GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 Park Avenue 🢒 Engine 🢒 Engine Electrical 🢒 Detonation/Spark Knock

Detonation/Spark Knock

Checks

Action

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

Preliminary Checks
    • Refer to Symptoms - Engine Controls Important Preliminary Checks Before Starting.
    • Refer to Symptoms - Engine Controls Visual/Physical Checks
    • Search for 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 items that can cause an engine to run lean (Long Term FT 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 Maintenance Items in Maintenance and Lubrication.

Engine Cooling System

Check for obvious overheating problems:

    • Low engine coolant
    • Restricted air flow to radiator, or restricted water flow through radiator.
    • Inoperative electric cooling fan circuits. Refer to Symptoms - Engine Cooling .
    •  Correct coolant solution should be a 50/50 mix of GM 1052753 or equivalent antifreeze coolant and water. Refer to Cooling System Draining and Filling in Engine Cooling.

Engine Mechanical
    • Excessive oil in combustion chamber--Leaking valve seals. Refer to Valve Stem Oil Seal and Valve Spring Replacement in Engine Mechanical.
    • Low cylinder compression. Refer to Engine Compression Test in Engine Mechanical.
    • Combustion chambers for excessive carbon buildup. Clean using top engine cleaner. Follow instructions on the can.
    • For incorrect basic engine parts. Inspect the following:
       - Camshaft
       - Cylinder heads
       - Pistons, etc.

Refer to Engine Compression Test in Engine Mechanical.

Additional Checks
    • Check for proper exhaust gas recirculation (EGR) system operation. Refer to DTC P0401 .
    • Check the transaxle range switch input with the vehicle in drive and the gear selector in drive or overdrive.
    • Check torque converter clutch (TCC) operation. TCC applying too soon can cause the engine to spark knock. Refer to Diagnostic Starting Point - Automatic Transmission in Automatic Transaxle.
    • If scan tool readings are normal and there are no engine mechanical faults, fill the fuel tank with a known quality gasoline that has a minimum octane reading of 87, for VIN K, 91 for VIN 1 and re-evaluate vehicle performance.