What Causes Abnormal Noises When Starting the Car?

[Arthur]

The causes of abnormal noises include excessive engine valve clearance and transmission shaft support failure. Below are detailed explanations and solutions: 1. Excessive engine valve clearance: When the vehicle has been driven for many kilometers or used for a long time, the engine valves and hydraulic lifters will experience some wear. Excessive clearance will lead to abnormal noises. Solution: Disassemble the cylinder head to replace the components and change the engine oil regularly. Otherwise, the lubrication effect of the oil will deteriorate, accelerating the wear of the valves and hydraulic lifters. 2. Transmission shaft support failure: This is caused by wear of the intermediate bearing, poor lubrication, or improper assembly leading to bearing damage. Solution: After parking, manually push and pull the transmission shaft near the intermediate bearing support. If there is significant looseness, it should be removed for repair. If the oil seal or rubber components are damaged, they should be replaced. If the bearing is not loose, lift the rear wheels and manually twist the transmission shaft to check.