Metallic hissing, sounds like a dry rollerblade bearing 25 - 45mph

[basicGlad]

A little while ago I started to hear a scraping, metallic hissing like a dry rollerblade bearing spinning. I cannot describe it well other than it's very faint, very quiet. I thought it was front passenger but "the noise comes from lower" is a better description.

I don't hear it above 50mph because I have a soft top at that point I only hear wind noise. I don't hear it below 20mph. I do hear it 25-45mph. The engine RPMs are louder than the noise I'm hunting down. But HVAC, radio and manual transmission in neutral you hear it.

I had a service appt today. Mechanic rode with me when I dropped it off. He said he couldn't hear it and said everything looked fine but I had rusty enough rotors that's where the noise was coming from. So I agreed to have the rotors turned. Still making the noise. Service writer rode with me and said "yeah very quiet but I do her it" but from the passenger seat he thought it was middle to back.



Anyone had something similar? Or suggest anything to test? My next idea is put a GoPro next to the carrier bearing/mono block.

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[jac04]

A little while ago I started to hear a scraping, metallic hissing like a dry rollerblade bearing spinning. I cannot describe it well other than it's very faint, very quiet. I thought it was front passenger but "the noise comes from lower" is a better description.

I don't hear it above 50mph because I have a soft top at that point I only hear wind noise. I don't hear it below 20mph. I do hear it 25-45mph. The engine RPMs are louder than the noise I'm hunting down. But HVAC, radio and manual transmission in neutral you hear it.

I had a service appt today. Mechanic rode with me when I dropped it off. He said he couldn't hear it and said everything looked fine but I had rusty enough rotors that's where the noise was coming from. So I agreed to have the rotors turned. Still making the noise. Service writer rode with me and said "yeah very quiet but I do her it" but from the passenger seat he thought it was middle to back.



Anyone had something similar? Or suggest anything to test? My next idea is put a GoPro next to the carrier bearing/mono block.

Any follow-up on this? I'm trying to track down a similar faint noise as well. I also have a 2021 Mojave. I start to hear it at about 40, then it gets most noticeable at 46-47mph, then seems to disappear.

I thought about the rear driveshaft carrier bearing, but my rear driveshaft was replaced die to loss of a balancing weight, and the noise did not change at all.

Do you have Selec-Trac? I'm wondering if it could be related to this system somehow.

 

[spectre6000]

Is it a constant frequency, does it rise/fall directly with wheels, or does it rise/fall independent of wheel speed?

 

[basicGlad]

No Selec-Trac, I have a Sport S made Sept2019. Just 4hi & 4lo

I would say mine is a constant frequency (the sound itself doesn't wobble). It only gets a tiny bit louder from the speed it appears until the wind noise (soft top) is too loud you cannot hear anything else.

One day I'll stick a GoPro under my truck.

 

[spectre6000]

That it's a constant speed regardless of vehicle speed rules out anything related to the drivetrain. Any and all parts would change with speed.

Think of other things that spin independently: AC fan, engine fan, sometimes speakers will make weird noises they shouldn't electronically...

 

[basicGlad]

I mean, It shows up around 30 mph and you can hear it until 50mph. Then you only hear wind noise

"I do hear it 25-45mph. The engine RPMs are louder than the noise I'm hunting down. But HVAC off, radio off and manual transmission in neutral you hear it."

 

[Musser717]

Anyone every find anything out about this? Been having a similar issue after new wheels and tires, no one can seem to figure it out.

 

[ShadowsPapa]

Wheels or weights rubbing calipers? That sound would change with speed and not be constant, though.

 

[TrainMan]

Shield under the frame maybe vibrating at certain frequencies around those speeds?

 

[Musser717]

Wheels or weights rubbing calipers? That sound would change with speed and not be constant, though.

I’ve had it at the dealership and they supposedly checked all my brakes and rotors. Dealership conned me into changing my rear diff fluid saying that was it. It wasn’t. I took it back and took a ride with the tech and surprise there was no noise for another couple days but it was raining that day. I don’t hear the noise with the windows down even a little bit.

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