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Discussion Starter #1
Hello,

I have a 2015 scat pack, about 55k miles on it.

I have noticed a weird sound when cruising EXACTLY between 48 - 52 MPH. Never does the sound appear under or above that speed.

It's like droning/huming noise with a period of about 1 second repetition. Unfortunately I could not record the sound, it's just not intensive enough.

It doesn't seem to matter if i am accelerating/decelerating/going without gas pedal pressed.

It doesn't always appear, but most of the time it does, always just in the above speed.

I just got new brakes (rotors and pads) if that helps. But I think the sound appeared even before that, I just didn't pay enough attention.

Any ideas? Thanks.
 

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Hello,

I have a 2015 scat pack, about 55k miles on it.

I have noticed a weird sound when cruising EXACTLY between 48 - 52 MPH. Never does the sound appear under or above that speed.

It's like droning/huming noise with a period of about 1 second repetition. Unfortunately I could not record the sound, it's just not intensive enough.

It doesn't seem to matter if i am accelerating/decelerating/going without gas pedal pressed.

It doesn't always appear, but most of the time it does, always just in the above speed.

I just got new brakes (rotors and pads) if that helps. But I think the sound appeared even before that, I just didn't pay enough attention.

Any ideas? Thanks.
Last thing touched is always first thing suspected...

You sure all the wheel lugs have been properly torqued?

If you are not sure the noise was present before you had the brakes done -- who did the brakes? -- you need to have the brakes inspected. Maybe a pad is not seated properly, or some brake hardware -- the pad retaining clip -- is loose or broken one or both pads are loose and account for the noise.

If you are sure the brakes are ok, and not the source of the noise, the next thing that comes to mind is a wheel bearing can account for the noise with the period of repetition of in this case 1 second. I do not know why, exactly.

While it is a bit of work -- but it is worth it to confirm/eliminate wheel bearing problem -- arrange to raise the car by its factory sanctioned lift points so the wheels/tires are unsupported and bear no weight and give each wheel/tire a wiggle as you rotate the wheel/tire to check for any signs of bearing play.

Have not needed this level of attention yet for my Dodge but with my other cars the local dealer service department would accommodate me and put the car on a lift and give it a "road worthiness" inspection at no cost. I had both my cars serviced there and always offered to pay for the shop's time and every time the shop refused to bill me. One senior tech told me because I offered pay for the time I was not charged.

At any rate you need to consider a bad wheel bearing and arrange to be able to or have some one check the car for any loose/wobbly/wiggling wheels/tires.

The car has of course 4 wheels/tires. The odds are there will be only one with any play. 'course, you may find no play. This doesn't necessarily mean the wheel bearings are in the clear though. I had a car that manifested what proved to be a wheel bearing noise -- only audible after I had replaced all 4 worn/noisy tires -- but the noisy wheel bearing did not have any play.

Are the tires properly inflated?

While you have the car in the air check the tires for any signs of tread separation, or anything out of the ordinary. I mentioned the wheel lugs above.

Also, from under the car check all plastic panels / wheel well liners are secure and can move about/vibrate or get pulled out of position by the wind as the car moves down the road.
 

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Discussion Starter #3
Thanks for a lengthy answer. Now I can't, but will properly read it later.

I am almost sure it's not the brakes.

It might be tires though - all my tires show about 34 value (honestly now I am not sure what unit that is) on the board computer, right front one is always 1-2 less. Could that be the issue?
 

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Thanks for a lengthy answer. Now I can't, but will properly read it later.

I am almost sure it's not the brakes.

It might be tires though - all my tires show about 34 value (honestly now I am not sure what unit that is) on the board computer, right front one is always 1-2 less. Could that be the issue?
The "34" value I expect is air pressure. The right front reading being 1 to 2 (psi) less could possibly (maybe, perhaps) account for some noise. I see the air pressures of my car's tires differ some but no more than 1 psi which arises from the difference in how fast they warm up and the delay arising from the RF link between the tire pressure sensor and the antenna that receives these transmissions.

Regardless, as best I can tell this 1psi or thereabouts difference in pressure does not produce any odd or excessive/abnormal noise.

In these cases I like to leave nothing to chance.

You should strive to have all 4 tires inflated to the correct cold tire pressure when cold, after sitting over night.

I use a tire pressure gauge to get the tire pressures to as close to the right or desired setting as reasonably possible.

There is a tag in the car -- on the door jam or in the glove box or this info should be in the owners manual -- what the proper inflation pressure should be. The 2 Dodge Challengers I have owned this as been 32psi.

