Chattering sound from engine bay

There is a weird chattering sound coming from my engine bay when I start my truck when it's cold. Once my truck is warm it stops making the sound. I have a 2015 tacoma with 103 k on it

Any ideas ?

 

Chipmunks? Squirrels mating?


Seriously, make a close inspection of the serpentine belt, idlers, tensioner......also all the belt driven components.

 

Maybe it’s the emissions air pump? Mine spins up until the engine warms up and then shuts off.

 

Probably an idler. i have a similar issue and it is an idler that makes noise on cold mornings. After running for a couple minutes it's gone

 

Chatter or more of a plasticly rattle down by the gas pedal part of the engine bay? I get the same thing when it's cold, but never have been able to really track it down.

 

mine makes clackity sounds on the first startup of the morning, always has, uses no oil never an issue... just run it.

 

Appreciate all the help !

 

Sounds like a belt or idler. My Tundra has an idler that is noisy when it's really, really frigid but goes away in about 5 minutes. The noise is a little more high pitched. Chattering, like chipmunks or squirrels mating, is not uncommon when belts are starting to reach their end of life.

Cheers.

 

At least replace the tensioner pulley for $30, now instead of waiting for it to explode and fuse itself together forcing you to replace the tensioner assembly for $130 plus probably a new belt. Good luck!

 

Good idea ! I'll do that thanks !