Look for leaks, cracks, rotted rubber. Replace faulty clamps. Inspect all engine belts for wear and cracks. Replace if worn, cracked or glazed. Adjust loose belts.
Usual life is about four years.
If a temperature gauge shows the engine is running too hot or cool the thermostat may be jammed and should be replaced. Your car or truck is likely to have at least six important filters which work to prevent damage from occurring to your vehicle's engine and other parts. It's important to have these filters checked and changed or cleaned on a regular basis. Change after 10,000 miles. Replace after 24,000 miles.