# Rhythmic Humming Noise at Highway Speeds **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** outback, noises, subaru\ **Created:** [September 26, 2024, 4:52pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416 "2024-09-26T16:52:02Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![allycat312\_191423](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@allycat312\_191423](https://community.cartalk.com/u/allycat312_191423)\ **Post date:** [September 26, 2024, 4:52pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/1 "2024-09-26T16:52:02Z")
Hi, I need serious help. I have a 2013 Subaru Outback that since I bought it, has had a rhythmic humming noise/vibration when at highway speeds (55-70). Sounds like a hum, hum, hum once per second. Vibration doesn’t shake the wheel, but you can feel it in the floorboards. Rhythm gets faster when driving around a curve to the left, quieter when curving to the right. I’ve taken it to several shops (including a Subaru dealer) and was told it is not the wheel bearings and those are fine. They told me it was because the tires were cupped and new tires would fix it, but getting new tires did not fix the noise. Firestone said my alignment was good when they mounted my new tires too, so I don’t think it’s an alignment issue. Suspension feels fine, not crazy bouncy or anything. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [September 26, 2024, 4:53pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/2 "2024-09-26T16:53:49Z")
First guess-rear wheel bearings ---
**Author:** ![allycat312\_191423](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@allycat312\_191423](https://community.cartalk.com/u/allycat312_191423)\ **Post date:** [September 26, 2024, 4:58pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/3 "2024-09-26T16:58:05Z")
The dealership and a local shop said all wheel bearings are fine. Also neglected to say I feel like it’s coming from the front, not the back of the car. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [September 26, 2024, 5:17pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/4 "2024-09-26T17:17:18Z")
> [@allycat312\_191423](#): > > The dealership and a local shop said all wheel bearings are fine Did they check all 4, or just the rears, which, on this car, fail often. As time goes on, if that noise gets worse, have the wheel bearings checked again. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 26, 2024, 5:19pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/5 "2024-09-26T17:19:03Z")
When was the last time the transmission fluid was serviced? Same goes for the rear differential? Tester ---
**Author:** ![ledhed75](https://avatars.discourse-cdn.com/v4/letter/l/f6c823/32.png) [@ledhed75](https://community.cartalk.com/u/ledhed75)\ **Post date:** [September 26, 2024, 5:38pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/6 "2024-09-26T17:38:55Z")
Differential was my first thought too. If it’s not the tires or the wheel bearings, differential has to be next. Unfortunately, probably the most expensive possibility… ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [September 26, 2024, 10:09pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/7 "2024-09-26T22:09:44Z")
My Corolla had a similar problem, thought at first it was a wheel bearing, but I noticed that all 4 tires were worn to the point they needed replacing anyway, so I did that first. Problem solved, noise turned out to be a tire problem. In my case I could hear it more clearly at lower speeds. Since you’ve proved it isn’t the tires, next most likely, I’d say that is still a faulty wheel bearing. It isn’t always possible to determine this with standard shop techniques, checking for play, listening to the wheels when you spin them by hand, and the only was to prove it is caused by the wheel bearing is to replace it. ---
**Author:** ![cigroller](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@cigroller](https://community.cartalk.com/u/cigroller)\ **Post date:** [September 27, 2024, 12:22am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/8 "2024-09-27T00:22:37Z")
Hopefully whatever shops it’s been to have checked that the inner fender liners are securely attached, but who knows? Theoretically speaking if one was a little loose and catching some wind it could be rubbing on a tire. I don’t think of that as being highly likely, but I wouldn’t rule it out 100%. And with the noise worse turning left it would likely be on the left side. Alternatively, what george said above is relevant. A marginal wheel bearing might not show any issues without the full weight of the car on it. The normal way it would present isn’t with a rhythm getting faster or slower when turning, but noise getting louder or more quiet. Worse on a left turn implicates a right bearing. But in my experience, they also tend ot be loudest in the 45-55mph range. So I’m not sure that’s all that likely either. Tester asked about the trans fluid and differential…what answers can you give for that? ---
**Author:** ![Cavell](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cavell/32/43396_2.png) [@Cavell](https://community.cartalk.com/u/Cavell)\ **Post date:** [September 27, 2024, 12:37am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/9 "2024-09-27T00:37:35Z")
Wheel bearing or tires. Things that support vehicle weight and spin. ---
**Author:** ![allycat312\_191423](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@allycat312\_191423](https://community.cartalk.com/u/allycat312_191423)\ **Post date:** [September 27, 2024, 1:49am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/10 "2024-09-27T01:49:22Z")
I just got this car last year, but the carfax looks like “transmission was checked” at ~51k miles. Car is now at 119k miles. I don’t see anything in the carfax specifically noting work on differentials. 120k mi service from Subaru does recommend transmission fluid change and differentials serviced. ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [September 27, 2024, 2:26am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/11 "2024-09-27T02:26:03Z")
