Super Soft Squeak Chirp

[HowAboutThis]

2017 Corolla 75k miles. Normally I drive with windows up so hadn't heard this before today. When driving with cars or a barrier to reflect sound back, there was a super quiet, rhythmic "chirpchirpchirpchirp" kind of chirp squeak thing. Definitely changes with wheel speed. But so quiet you can't hear it unless there's an object, like a car or wall, next to the road when driving and the passenger window has to be down. On other cars wheel bearings have made a growl. Lower pitched like a grinding growling sound. Not the same sound. It also doesn't go away when I put the brakes on. At first I thought it was just a slightly rubbing brake pad, until putting the brakes on didn't change it.

Ideas? With windows up and radio softly playing I probably have thousands more miles of ignoring...

 

[MattPersman]

Would still inspect the brakes

 

[rcs]

I am not a mechanic,...does it happen when you are stopped at idle?

 

[HowAboutThis]

I am not a mechanic,...does it happen when you are stopped at idle?

No. But it sounds like a belt on a car with a quiet "chirp chirp chirp" when it is a belt on a car. Very similar pitch and chirp to a belt.

I'm going to do the whole wheel check for play and spin it one of these evenings to see if anything is noticeable.

 

[HowAboutThis]

But there's no pulling to either side when braking, no vibration at highway speeds, no feeling of looseness while driving. I thought it was a slightly rubbing brake pad or some dust or dirt making a noise in a brake or something. But normally I've had noise like that change pitch or cadence when applying the brake. This doesn't.

 

[HowAboutThis]

And after my 25 miles all freeway commute I took the plastic hubcap off and touched the center of the tire. Warm, but by no means hot. So nothing seemed weird there. Did a quick touch of the brake calipers and both were hotter than the hub (from using brakes on the way home) but I could keep my hand on it without screaming...

 

[D60]

Last time I got that from the rear of an '02 Silverado it was the pad tattles. Could only hear it when sound was bouncing off median dividers, etc. Could not detect "in the open"

 

[PF52]

I've had rotors develop rust on the outside circumference, enough so that eventually the rust started to lightly contact the underside of the caliper. Just a couple high spots in the rust really.... But upon removing the caliper and looking at the underside of it, there was a shiny spot there where the rust had been contacting it (and making a high-pitched squeak-chirp). A little work with the angle grinder (on the rotor) cured the noise.