GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Sunfire 🢒 Engine 🢒 Engine Controls - 2.2L 🢒 Detonation/Spark Knock

Detonation/Spark Knock

Checks

Action

DEFINITION: A mild to severe ping, usually worse during acceleration. The engine makes sharp metallic knocks that change with throttle opening.

Preliminary Checks
    • Refer to Symptoms .
    • Search for service bulletins.

Fuel System
    • Check for low fuel pressure. Refer to Fuel System Diagnosis .
    •  Check for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Check fir items that can cause an engine to run lean. where long term fuel trim significantly in the positive range. Refer to Diagnostic Aids for DTC P0171 Fuel Trim System Lean .

Ignition System
    • Check the spark plugs for proper heat range and reach. Refer to Maintenance Items in General Information.
    • Check the knock sensor (KS) system for no retard timing.

Engine Cooling System

Check for obvious overheating problems:

    • Low engine coolant
    • Restricted air flow to the radiator, or restricted water flow through the radiator
    • Inoperative electric cooling fan circuits
    • Correct coolant solution should be a 50/50 mix of DEX-COOL® or equivalent antifreeze coolant and water. Refer to Engine Overheating in Engine Cooling.

Engine Mechanical
    • Excessive oil in the combustion chamber-Leaking valve seals. Refer to Oil Consumption Diagnosis in Engine Mechanical.
    • Low cylinder compression. Refer to Engine Compression Test in Engine Mechanical.
    • Combustion chambers for excessive carbon buildup. Clean the chambers using a good-quality engine cleaner. Follow the instructions on the container.
    • For incorrect basic engine parts. Inspect the following:
       - The camshaft
       - The cylinder heads
       - The pistons
       - Other engine parts, as appropriate
    • Refer to Base Engine Misfire Diagnosis in Engine Mechanical.

Additional Checks
    • Check the transaxle range switch input with the vehicle in Drive and with the gear selector in Drive or Overdrive.
    • Check the torque converter clutch (TCC) operation. Applying the TCC too soon can cause the engine to spark knock. Refer to Torque Converter Diagnosis in Automatic Transaxle 3T40.
    • If the scan tool readings are normal and there are no engine mechanical malfunctions, fill the fuel tank with a known quality gasoline that has a minimum octanerating of 87 and re-evaluate the vehicle performance.