How do I stop my serpentine belt from squealing?

To stop a serpentine belt from squealing, check the belt for wear, and replace it if it is damaged. If the damage is minimal, spray the inside of the belt with belt dressing while the engine is running.

1. Check the belt for wear

   Inspect the appearance of the belt, and look for signs of severe tearing. Insert the narrow end of a belt wear tool between the grooves of the belt. Replace the belt if the tool is flush with or below the grooves.

2. Obtain an assembly diagram for the serpentine belt

   Locate the assembly diagram for the serpentine belt underneath the hood. If your vehicle does not have one, look for it in your repair manual or draw one by hand.

3. Remove all necessary parts

   Determine which parts need to be removed to gain access to the serpentine belt, and remove them.

4. Remove part of the belt

   Place the serpentine belt removal tool on the tensioner bolt. Rotate the bolt slightly, and remove the parts of the belt that rest on smooth pulleys.

5. Remove the rest of the belt

   Turn the bolt again, and remove the rest of the belt.

6. Install the new belt

   Use your diagram to install the new belt loosely, and turn the tensioner bolt simultaneously.

7. Secure the new belt

   Tighten the belt around the crankshaft pulley, followed by the grooved pulleys and ending with the smooth pulleys. Tighten the tensioner to the recommended spec.

8. Put the engine back together

   Return all removed parts.