Knocking in the Engine When Accelerating
Knocking in the engine when accelerating is a worrying symptom that indicates problems with the engine mounting or internal components. Ignoring this sign can lead to serious damage and an emergency situation on the road.
Likely causes — most common first
Wear of Engine Mounts
The rubber or hydraulic elements that hold the engine in place deteriorate over time. When accelerating sharply, the engine tilts and hits the body or other parts due to weakened mounts.
Fuel Detonation in Cylinders
Fuel ignites too quickly and unevenly due to low-quality petrol or ignition problems. This creates shockwaves inside the engine, which sound like a metallic knock or clang under load.
Wear of the CV Joint
The constant velocity joint transmits power from the gearbox to the wheels. When the inner or outer CV joint wears out, a characteristic crunch or metallic knock occurs during acceleration.
Problems with Connecting Rod Bearings
Due to oil starvation or high mileage, the bearings of the crankshaft wear out. This is the most dangerous cause, when engine parts knock against each other under load.
