Constant Chirping While Idling

[jwilinski]

My 2005 Jeep Liberty CRD constantly chirps like a high pitched bird sound while idling but not when driving. The vehicle runs very well (except has a hot start issue) What could this chirping be?

 

[seafish]

Serpentine belt or one of the pulleys it runs around is going bad.

You can spray lightly soapy water on it while running to find out for sure.

 

[jwilinski]

Okay. What am I looking for when I pour the soapy water on it?

 

[seafish]

Dont just pour water on it...use a spray bottle set to "stream" for more accuracy around the pulleys.
The soapy water temporarily lubes the belt and squeak will go away if the belt is bad.
If it doesnt go away, then something else is causing the squeak.

 

[seafish]

If it is the serpentine belt, then when it’s off for replacement, you’re gonna wanna check each and every pulley (except the crankshaft) that it runs around for excessive looseness or roughness or tightness while spinning them by hand since they eventually go bad and will lead to belt wear and early failure or fail catastrophically themselves.

Also note that the belt tensioner spring can be bad and lead to a belt squeak so it’s usually a good idea to replace it with the belt unless you happen to know that it was already replaced within its service life.

 

[reload40s]

Also, when you pull the belt off and spin the pulleys you might not hear the exact same sound of squeaking even if they are bad. They usually only sing under belt tension. You can feel the rumbling and not smooth turning bearing very easily though. I agree about replacing the tensioner with the belt. It is a worthwhile $75 to $100 investment