If your vehicle is showing engine pings, knocks, or rattles under heavy acceleration, here are the most likely causes and the parts you'll need to fix each one.
Spark plugs that are severely worn or have the incorrect heat range can create hot spots in the combustion chamber. Installing plugs with a heat range that is too hot for the engine is a common installation error that leads directly to pre-ignition and pinging under load.
The knock sensor's job is to listen for the early signs of pinging and tell the engine computer to adjust the ignition timing to prevent it. If the sensor fails, the engine cannot protect itself from detonation during heavy acceleration.
The Exhaust Gas Recirculation (EGR) valve introduces a small amount of exhaust gas back into the engine to lower combustion temperatures. If the valve is clogged with carbon or fails to open, cylinder temperatures spike under load, causing the fuel to detonate prematurely.
If the engine receives too much air or not enough fuel, the mixture burns too hot and fast, causing a rattle or ping. This is frequently caused by unmetered air entering through a vacuum leak or a dirty mass air flow sensor miscalculating the incoming air.
An engine that is running hotter than its normal operating temperature will naturally cause the air/fuel mixture to ignite too early. A sticking thermostat or low coolant levels can raise the internal engine temperature enough to cause severe pinging.
On older vehicles with mechanically adjustable timing, setting the distributor too far advanced during a tune-up will cause the spark plugs to fire too early in the compression stroke, resulting in heavy knocking under acceleration.