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Belt Noise

973 Views 7 Replies 4 Participants Last post by  Terrasmak
Hi - My 2011 Sienna 3.5L FWD is starting to make a chirping noise from the belt area. It's probably from one of the pulleys; problem is identifying which one. Any tips on how to find the issue, or anyone have the same issue?

Here's a link to the audio of the noise. Sienna-Noise.mp3
Thanks for the help.
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My first thought was water pump, but that didn't sound like my water pump when the bearings went out on that. I didn't get chirping, but like knocking sound. I could see the pulley wiggling slightly side-to-side.

Try watching the pulleys with a flashlight, see if any wiggle as the engine runs.

With the engine off, try grabbing the pulleys and wiggling them. The belt tension makes this difficult, so you can remove the drive belt first. See this post on my water pump replacement thread for removing the drive belt. In short, jack the front of the car up, support on jackstands. Take off the front passenger tire, then the plastic panel behind the tire. Use a 14 mm wrench on the tensioner pulley to loosen the belt, and jam a 5 mm allen key into the pulley to hold it with no tension. The belt will now slip right off.

With the belt off, you have access to all the pulleys. Grab them and try to wiggle them. If they wiggle, or if you spin them and they are rough, and don't spin smoothly, the bearing is bad.

The water pump pulley should spin smoothly but will have a lot of friction, so it won't keep spinning after you let go. The idler and tensioner pulleys should spin freely and continue spinning for a bit after you give them a quick spin. The AC pulley may have a tad of friction from the clutch but should still spin smoothly. None should be able to wiggle, at least not more than a hint.

It may also be the belt slipping just a little? Check the condition of the belt when you remove it. If there are any cracks or it just appears old and dry, replace ti.
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Just ordered a Gates belt to replace the existing belt. Figured it was worth the $25 since I have to re-install it anyway after checking the pulleys. Biggest concern is having to replace the tensioner as it seems fairly complicated and the part itself is pricey.

Thanks for the detailed instructions. Extremely helpful, especially regarding the pulleys. I'll let you know what I find.
Yes, I hope it’s not the tensioner too. When I was doing my water pump I looked at that and it seemed it couldn’t be unbolted without removing the AC compressor. Hopefully I’m wrong about that, I haven’t looked into replacing it.

However if it’s just the tensioner pulley bearings, I couldn’t find a Toyota tensioner pulley sold separately, but you should be able to find an aftermarket pulley or if you’re cool with doing your own bearings you can press out the old bearings and press in new bearings really easily.
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