What Causes the Clicking Sound from the Chassis After Parking?
1 Answers
The reason for the clicking sound from the chassis after parking is: After prolonged driving, the temperature of the exhaust system becomes very high, especially the three-way catalytic converter, which typically operates at temperatures between 400-800 degrees Celsius. When the car is parked and rapidly cools down, thermal contraction occurs, resulting in a "clicking" sound. The same principle applies to the exhaust pipe, so this is a normal phenomenon. More details are as follows: 1. During a cold start of the car, you may hear a "clicking" noise from the engine compartment. This sound is actually caused by the fuel pump not yet establishing sufficient oil pressure during the cold start, leading to inadequate lubrication of components. Normally, this clicking noise will disappear after the engine runs for a while. 2. There are also some abnormal clicking sounds, such as those caused by aging or loosening engine mounts or an overly rich air-fuel mixture. Engine mounts are rubber blocks placed between the engine and the frame. Their purpose is to reduce vibration and cushion the engine's operation while securing the engine in place. If these mounts become aged or loose, the engine may shake, and in severe cases, a "clicking" noise may occur. This can usually be resolved by replacing the engine mounts. 3. When the engine's air-fuel mixture is too rich, symptoms include difficulty accelerating after starting, uneven engine operation, black smoke from the exhaust pipe, a clicking noise from the engine, and sometimes backfiring. Engine power decreases, and fuel consumption increases. This is often related to carbon buildup or clogged filters and usually does not require major repairs.
