The drive belts are located at the front of the engine and are vital for the proper functioning of the vehicle and its parts. They wear out over time and these belts should therefore be inspected periodically and adjusted to prevent major damage to the engine. The number of belts that are required will depend on what accessories are used such as an alternator, power-steering pump, water pump or air conditioning compressor. To inspect for cracks, separation, fraying, or glazing open the hood while checking for defects on the belts. By pushing on a belt halfway between pulleys its tension can be checked. For 4"-7" spaced sheaves there should be 1/4 inch deflection while for 8"-10" spaced sheaves there should be 1/2 inch deflection. Adjustments can be made by tightening or loosening adjustment bolt at alternator, tensioner pulley bolt or through-bolt and adjuster lock bolt for power steering pump belt. The water pump and alternator belt utilize alternator adjuster lock bolt and adjuster bolt respectively. Measure the belt tension after adjustments then repeat if necessary. When replacing one's belts it is recommendable to replace all of them at once instead of buying a single one. While purchasing new ones take with you old ones so as to get correct length, width and design types.When installing a new belt make sure you have returned it in reverse order as before back onto pulleys.The extra measures may need to be taken in case of removal of engines lower splash shield raising vehicle using box end wrench to rotate tensioner in case where we have 2017 later car models with 1.4L engines.Taking off drivebelt,tensioner mounting bolts,reinstalling it back again plus installing new tensioner is what entails a replacement process for any given tensioner.It requires removing drivebelt & tensioner mounting bolts,introducing new tensioner before putting it back on.