What Causes Valve Noise?

[LeCamille]

Valve noise is caused by: 1. Gap formation or severe wear in hydraulic lifters; 2. Too high or too low oil level in the crankcase; 3. Dirty lifters; 4. Worn valve spring seats with grooves, and wear between valve stems and guides; 5. Oil being too thin—replace with oil of appropriate viscosity; 6. Oil pressure being too low or too high. The methods to address valve noise are: 1. Remove the cylinder head; 2. Grind the valves, check the spring tension of the valve springs, and readjust the valve clearance. The function of valves is to specifically input air into the engine and expel exhaust gases after combustion. Based on engine structure, they are divided into: intake valves and exhaust valves.

[KadenDella]

Last time when I got my car repaired, the mechanic mentioned that valve noise is most commonly caused by improperly adjusted valve clearance. New cars are fine when they leave the factory, but after tens of thousands of kilometers, as metal parts wear out, that 'ticking' sound starts to appear. Additionally, many cars nowadays use hydraulic lifters, which are particularly delicate. If the oil quality is poor or the oil isn't changed regularly, sludge can clog the lifter oil passages, causing noise during operation. Also, if the valve stem and guide wear excessively and become loose, the knocking sound can resemble tapping on a wooden fish. The most troublesome issue is a broken valve spring, which produces a particularly sharp sound. If you encounter such metal knocking sounds, it's crucial to get it checked as soon as possible—the engine is the heart of the car.

[LeKinsley]

I've been into car modifications for over a decade and have seen plenty of valve noise issues. Most problems occur in the upper part of the engine, especially with tappets and valve clearance. On older cars, camshaft wear leading to increased clearance is the most common cause – it sounds like a mechanical watch with a loose spring ticking away. Modern cars mostly use hydraulic lifters, but they're very particular about oil quality. If the oil is subpar or overdue for a change, the lifters can stick and make noise. Also, when valve springs fatigue and break, or rocker arms wear severely, you'll hear a distinct 'clack-clack-clack' noise at higher RPMs. I remember one time when my oil level was too low, causing abnormal hydraulic lifter operation – the noise was terrifyingly loud. In such cases, never delay – immediate inspection and repair is absolutely necessary.

[DeAubrey]

My vintage car has been making a ticking noise during cold starts recently. The mechanic said it's a valve issue. He explained that after a new car runs 70,000-80,000 kilometers, the valve springs gradually fatigue and lose tension, preventing the valves from closing tightly, which causes knocking sounds during operation. Another possibility is improper valve clearance adjustment - when the shims wear out and the gap increases, the valves won't seat smoothly. The mechanic also advised me to check the engine oil, saying inferior oil could jam the hydraulic lifters, causing delayed valve action and abnormal noises. The most dangerous scenario is bent valve stems, which in severe cases could damage the pistons. Now I change to full synthetic oil regularly and have the valve clearance checked every 20,000 kilometers.

[MaxLynn]

From my personal experience in car maintenance, valve noise is mostly caused by three major issues: First, excessive valve clearance, especially in OHC structures where the cam directly drives the valves. When the clearance exceeds 0.3mm due to wear, it produces a ticking sound. Second, faulty hydraulic lifters, which rely on engine oil for lubrication—any instability in oil pressure or presence of impurities can cause them to fail immediately. Third, aging of valve-related components, such as worn valve stems reducing guide precision, resulting in clattering noises during operation. Once, I used engine oil with excessively high viscosity, which had poor low-temperature fluidity, causing lifter starvation and knocking sounds at startup. It's advisable to use the manufacturer-recommended viscosity of full synthetic oil and inspect the valve train every 30,000 kilometers for optimal performance.