What causes the clicking sound when starting a car after it has been parked for several days?
1 Answers
Because of ignition delay, unburned gasoline is just discharged into the exhaust pipe when the spark plug ignites, and the sound is produced when the atomized gasoline is ignited in the exhaust pipe. This is mainly due to the vehicle being parked for too long, causing the battery to drain. Starting the car after 7 or 8 attempts is considered a good situation. Generally, if the vehicle remains unused for an extended period, it is best to charge the battery every three days and let the engine idle for about 10 minutes. If the car has aftermarket navigation systems or similar large electrical accessories, the power consumption will be even more severe. Below is additional information: 1. The abnormal sound only occurs during idling or low-speed operation. Possible causes include: excessive clearance between the piston and cylinder wall; overly tight piston pin or connecting rod bearing assembly; excessive clearance between the tappet and its guide hole; wear on the camshaft profile; sometimes, a loose starter pulley causing noise (more noticeable during speed changes). 2. When maintaining a certain speed, the sound becomes chaotic, and brief noises occur during rapid deceleration. Possible causes include: cracked camshaft timing gear or loose fixing nut; broken crankshaft; loose piston pin bushing; excessive axial clearance of the camshaft or loose bushing. 3. The abnormal sound appears during rapid acceleration and persists during high-speed operation. Possible causes include: loose connecting rod bearing, melted or mismatched bearing shell; loose crankshaft bearing or melted bearing shell; broken piston pin; broken crankshaft.
