Is Loud Valve Noise Related to Engine Oil?

[LeStella]

Loud valve noise in a car is related to engine oil, and the reasons are: 1. Insufficient engine oil: When the oil level drops to a certain extent, air enters the hydraulic lifters through the oil passages, creating gaps that cause valve noise; 2. Air entering the oil passages during oil change: When draining the oil, the oil in the passages is emptied, and air enters. When starting the engine, air may enter the hydraulic lifters, causing valve noise; 3. During engine operation, oil circulates in the hydraulic lifters. If sludge forms in the engine, it can clog the oil passages, causing the hydraulic lifters' automatic gap adjustment function to fail, resulting in valve noise; 4. If the engine is severely worn, using oil with low viscosity can also cause valve noise.