What Problems Can Occur with Poor Valve Adjustment?
2 Answers
Excessive valve clearance will result in reduced valve opening, increased intake and exhaust resistance, insufficient intake volume, decreased power performance, and poor exhaust flow. It also increases the impact force of the valve transmission group on the valve assembly, leading to noticeable abnormal noises. Below is an introduction to automobile valve adjustment and related information: Cylinder-by-Cylinder Adjustment Method: Based on the cylinder firing order, after determining that a piston is at the top dead center of the compression stroke, the intake and exhaust valve clearances of that cylinder can be adjusted. Once adjusted, rotate the crankshaft and follow the same method to adjust the valve clearances of the other cylinders step by step. Composition of the Valve: A valve consists of a valve head and a stem. The valve head operates at very high temperatures (intake valve: 570~670K, exhaust valve: 1050~1200K) and is subjected to gas pressure, valve spring force, and the inertial force of transmission components. Due to poor lubrication and cooling conditions, the valve must possess sufficient strength, stiffness, heat resistance, and wear resistance. Intake valves are typically made of alloy steel (chromium steel, nickel-chromium steel), while exhaust valves are made of heat-resistant alloys (silicon-chromium steel). The valve stem is cylindrical and continuously reciprocates within the valve guide, requiring its surface to undergo heat treatment and polishing. The shape of the valve stem end depends on the fixing method of the valve spring. A common structure uses two half-lock pieces to secure the spring seat, with the valve stem end featuring a groove to install the lock pieces.
Hey, if the valve adjustment isn't done properly, there can be a lot of problems. The most common issue is increased engine noise, with constant ticking sounds that can be really annoying. The power output also suffers; the throttle feels weak, making it difficult to climb hills or overtake. Fuel consumption can skyrocket, wasting gasoline and your hard-earned money. Emissions also worsen, with black smoke from the exhaust polluting the environment. In more severe cases, if the valve clearance is too small, it can cause sticking or burning, while if it's too large, it leads to power loss and accelerates engine wear. I've seen some cars struggle to start or shake violently at idle as if they're falling apart. It's recommended that owners regularly check the valve clearance, keeping it at 0.25-0.35mm for older cars. A professional adjustment can prevent all these troubles. Don't wait until the problem becomes severe before fixing it.
