The purpose of a timing belt, timing chain or timing gears is to keep the valves synchronized with the pistons. The intake valves open to let the air-fuel mixture into the cylinder, the valves are closed during the compression and power strokes and the exhaust valves are open during the exhaust stroke.

In winter, that grayish, gooey substance that sticks to your vehicle during cold weather is some form of magnesium chloride and should be washed from your vehicle, including the undercarriage, to prevent corrosion of electrical wires, nuts, brake shoes and even ball joints.