Valve Noise Repair?
4 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.
Every time I hear the engine ticking, I have to listen carefully to determine if it's a valve issue. First, confirm whether the sound is coming from the valve cover—open the engine hood and listen closely near the valve cover area. There are three common causes: first, wear on the valve lifters or rocker arms, causing metal-to-metal contact noises; second, a stuck or depressurized hydraulic lifter, which fails to adjust the gap due to insufficient oil supply; third, camshaft surface wear creating pits, leading to a clattering sound when pushing the valves. I recommend checking the simplest causes first: Is the engine oil level sufficient? Is the oil filter clogged? If those aren’t the issue, then consider disassembly for repairs. Additionally, modified cars are particularly prone to this problem because the increased camshaft angle makes the valves move faster, and the stock hydraulic lifters may not handle it. If the engine warning light comes on at the same time, it’s almost certain the cylinder head will need to be removed for servicing.
When it comes to valve noise, if the ticking sound exceeds the normal range, it's time for a check. The main focus is on the valve clearance. For older cars, you can adjust it with a feeler gauge—just bring the engine to operating temperature, shut it off, remove the cover, and adjust the clearance. Most modern cars use hydraulic lifters that self-adjust. If these fail, it's best to replace them as a set; replacing just a few will likely lead to noise returning within days. Actually, valve noise doesn’t always mean you need to tear down the engine. Sometimes, carbon buildup can stick the valve stem, causing poor opening and closing—try adding some fuel system cleaner and running two tanks of gas. A faulty crankshaft position sensor can also be misdiagnosed as valve noise. Repair costs vary widely: adjusting the clearance costs a few hundred, replacing hydraulic lifters around two to three thousand, and if the camshaft is warped, be prepared to spend five to six thousand. Don’t panic if you hear valve noise right after a cold start—if it disappears within a minute or two, it’s fine.
