What are the causes of timing chain noise?
2 Answers
The causes of timing chain noise are as follows: 1. Tensioner failure causing the timing belt or timing chain to vibrate and produce impact noise; 2. Tensioner pulley bearing noise; 3. Over-tightened tensioner, resulting in timing belt or timing chain noise; 4. Timing chain wear or timing belt wear (backside) causing noise. The characteristics of timing belt noise are: 1. When the engine is running at low speed, there is a sound similar to valve tapping in the upper front part of the engine, which weakens or becomes irregular as the speed increases; 2. After adjusting the valve clearance, the noise still persists, and when touching the timing gear cover, a vibration can be felt with the fingers.
As someone who frequently works on car repairs, I've seen timing chain noises mostly caused by chain wear or stretching. Over time, loose chain links can produce a ticking sound, and tensioners often have issues too, like hydraulic pistons sticking or failing. Insufficient oil lubrication is another major cause – wrong viscosity or not changing old oil worsens chain friction. I've also encountered cases where sprocket wear leads to poor engagement, creating sharper noises. If ignored, the chain might skip teeth, potentially causing engine damage with repair costs running into tens of thousands. I recommend early inspection and replacing the chain/tensioner when necessary.
