Sounds like the bearing in the Idler Pulley is bad

[robfg67]

I recently had to replace my overflow bottle and during the cooling system repair process (replaced tired hoses & flushed system) the serpentine belt got wet (with antifreeze).

 

It's been about 3 days (about 50 miles total) driving and I have a metal knocking noise at all speeds that sounds similar to the bearing in the idler pulley going bad. I didn't touch the belt adjustment at all. Also, I have NO belt squeal at either.

 

Do I just need to give the belt more time to "dry-out" or could I have another problem? Thanks

[Eagle]

The idler pulley bearing doesn't "knock" when it goes bad. It "howls" or "shrieks."

 

Very loudly.

[kyleag89]

Water pump bearing went bad when it overheated.. :wavey:

[robfg67]

Well, on the drive home tonight, it began howling & shrieking very loudly. I guess I know what my next project is.

[Oizarod115]

easy enough to check, just zip the belt off and spin all the pulleys.

 

if they all seem smooth fire it up with the belt off and see if the noise is still there, (don't run it very long, just enough to verify the engine is quiet. 30 seconds should be long enough)