On my 99 Dodge Ram 1500 I hear a chirping sound coming from under the hood; can't pinpoint it yet. I'm thinking it is probably an idler pulley, tensioner, maybe?
It is faint when the truck idles, and gets a little louder and more consistent when accelerating. When cruising it's not there.

I don't think it's pre-ignition...

Any suggestions?

 

Would like to know what this could be as well. I was like you. Idler pulley or belt.

 

most likely a bearing in a pulley. take you belt off and spin some pullies around and see if you hear anything..

unless theres some scared sh*tless birds that made a home in there lol

 

mine does the same thing but goes away after it is warm and that is after i replaced the tensioner pully and idler pully

 

Could be a few things, fan clutch could be going bad also could be the bearings in the water pump or could possibly be just the belt riding back and forth on the pully's. Check and see if you have any abnormal belt wearing or dusting on the sides of the belt

 

I have the same thing. Only happens on a cold start up. Goes away after a few minutes.

 

Mine would make a loud whine only when cold. I removed the idler pulley and spun it while holding it. It was kinda rough so I replaced it with a new one from Napa. Problem solved. I removed the dust cover from the old one and greased it up and threw it in the toolbox just in case.

 

hi, i changed the belt tensioner, i just installed a new water pump, i greased all the zerks today and it still squeeks and chirps but only when i engage it into reverse or drive....as soon as its in park... it quiets right up...please help my truck is already embarrassing enough as it is....worse with the noise...

 

Find the bird.

In all seriousness though, a bit of dirt in one of the pulleys will give you the chirp, as well a failing bearing in the idler pulley.

 

I'm a mechanic. We had a 07 ram come in chirping away. Took the belts off started it. Still chirping. Had to replace the cam in it. Then the chirping stopped and replaced a pulley, but the pulley wasn't the issue