I would not play games at least not right now and adjust all 4 tire pressures to the correct cold inflation pressure. I have found with at least one previous car just a few PSI over the factory recommended cold tire inflation pressure caused a vague tire imbalance vibration. Thus it would not surprise me the noise might arise from improperly inflated tires.

If after you get all 4 tires properly inflated then if you see one tire pressure different from the rest, lower, this suggests a slow leak. This needs to be investigated and dealt with.
 

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Discussion Starter #5
Sure, I will try to correct the tire pressure asap. That's something I can do on my own.

However, if the issue I am having is not caused by this (and it's let's say any of the other potential causes suggested above), is it safe to drive my car until this is dealt with? Or it could potentially be something really dangerous?

The issue is, I live in Europe, not the US, so getting to a proper mechanic experienced with US cars is not that easy. Sure, there are some specialist shops close enough to visit for me, but it's not a thing I can just do in a day or two. So my question is if it's fine if I drive the car till I get a proper inspection by an US car specialist, or it's better to not drive the car at all in the meantime. Thanks.
 

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Sure, I will try to correct the tire pressure asap. That's something I can do on my own.

However, if the issue I am having is not caused by this (and it's let's say any of the other potential causes suggested above), is it safe to drive my car until this is dealt with? Or it could potentially be something really dangerous?

The issue is, I live in Europe, not the US, so getting to a proper mechanic experienced with US cars is not that easy. Sure, there are some specialist shops close enough to visit for me, but it's not a thing I can just do in a day or two. So my question is if it's fine if I drive the car till I get a proper inspection by an US car specialist, or it's better to not drive the car at all in the meantime. Thanks.
I am not qualified to answer that question. The noise may be from something relatively benign or it can be due to pending serious problem. Maybe with the brakes, a safety critical system to state the obvious.

If the noise was not present until after the brakes were done this suggests something regarding the brakes is not right.

If you can't be sure the noise was present only after the brakes were done but could have been present before the brakes were done this suggests the noise is not a sign something dire is about to happen, but I can't offer any advice in this regard.

When in doubt given so much is at stake my SOP is to err on the side of caution and get the car in the hands of an expert mechanic ASAP. With as little usage of the car in the meantime as possible.
 

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Discussion Starter #7
I am pretty sure, but not 100 percent of course. Honestly, I got the car just recently and due to the covid issue I didn't have many possibilities to drive it around except just in the city (where I never reached the problematic speed). The two or three times I took it out to the highway, there WAS a weird sound bothering me. However I didn't focus on it as the car was just so new to me (and I moved from a 160hp to 485hp car so it was a little "scary" for me) that my hands and mind were just too full of the new experience. Also the car is very loud as such, it has mufflers removed. So for me those few times were very overwhelming from the sounds perspective. I could not that easily tell what sound is ok and what is not. I am no car expert and it's my second car ever. I just didn't know what a proper scat pack is supposed to sound.
Only today I went for a longer trip for the first time after getting a little bit acquainted with the car (and first one after getting new brakes), so i had time to focus on this and to locate the exact conditions under which it happens. So I am pretty sure the sound was there before, I just didn't focus on it.
 

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Discussion Starter #8
However you scared me enough, I must admit, so i will try my best to get it to a mechanic asap.
 

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However you scared me enough, I must admit, so i will try my best to get it to a mechanic asap.
Not my intent to scare you. Just make you aware of what the decision to continue to operate the car with this noise might entail.
 

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Its probably the mds your hearing. It will make the engine carry a different sound when it switches over. Have you changed exhaust or deleted the mids? Is it auto or manual?
 

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Discussion Starter #12 (Edited)
It is AT. And it has removed mufflers as I was told by the previous owner.

MDS was the first thing that popped in my head. However I don't believe it is the cause of the sound. The 4 cylinder mode is displayed on the screen if active and the occurrence of the sound did not seem to be correlated with the mode being on or off.
 

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It is AT. And it has removed mufflers as I was told by the previous owner.

MDS was the first thing that popped in my head. However I don't believe it is the cause of the sound. The 4 cylinder mode is displayed on the screen if active and the occurrence of the sound did not seem to be correlated with the mode being on or off.
I think it has to do with the mufflers being removed.
 

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Yeah if its happening just at a certain mph (i would check the rpm’s too) it sounds like run of the mill exhaust drone
 

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Yeah if its happening just at a certain mph (i would check the rpm’s too) it sounds like run of the mill exhaust drone
As trippytro stated check RPM... use a different gear to hit the same RPM as in drive at 48-52 Mph. It seems like a pretty tight window for drone but it could be. The other thing is you could be hitting the sweet spot for the rear differential to whine. if it's only at that speed and not a specific RPM that could be it. Not sure if that is much of an issue with the ZF rear diffs, but wouldn’t hurt to rule it out.
 
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