Resonance at around 70 MPH?

[Subie]

I just picked up a DZE SSM BRZ today and everything seems to be great except for one potential concern: the car is noticeably louder at speeds at/near 70 MPH. It sounds like a resonance coming from the rear of the car, possibly the rear end but not necessarily. Has anyone else noticed anything similar?

Anyone with this issue, please see this post!

8/22 Big update! See post #55!
11/19 Another visit with the district rep!
11/20 New differential ordered!

[clayrush]

When I am 70-80 I can hear a sort of high pitch wine. I had the same thing in my celica.

[Subie]

This noise isn't that high-pitched, and I wouldn't really characterize it as a whine. It's more of a drone than a whine. I hear that high-pitched whine, too, but it doesn't concern me.

[Draco-REX]

There's a slight resonance I hear, but usually only if I have the rear seat down. The stock tires are pretty noisy for a "touring" tire. I think it's due to the tire's "low rolling resistance" nature.

Remember, this car has MUCH less sound deadening than most any other car you'd buy these days. It keeps the weight down as well as cutting a bit of cost. But the trade off is increased noise from the drivetrain and road.

[Subie]

I'm perfectly fine with it if it ends up being the tires; I just want to pinpoint the source so that if it's something more serious it can be addressed. I'm hearing this with the rear seat up, and it's hard to miss.

[ToxicSneakers]

Originally Posted by Draco-REX

There's a slight resonance I hear, but usually only if I have the rear seat down. The stock tires are pretty noisy for a "touring" tire. I think it's due to the tire's "low rolling resistance" nature.

Remember, this car has MUCH less sound deadening than most any other car you'd buy these days. It keeps the weight down as well as cutting a bit of cost. But the trade off is increased noise from the drivetrain and road.

What he said.

[cwik]

Originally Posted by Subie

Has anyone else noticed anything similar?

There's a wide variety of surface types surrounding Seattle and on some roads (especially grooved roads), I have noticed a droning noise. It concerned me initially, but then the road surface changes to another type, and voila, it's gone .

FWIW, I've also noticed it at much lower speeds too, like 40 mph.

[Subie]

Originally Posted by cwik

There's a wide variety of surface types surrounding Seattle and on some roads (especially grooved roads), I have noticed a droning noise. It concerned me initially, but then the road surface changes to another type, and voila, it's gone .

FWIW, I've also noticed it at much lower speeds too, like 40 mph.

The thing is though, I drove on a variety of pavement types on my drive home from the dealer. No matter what pavement I was on, the noise was there at ~70 MPH+. I would think it would go away on the smoothest pavement but it didn't. I guess I'll monitor it and see if it changes at all.

[Subie]

I took the car to the dealer and a technician drove the car and found nothing amiss. I should have insisted on riding with him but sadly did not; I want the noise in question noted so even if it's not a real concern I'll know that the dealer has in fact heard it.

Of note is that at half the speed, 35 MPH, I notice a resonance, too. Theoretically there will also be a resonance at 140 MPH but that is something I cannot check for obvious reasons. Can anyone else go test their BRZ at 35 MPH in 4th gear to see if there is any resonance from the drivetrain?

[Subie]

I drove the car on a long highway trip yesterday and unfortunately was dealing with 65 MPH & 70 MPH speed limits, putting me very close to the peak resonance range. I had to avoid going 67-73 MPH as that's the range in which it drones the most and it gets very tiring going those speeds. I'll have to put my foot down when I get back home-- something is definitely amiss.

[rmjjensen]

I think I am also experiencing the same thing you are. To me, it sounds more like a humming sound that would indicate a bad wheel bearing.

As others said, I think it's just due to the fact that a lot of road noise (and noise in general) is able to enter the cabin very easily in this car.

[Subie]

Originally Posted by rmjjensen

I think I am also experiencing the same thing you are. To me, it sounds more like a humming sound that would indicate a bad wheel bearing.

As others said, I think it's just due to the fact that a lot of road noise (and noise in general) is able to enter the cabin very easily in this car.

It's definitely not road noise; it's something from the drivetrain. My car also seems to have a cyclical vibration at 40+ MPH which may or may not be related. At 35 MPH is 4th gear I can hear the noise but it sounds cyclical, whereas at 70 MPH it's a constant hum.

[Subie]

I took the car to the dealer again today to have the noise addressed. I easily pointed the noise out to a technician both at 35 MPH and at 70 MPH but the dealer told me they couldn't find anything wrong with the car when I picked it up. I'm supposed to be meeting with the district rep. sometime this month but really, it shouldn't have come to this.

[Subie]

Originally Posted by rmjjensen

I think I am also experiencing the same thing you are. To me, it sounds more like a humming sound that would indicate a bad wheel bearing.

As others said, I think it's just due to the fact that a lot of road noise (and noise in general) is able to enter the cabin very easily in this car.

I'd like to get some more information from you to see if the noise you're experiencing is exactly the same as mine or very similar. Would you mind posting in the thread I made earlier and providing answers to the following questions?

1) What speed range do you hear the noise? For me, I hear it mainly from 67-73 MPH, and it's loudest right at 70 MPH. The noise is barely audible outside of that range.

2) Do you hear the cyclical noise at 35 MPH that I described in the thread? Basically take the noise you're hearing at 70 MPH, and see if you hear anything similar at 35 MPH.

I have a case open with Subaru of America about this issue because my dealer was completely unresponsive, telling me that everything checked out OK. Would you be willing to contact Subaru about this issue (I'll provide you with a contact person and reference number) to add credibility to my case? It can only help you, too, as it will make it more likely that a fix will be developed.