How to Replace a Toyota Sienna Serpentine Belt

Engine Belt

The Toyota Sienna uses one belt, the serpentine belt (also called the multi-accessory drive belt) to control all engine accessories, including the power steering, air conditioner compressor, water pump and alternator. Located at the front of the crankshaft, the serpentine belt winds around the pulleys connected to the various accessories and ultimately around a tension pulley that keeps the belt at the correct contact tension so that all the engine accessories engage properly.

Changing the serpentine belt on a Toyota Sienna is a fairly simple do-it-yourself project that requires the proper-sized wrench or socket set. Professionals recommend examining the serpentine belt on the Sienna twice per year or every 25,000 miles; look for fraying, cracking and/or missing chunks.

Difficulty:

Moderately Easy

Instructions

things you'll need:

• Replacement serpentine belt
• Wrench set
• Serpentine belt diagram

1. • 1

     Check to ensure the Sienna's engine is cold, then make sure the Sienna is in park, the ignition is in the off position and the key is removed from the ignition to prevent any possibility of the engine engaging during the serpentine belt replacement.

   • 2

     Open the hood and locate the serpentine belt routing diagram sticker on the side of the engine casing. Study it for a moment before removing the existing belt. It is essential the new belt be installed exactly as the diagram indicates.

   • 3

     Find the tensioner pulley, the main pulley that controls the serpentine belt, and fit a 1/2-inch socket wrench over the self-tensioner on the outside of the pulley.

   • 4

     Pull the wrench to the left to move the pulley forward, which loosens the belt, then remove the belt.

   • 5

     Compare the old serpentine belt with the new, replacement belt for length, width and number of grooves on the belt's underside. Be certain the replacement belt is the right part.

   • 6

     Fit the new belt on to each pulley according to the serpentine belt routing diagram on the manufacturer's sticker, or according to the drawing made prior to removing the old belt. Fit the new belt on to the tensioner pulley last, again applying pressure on the pulley's self-tensioner with the half-inch socket wrench to loosen the pulley.

   • 7

     Release the pressure on the self tensioner and allow the tensioner pulley to ease back into place, thereby tightening the new serpentine belt with the appropriate tension.

   • 8

     Remove the wrench and close the hood.

Tips & Warnings

• If the serpentine belt routing diagram on the Sienna is torn, blackened or for any reason unreadable, use a pad and pen/pencil to draw a rough picture of exactly how the existing belt is routed through the various engine accessory pulleys.