Inspect for the correct installation of the ignition coil seals. Incorrect installation may allow water to enter the spark plug area. Inspect for moisture and corrosion. |  
  
|     •  | Remove the spark plugs and inspect for the following conditions: |  
  
|        -  | Refer to the following procedures: |  
  
|     •  | If the spark plugs are gas, coolant or oil fouled, determine the cause before replacing the spark plugs. Refer to the following procedures: |  
  
|        -  | For diagnosis of coolant contaminated spark plugs, refer to 
Loss of Coolant
 . |  
  
|     •  | Inspect the spark plug boots and terminals for burning or micro-arcing, corrosion, and damage to the insulation. |  
  
|     •  | Inspect the crankshaft position (CKP) sensor for the correct resistance. The sensor resistance may be out of range after a hot soak. Measure that the resistance remains within 700-1,200 ohms at all temperatures. |  
  
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Engine Mechanical 
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|     •  | Inspect for a condition with the camshaft actuator system. A camshaft actuator that is stuck in the full advance or retard position may cause this symptom. Refer to 
DTC P0011, P0014, P0021, or P0024
 . |  
  
|     •  | Inspect for the following engine mechanical conditions: |  
  
|        -  | Excessive oil in combustion chamber or leaking valve seals |  
  
|        -  | Incorrect cylinder compression |  
  
|        -  | Sticking or leaking valves  |  
  
|        -  | Excessive carbon buildup in the combustion chambers. Clean the chambers with top engine cleaner. Follow the instructions on the can.  |  
  
|        -  | For more information, refer to the following procedures: |  
  
|     •  | Inspect the following components for incorrect basic engine parts: |  
  
|        -  | Pistons, connecting rods, or bearings.  |  
  
|        -  | Refer to the following procedures: |  
  
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Additional 
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|     •  | Inspect the following exhaust system components: |  
  
|        -  | The exhaust system for damage |  
  
|        -  | The mufflers for heat distress or possible internal failure |  
  
|        -  | The three-way catalytic converter(s) for restrictions. |  
  
|     •  | Electromagnetic interference (EMI) on the crankshaft position (CKP) sensor signal circuits can cause an engine misfire condition. You can usually detect EMI with a scan tool by monitoring the engine speed parameter. A sudden increase in the engine
speed parameter, with little change in actual engine speed indicates that EMI is present. Inspect for high voltage components near the ignition control circuits if a condition exists. Also, inspect the engine ground shield of the CKP sensor circuits. |  
  
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