You may just hear your engine stop running if your Audi timing belt breaks. You may hear the unpleasant sound of metal against metal if your Audi timing belt breaks. If you have an Audi timing chain, you may simply experience a gradual deterioration of your car's performance. Regardless of how it goes, one thing's for sure: Without precision timing provided by an intact Audi timing belt or an Audi timing chain that's within specifications, your vehicle is not going to run right, if at all. Since nearly all recent Audi engine designs use overhead camshafts, the Audi timing belt and Audi timing chain need to be fairly long. That also means that the Audi timing belt and Audi timing chain have ample opportunity to whip around and jump a tooth-not a good situation. That's why the tensioner is so important to your valvetrain; if a technician tells you that you need a new Audi timing belt or Audi timing chain, along with a new tensioner, he's not just trying to pay for his new gold pinkie ring. He's trying to save your engine and save you from having to replace the Audi timing belt tensioner or Audi timing chain tensioner a few hundred miles down the road. The same goes for the water pump. Since the water pump on Audi vehicles is often driven by the Audi timing belt or Audi timing chain, replacing the pump while it's accessible is a smart idea in the long run. But no matter what you do along with it, make certain you change your Audi timing belt at the interval specified by Audi. Failure to do so can result in some pretty nasty occurrences, and it's definitely not worth the small cost of an Audi timing belt replacement to put it off.