What is valve clearance?
2 Answers
Valve clearance refers to the gap between the valve and its transmission components when the engine is in a cooled state and the valve is closed. Below is an extended introduction: 1. When the valve clearance is too large: The intake and exhaust valves will open late, resulting in insufficient air intake and incomplete exhaust, leading to a decrease in power. It also increases the impact on the valve train components, accelerating wear and increasing noise. 2. When the valve clearance is too small: As the engine operates and the temperature rises, component expansion can cause gas leakage, naturally reducing power. Over time, carbon deposits may form on the sealing surfaces, and in severe cases, the valves may collide with the pistons.
I remember the first time I heard about valve clearance, it sounded quite mysterious to me. Simply put, valve clearance refers to that small gap between the valve stem and the rocker arm in the engine, left to allow room for parts to expand under high temperatures. If you've ever taken apart an engine, you'd see it – failing to adjust it properly can lead to big trouble. Back when I was young, I learned this the hard way with that beat-up van I drove. I didn't check the clearance regularly, and when the engine got hot, the valves wouldn't close properly. As a result, the car lost power, felt sluggish when I stepped on the gas, and made weird rattling noises. Later, when I took it to the shop, they found the clearance was too small, and thermal expansion had completely jammed it. From then on, I understood how crucial this thing is – it's not just about leaving a gap. If it's designed too tight, it can burn out the valves; too loose, and it increases wear and noise. My advice is to check it every 20,000 kilometers, and measure it accurately when the engine is cold to avoid small issues turning into expensive repairs.