1st off, remember that Carfax can only report what has been reported to them… > [@allycat312\_191423](#): > > Rhythm gets faster when driving around a curve to the left, quieter when curving to the right. That is a tell tell sign of a bad right front wheel/hub bearing… And the bearing does not have to be loose to make noise… You should be able to spin the tire/wheel and feel the coil spring for any vibration on a noisy hub/wheel bearing… When you turn left (just a curve in the road) you are loading the right front wheel bearing and it will make more noise… When turning right you are loading the left wheel bearing and it will make more noise and the right front bearing noise will decrees… I have also seen transaxle diff and diff bearings do this also… Probably gonna have to find a shop with Chassis Ears in order to find the noise… ---
**Author:** ![allycat312\_191423](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@allycat312\_191423](https://community.cartalk.com/u/allycat312_191423)\ **Post date:** [September 27, 2024, 2:38am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/12 "2024-09-27T02:38:49Z")
I agree that all signs point to wheel bearing from all research I’ve done. However the dealer, a local shop, and a friend checked them and said they seem fine. Dealership said he used stethoscope to listen to them, friend did a manual check with car jacked up and didn’t find an issue either. ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [September 27, 2024, 3:52am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/13 "2024-09-27T03:52:16Z")
> [@allycat312\_191423](#): > > Dealership said he used stethoscope to listen to them Did the dealer not find the noise issue then?? Or did you just have them check the bearings instead of having them properly diagnose the noise complaint?? Next time, set a waiting appointment and have them (whoever) check for a noise while driving instead of helping them, and then when (if) they find the noise, ask them to show it to you… Only ever give a shop symptoms, never a diagnoses, they will look harder… ---
**Author:** ![allycat312\_191423](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@allycat312\_191423](https://community.cartalk.com/u/allycat312_191423)\ **Post date:** [September 27, 2024, 6:05am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/14 "2024-09-27T06:05:21Z")
I told the shop I had this noise and asked them to tell me what it was and they just told me that it was excessive road noise from driving on cupped tires and that new tires would fix it. Which ended up not being the case. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [September 27, 2024, 6:35am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/15 "2024-09-27T06:35:55Z")
Now that the tire noise is eliminated, maybe someone can identify the sound. Some vehicle owners have more sensitive hearing than most technicians. A technician isn’t going to rush to judgement and replace wheel bearings or a CVT for a noise that is not intrusive. ---
**Author:** ![ledhed75](https://avatars.discourse-cdn.com/v4/letter/l/f6c823/32.png) [@ledhed75](https://community.cartalk.com/u/ledhed75)\ **Post date:** [September 27, 2024, 10:24am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/16 "2024-09-27T10:24:44Z")
Go and get the transmission fluid and differential service done. Sounds like it may never have been serviced, or at least you can’t say for sure. It won’t hurt anything (except your wallet), and can only help. It may also fix your problem. ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [September 27, 2024, 12:50pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/17 "2024-09-27T12:50:56Z")
You did replace all 4 tires correct?? As Nevada said, now that the tires (hopefully all 4 if over 3/32 difference) take the vehicle back to the dealer or repair shop and have the noise complaint properly diagnosed now… Remember Firestone rotates your tires every 5K miles for free, make sure to keep the maintenance up on them so they don’t cup up on you again… ---
**Author:** ![allycat312\_191423](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@allycat312\_191423](https://community.cartalk.com/u/allycat312_191423)\ **Post date:** [September 27, 2024, 1:15pm UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/18 "2024-09-27T13:15:32Z")
Yep, got all 4 new tires. Just took it in to a shop today to hopefully diagnose the issue. And yeah, once I got the car I was good about rotating the tires. They were cupped when I got them. ---
**Author:** ![jmcarc](https://avatars.discourse-cdn.com/v4/letter/j/278dde/32.png) [@jmcarc](https://community.cartalk.com/u/jmcarc)\ **Post date:** [October 5, 2024, 2:13am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/19 "2024-10-05T02:13:17Z")
“Rhythm gets faster when driving around a curve to the left, quieter when curving to the right.” I think you have a bad wheel bearing on the right side of the car. When you curve to the left, the weight of the car shifts to the right wheels, which makes the noise worse. ---
**Author:** ![cigroller](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@cigroller](https://community.cartalk.com/u/cigroller)\ **Post date:** [October 5, 2024, 2:24am UTC](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416/20 "2024-10-05T02:24:39Z")
> [@jmcarc](#): > > I think you have a bad wheel bearing on the right side of the car. When you curve to the left, the weight of the car shifts to the right wheels, which makes the noise worse. Yeah, that’s what EVERYONE was thinking. And I sometimes miss things in what people post too, but there’s this in the OP: > [@allycat312\_191423](#): > > I’ve taken it to several shops (including a Subaru dealer) and was told it is not the wheel bearings and those are fine. Could it still be a wheel bearing that is very early on in failure? Sure. It’s been brought up again and again in the whole thread. [Next page](https://community.cartalk.com/t/rhythmic-humming-noise-at-highway-speeds/196416.md?page=2)