How it works: The tensioner is usually a spring-loaded mechanism that keeps the belt taut. As the belt wears or the engine components experience thermal expansion and contraction, the tensioner automatically compensates.
If you're experiencing problems: Instead of trying to adjust the tensioner itself, consider these possibilities:
* Worn belt: The most common reason for belt slippage is a worn or glazed belt. Replace the belt.
* Worn or damaged tensioner: If the tensioner pulley is seized, damaged, or the spring is broken, it needs to be replaced. This is common as they're wear items.
* Misaligned pulleys: Check to make sure all the pulleys are properly aligned. A misalignment can cause premature belt wear and slippage.
* Incorrect belt routing: Ensure the belt is routed correctly around all the pulleys. The routing diagram is usually found on the underside of the hood or in your owner's manual.
In short: Don't try to adjust the tension on a self-adjusting tensioner. If you're having issues with the serpentine belt, focus on identifying and replacing the worn or faulty component. If you're not comfortable performing this type of repair, take your vehicle to a qualified mechanic.
