Understanding Your Volvo Timing Belt
To understand the purpose of your Volvo timing belt, you'll need to know the basics of how a gas-powered engine functions.
A set of valves let fuel and air into the engine's cylinders and then expel exhaust gasses once combustion has occurred, all with split-second timing. Rotating camshafts control the valves, but what controls the camshafts? Below the camshafts, a crankshaft is rotated by the motion of your engine's pistons (driven by said combustion process), and this crankshaft rotation controls the camshafts via your timing belt.
Your engine starter gets this dance going, and your timing belt is what keeps the camshaft and crankshaft perfectly in sync.
This synchronization is how a gas engine can perform so many precise tasks per second, but the continuous motion degrades your Volvo timing belt over time. A dangerously worn-down timing belt can present serious issues; getting it inspected and serviced on time is critical to a long and healthy vehicle life.