Slight whine noise from upper timing belt cover

[jelloslug]

I'm getting a slight whine from the upper timing belt area when the engine is reving down. The belt seems tight when you look through the lower inspection window. The belt has around 12k miles on it. Is this a sign that it may be too tight or too loose?

 

[NotSoSlowSHO]

Are you sure that it is from the timing belt?

Id suspect an idle pulley bearing or something similar first.

 

[jelloslug]

Are you sure that it is from the timing belt?

Id suspect an idle pulley bearing or something similar first.

It's definitely from the timing belt. It's a "toothed belt on a cog" kind of whine (kinda like a big blower just not so loud). Also, I just replaced both of the accessory belt tensioners with new ones.

 

[wood_e]

I assume that the noise increases with engine speed, correct?

 

[jelloslug]

Actually the noise is only there when the engine is reving back down.

 

[sdpatt]

To check and reset the tension on the belt with the timing belt covers installed, you can take off the small door from the lower timing belt cover, loosen the 14mm nut about 1/2 turn, rotate the crankshaft at least two full turns in the clockwise direction only until the first, yellow mark (60 degrees before top dead center on the number 1 cylinder) aligns with the "0" degree index mark on the lower timing belt cover (this causes the greatest slack on the tensioner side of the timing belt), retighten the 14mm nut 25-37 lb-ft and reinstall the door.

 

[SHO#7]

Are you able to remove the upper timing belt cover to take a look? Is it possible that the timing belt has a slight vibration between the two cam gears, and it is causing your noise. I really should not respond to difficult threads like this, but just thinking out loud.