Valve Noise Repair?
2 Answers
Valve noise should first identify the cause of the noise, then address it accordingly. Common repair methods include checking the spring tension of the valve and readjusting the valve clearance. If the lock nut on the screw is loose, it should be tightened, and severely worn parts should be replaced. For valve leakage: Remove the cylinder head, grind the valve, check the elasticity of the valve spring, and readjust the valve clearance. For valve knocking: Readjust the valve clearance. If the lock nut on the adjustment screw is loose, tighten it and replace any severely worn parts.
I'm quite familiar with valve noise issues, and the key is identifying the type of sound. The most common valve noise is a ticking sound, usually caused by excessive valve clearance. There are two scenarios: older vehicles require manual valve clearance adjustment - you'll need to remove the valve cover and use a feeler gauge for measurement and adjustment. Modern vehicles mostly use hydraulic lifters for automatic adjustment, and if these fail, the entire valve assembly needs replacement. This isn't cheap - parts alone can cost over a thousand, with labor being the major expense as it requires removing the engine's top cover. If the noise fluctuates, it might be caused by insufficient oil supply, in which case you should first check the oil pump and oil passages - this is much more affordable, as simply changing the oil or cleaning the oil passages might solve it. A few seconds of noise during cold starts is normal, but persistent ticking when the engine's warm shouldn't be ignored, as it could damage the camshaft and lead to costly engine overhaul.
