The tensioner belt on a Toyota RAV4 is located in the centre of the engine and is used to keep the serpentine belt tight. A faulty tensioner pulley will not allow the belt to stay tight around the pulleys. Replacing the tensioner takes only a few minutes.
Park the RAV4 on a flat and level surface. Take the keys out of the ignition to prevent accidental starting. Open the bonnet to access the engine compartment. Locate the tensioner pulley in the middle of the front of the engine.
Place a socket wrench on the bolt to the right of the tensioner pulley and push down to relieve the tension off of the belt. Slide the belt off the pulley.
Unbolt the two bolts holding the tensioner in place with a socket wrench. There will be a bolt on the top and one to the left.
Pull the tensioner off of the engine and replace it with the new one. Secure the tensioner to the pulley with a socket wrench.
Lower the tensioner with a socket wrench to slide the belt over the pulley. Pull the bolt back up to tighten the belt.
Start the SUV and allow it to idle long enough to inspect the belt. Ensure that the belt has no sag as it rides along the pulley.
Close the bonnet and turn off the engine.
A tensioner pulley can be purchased at any Toyota dealership.