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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 Cavalier 🢒 Engine 🢒 Engine Electrical 🢒 Detonation/Spark Knock

Detonation/Spark Knock

Checks

Action

DEFINITION: The engine makes a mild to severe pinging noise, which is usually worse during acceleration. The engine makes sharp metallic knocks that change with the throttle opening.

Preliminary Checks
    • Refer to Symptoms - Engine Controls .
    • Search the 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 for conditions that can cause an engine to run lean, where the long-term fuel trim is significantly in the positive range. Refer to Diagnostic Aids for DTC P0171 .

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

Engine Cooling System

Check for obvious overheating problems, including the following conditions:

    • Low engine coolant
    • Restricted air flow to the radiator
    • Restricted water flow through the radiator
    • Inoperative electric cooling fan circuits
    • Incorrect thermostat operation

The correct coolant solution should be a 50/50 mix of Dexcool® or an equivalent mixture of antifreeze coolant and water. Refer to Thermostat Diagnosis in Engine Cooling.

Engine Mechanical
    • Excessive oil in the combustion chamber. This condition can be caused by leaking valve seals. Refer to Oil Consumption Diagnosis in Engine Mechanical 2.2 L (L61).
    • High cylinder compression--Refer to Engine Compression Test in Engine Mechanical 2.2 L (L61).
    • Excessive carbon buildup--Check the combustion chambers. Clean the chambers with Top engine cleaner. Follow the instructions on the can.
    • Incorrect basic engine parts. Inspect the following:
       - The camshafts
       - The cylinder head
       - The pistons
       - Other components, as applicable.

Additional Checks
    • Check for proper operation of the manifold absolute pressure (MAP) sensor. Ensure that the MAP sensor is not out of range.
    • Check the park/neutral position (PNP) switch input with the vehicle in drive, and with the gear selector in drive or in overdrive.
    • Check the torque converter clutch (TCC) operation. Applying the TCC too soon can cause the engine to spark knock. Refer to Road Test in Automatic Transmission 4T40-E/4T45-E.
    • If the scan tool readings are normal, and if there are no engine mechanical malfunctions, fill the fuel tank with a known quality gasoline that has a minimum octane reading of 87. Re-evaluate the vehicle performance.