How to Change a Toyota 1999 Sienna's Timing Belt

The 1999 Toyota Sienna 3.0-liter engine is a freewheeling engine, which means that if the timing belt stretches past its useful life, chances are, it won't cause any damage to the pistons and valves. The manufacturer recommends changing the timing belt every 90,000 miles or 72 months, whichever comes first. The procedure uses a special tool that is available from a Toyota dealer.

Difficulty:

Challenging

Instructions

things you'll need:

• Set of wrenches
• Floor jack
• Jack stands
• Set of sockets
• Lug wrench
• Ratchet
• Special tool Toyota part number 099231-54015
• Special tool Toyota part number 09330-00021
• Vise or press
• Allen wrench
• Torque wrench

1. • 1

     Disconnect the negative battery cable and set it aside, but do not allow it to touch metal. Raise the front of the Sienna using the floor jack. Support the car on jack stands. Remove the coolant reservoir using the appropriate socket. Remove the right front wheel using the lug wrench. Remove the right fender apron seal using the appropriate socket.

   • 2

     Move the accessory drive belt tensioner using a ratchet to release tension on the accessory drive belt. Support the engine with the floor jack. Remove the right engine mount and control rod using the appropriate sockets. Remove the alternator bracket using the appropriate socket.

   • 3

     Remove the crankshaft bolt using the appropriate socket. Remove the crankshaft pulley using special tools 09213-54015 and 09330-00021. Remove the timing belt covers using the appropriate socket. Remove the engine mount bracket and the guide washer.

   • 4

     Install the crankshaft bolt. Use the bolt to turn the crankshaft until the timing marks are lined up. There are three timing marks: The mark on the crankshaft is at 12 o'clock and is a dot. The marks for the camshafts are at the 12 o'clock position on the heads, and are dots. The camshaft sprockets and the crankshaft sprockets all have dots. The dots must line up.

   • 5

     Unbolt and remove the auto tensioner and the dust boot using the appropriate wrench.

   • 6

     Work the tensioner and the idler pulley to make sure they turn smoothly. If they look worn, make noise or seem to hang up, replace them. Check the auto tensioner for oil leaks. If oil is leaking, replace it with a new one. If the auto tensioner pushrod moves when you push it against a hard surface, it does not have enough strength--replace the auto tensioner. If the pushrod protrudes more than 0.39 to 0.43 inches, replace the tensioner.

   • 7

     Check the timing marks to ensure they are still lined up. Install the timing belt by routing it around the pulleys, starting on the crankshaft pulley and working your way counterclockwise around the water pump pulley, over the right camshaft (as you are facing the engine), under the idler pulley, over the top of the left camshaft and behind the tensioner pulley. As you route the belt, keep tension on the right side (water pump side) and line the marks on the belt to the marks on the sprockets. The marks on the belt are small dots on the front of the belt.

   • 8

     Push the pushrod in the tensioner in, using the press or vise. Slide an Allen wrench through the holes in the body of the tensioner and into the pushrod (as you push the pushrod in, the holes will line up, allowing you to put the Allen wrench in). The Allen wrench holds the pushrod in position.

   • 9

     Install the tensioner and the dust boot in the reverse order of removal. Tighten the tensioner bolts to 20 foot pounds of torque. Remove the Allen wrench. The tensioner will apply tension to the timing belt. Turn the crankshaft clockwise two turns (slowly). Line up the timing marks at the end of the second turn.

   • 10

     Remove the crankshaft bolt. Install the rest of the parts in the reverse order of removal. Reinstall the crankshaft bolt and tighten it to 159 foot pounds of torque.

Tips & Warnings

• Remove the spark plugs to make turning the engine over by hand easier. Number the spark plug wires so you remember where they go.

• Do not turn the crankshaft or the camshaft while the belt is off.