Is It Necessary to Repair Loud Valve Noise?
2 Answers
Whether to repair engine valve noise depends on the specific situation. If the valve noise is caused by excessive valve clearance, severe wear of the camshaft or valve tappet, it needs to be repaired at an auto repair shop. If it is due to excessive oil viscosity or insufficient oil volume, simply changing to a lower viscosity engine oil will suffice. Causes of Engine Valve Noise: The main cause of engine valve noise is excessive valve clearance, especially after the owner performs an engine cleaning, this situation is more likely to occur. Other causes include severe wear of the camshaft or valve tappet, causing the tappet to jump and strike the valve during operation, as well as excessive oil viscosity and insufficient oil volume. Pulley Bearing Noise: If there is simply pulley bearing noise inside the engine, just tightening the belt and applying some lubricating oil can help. If the pulley shaft or generator bearing is damaged, the belt can be removed, and each shaft can be rotated one by one. The one that makes noise is the problematic one, and tightening it can solve this type of issue.
I remember encountering this ticking sound last time when driving my cousin's Passat. The mechanic said there are two types of valve noise: if it's a light ticking that disappears when the engine warms up, it's probably normal hydraulic lifter operation; but if it's a loud metallic knocking that persists whether the engine is cold or hot, it's most likely excessive valve clearance. This MUST be repaired! A bent valve stem can damage the piston, and the cost of engine repair could be half the car's value. I've personally seen cases where people delayed repairs until a broken valve spring punched a hole through the cylinder head - the towing fee alone cost three times more than the valve repair would have.
