Can Jetta valve be adjusted?

The old Jetta valve cannot be adjusted. Excessive wear of valve parts leads to abnormal engine noise; Wear and damage of the valve guide will cause engine oil combustion and abnormal sound of the valve, which will lead to the damage of the whole valve mechanism in serious cases. The solution to abnormal valve sound is as follows: 1. It is caused by the gap between hydraulic valve tappet and cam (or valve seat). In most cases, the clearance is caused by excessive wear of the hydraulic tappet, and the abnormal sound is caused by the rapid release of oil pressure inside the tappet, so it is necessary to replace the hydraulic tappet. 2. Check the engine oil level for abnormal noise caused by too high or too low crankcase oil level. The abnormal sound caused by dirty tappets needs to be cleaned up; 3. Abnormal sound caused by valve guide wear. It is necessary to wrap the valve guide and install the valve with a rough valve stem. Abnormal sound caused by too thin engine oil needs to be replaced with engine oil with appropriate viscosity; 4. Abnormal sound caused by low oil pressure needs to be checked.