Toyota Sienna (2006) makes noise on startup

Lately my Sienna makes this noise whenever it is started. The noise lasts for 5-10 seconds. It builds up very loud towards the end and then stops abruptly. I made a recording of the sound and have attached it.

Attached is the recording of the noise.

Are the serpentine belts original? My wife’s 06 Sienna belts would screech at start up if the AC was left on. I had both belts replaced when the timing belt/water pump/tensioner was replaced recently. The afternoon after I picked it up there appeared to be a metal on metal screeching noise for a few minutes after start up. The power steering belt needed to be tightened (no tensioner pulley). Note, I’ve heard similar sounds on my other vehicles prior to changing their serpentine belts.

Note if the timing belt has not been replaced it is at least a year overdue (7yr/90k whichever comes first).


Classic sound of a bad serpentine belt. Have a new one installed and it should clear up the problem.

You could also test it this way.
Have someone else start the car, while you stand at the ready with a spray bottle of water. Have the sprayer set on strean…not mist…and keep clear of moving parts.
As soon as it starts, spray the belt with a little water. The weater will lubricate the belt momentarily and the sound will stop abruptly.


After 8 years and God-only-knows how many miles, either the serpentine belt is glazed/cracked/stretched or the belt’s tensioner is worn out. Start out by replacing the serpentine belt, and if that doesn’t cure the problem, then the tensioner will need to be replaced.

Thanks for the input everyone. I haven’t had the timing belt replaced yet. The van has about 90K miles on it.

@Yosemite‌, I will try out the water spray to make sure it is the belt. Thanks again.

That sounds to me like a serpentine belt that’s contaminated with engine coolant or has simply become worn and stretched to the point that the idler isn’t able to maintain the needed tension. Examine the belt, and if it’s definitely OK then take a long, hard look at your water pump. It also could be a failing idler pulley bearing on either the timing or the serpentine belt as well, though, so those merit a hard look. By the way, according to the Gates database, the 3.3L in the '06 Sienna is not an interference engine, so there’s no need to panic if the timing belt idler is the squeaker. This DOES NOT mean you can ignore it and wait for it to fail before replacing it, because the failure could happen at a very dangerous time - like crossing a railroad track with a train visible in the distance.

Thanks everyone for the prompt and helpful response. I did have the serpentine belt changed and the noise is gone :). Thanks again.