What Causes the Engine Belt to Squeak?
3 Answers
The reasons for engine belt squeaking: It is caused by belt wear and aging, and timely replacement is necessary. Consequences of engine timing belt breakage: It will cause the engine to fail to operate normally, seriously affecting the engine's working condition, and may damage the valves, pistons, and cylinder walls. When cracks and aging appear on the engine timing belt, it should be replaced promptly. Below are the steps for replacing the timing belt: 1. Secure the crankshaft: Remove the valve cover, dismantle the crankshaft pulley, and take off the timing chain cover; rotate the crankshaft to align the first cylinder to top dead center, then tighten the crankshaft fixing screw to secure the crankshaft; 2. Align the camshaft grooves: Rotate the intake and exhaust camshafts; there are grooves at the rear of the camshafts, align the grooves of both camshafts horizontally and insert the special tool; 3. Install the timing chain: Remove the old chain and install the new one. The crankshaft pulley does not have a keyway; during installation, align the round hole on the pulley with the groove on the chain cover; 4. Adjust the sensor position: The crankshaft position sensor is adjustable; ensure there is no gap during installation, otherwise, it may trigger a fault code; the crankshaft sprocket and pulley can rotate freely.
I've been driving for over twenty years and have encountered the issue of squeaky belts quite a few times. Usually, it's because the belt is loose or the rubber has aged and cracked. When a belt has been used for a long time, insufficient tension can cause it to slip and make noise, especially noticeable during cold starts. Once, my car squealed when I started it in the morning. I got out to check and found the belt surface dirty and covered with oil—cleaning it fixed the problem. If the belt is tight but still squeaks, there might be an issue with the driven components, like a faulty alternator bearing that's struggling to turn the belt. Don’t underestimate this noise—it’s a warning that the belt could snap, and losing engine power on the highway is extremely dangerous. I advise friends to have mechanics check belt tension during regular maintenance, using a tension gauge to ensure it’s within the standard range—it’s both convenient and safe. New car belts might occasionally squeak due to improper installation; just take it back to the dealership for an adjustment. In short, don’t ignore squeaky belts—delaying repairs will only increase the cost.
I think the most common causes of belt squeaking are belt looseness or deterioration. I remember when I first bought my car, a friend told me to be wary if the belt starts making noise. Once, while driving in the rain, the belt started squeaking—it turned out to be noise from slipping when wet. Later, I read a car manual and learned that when belts age, the rubber hardens and loses elasticity, causing insufficient tension and noise; contamination like oil or dust buildup can also reduce friction and cause squeaking. If left unrepaired, the belt can wear out faster and potentially snap, leading to issues like the AC light not working or the engine stalling, which would leave you stranded and needing a costly tow. I suggest novice car owners start with the basics: idle the engine for a few minutes to locate the noise source, gently press the middle of the belt to check for excessive looseness—if it's too slack, tighten it or replace it. If unsure, visit a repair shop for a professional diagnosis—it's a small expense for peace of mind on the road.
