Chirping sound at idle.

[Shopshirt]

My truck started making a chirping sound at idle. It doesn't sound like a pulley. It sounds like one of those kids whistles that you put water. Anyone experience something similar? I've read somewhere that the 240amp alternator may make chirping noises but that is the only thing my search pulled up.

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[Maximus Gladius]

Auto or manual transmission? MILAGE? Noise coming from below or at the engine?

 

[Mac]

Try spraying some belt dressing on the belt and see if it stops.

 

[Shopshirt]

Auto 2400 miles sounds like it is coming from the top front. I'll try to grab a video when it does it again. Doesn't seem to happen all the time.

 

[Maximus Gladius]

What Mac said. If that doesn’t work, pick up a mechanic stethoscope to find ground zero.

 

[ShadowsPapa]

You woke the sparrows in their nest when you started it.
Seriously, though - chirp most likely bearing, belt, or something dry. Try also to determine if the cycle of chirps matches anything else - is it chirping in perfect unison with the engine RPM, for example?
Maybe make a chalk mark (Small, but big enough to see) on the back side of the belt so you can see it and see if the chirps are timed with the belt going around, does the chirp change or go away if you just barely take it off idle?

I don't know where you saw that alternators "chirp" but there's nothing about any alternator that will make any sound at all other than - bearings or belt on the pulley. They are electrical devices, the only mechanical thing about modern alternators are the bearings and the rotor that spins inside but it doesn't touch anything at all so it's going to generate a chirp.
There's also nothing specific about the 240 vs, say, a 180, that would cause it to chirp and others not.
If I hear an alternator chirp I'd be yanking it off the engine and getting bearings replaced. (or checking to see if it's the belt)

 

[Shopshirt]

You woke the sparrows in their nest when you started it.
Seriously, though - chirp most likely bearing, belt, or something dry. Try also to determine if the cycle of chirps matches anything else - is it chirping in perfect unison with the engine RPM, for example?
Maybe make a chalk mark (Small, but big enough to see) on the back side of the belt so you can see it and see if the chirps are timed with the belt going around, does the chirp change or go away if you just barely take it off idle?

I don't know where you saw that alternators "chirp" but there's nothing about any alternator that will make any sound at all other than - bearings or belt on the pulley. They are electrical devices, the only mechanical thing about modern alternators are the bearings and the rotor that spins inside but it doesn't touch anything at all so it's going to generate a chirp.
There's also nothing specific about the 240 vs, say, a 180, that would cause it to chirp and others not.
If I hear an alternator chirp I'd be yanking it off the engine and getting bearings replaced. (or checking to see if it's the belt)

Damn sparrows lol. It goes away when I increase rpm above idle. The alternator thread was the only one I could find that was similar. It doesn't do it until I drive it for awhile.

 

[Fastwake]

Parakeets

 

[ShadowsPapa]

 

[Shopshirt]

It's intermittent and only at idle. Sounds almost like a whistle here's a clip.

 

[Maximus Gladius]

That’s not a chirp or the belt. That sounds like a bearing. If you had a stethoscope you’d know if it’s from the alternator or idler pulley wheels. I had to replace a pulley wheel already and it sounded just like that.

 

[Maximus Gladius]

Look close at those pulley wheels to see if it looks like the seal went bad and the face of them is greasy/dirty.

 

[Shopshirt]

Thanks I'll take a look. Surprising at 2400 miles.

 

[Maximus Gladius]

That’s is early if that’s what it is but that’s the same sound I had.

 

[Shopshirt]

The Verdict is...

Water Pump, ?

local dealer ordered one and waiting on a Parts ETA. I can drive it unless it starts leaking coolant or overheating.

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