Mach e hurts my ears

[MrLoganRoss]

Turn off propulsion sound

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[Manfredo]

But you never know. When you mentioned repair manual is that referring to the dynamite?

Sorry I meant dynamat. Ha! I have tried venting at 1 or 2 not circulating, especially when it’s cool out with no AC. It does seem to help a little. I’ll mess with the sub tomorrow. Everything feels less intense with the amp disconnected. Still feel like a light throbbing in my ear drum, only in the car. This def feels like a some personal medical thing but it only happens in this car. I’m getting closer to solving I think. Thanks again to all.

 

[Mach-Lee]

From the looks of it that is the only 'vent' in this car to the outside. The repair manual mentions:

NOTICE: The door windows must be left open during the adhesive curing time.
Open the vehicle windows to prevent the air pressure of closing doors from compromising the urethane adhesive bond.

Meaning there could be enough pressure from closing the door to cause adhesive to get pushed out like toothpaste. Yikes! But it makes sense as you wouldn't want to hear the road from wherever the little flappy flaps they used to install would be. It'd look like a small box with a plastic flap like a doggie door. Explains why the AC always reverts to fresh air intake. Any chance your car was ever in an accident?

No, there are cabin air extractor vents on each side under the bumper cover. It's the same setup as 99.5% of other cars. The car cannot become pressurized because those vents would let the air out. Air enters the vents on either side of the trunk panels and comes out through the vents in the rear fenders. See photo.

The service manual is referencing the brief pressure spike when slamming a door closed, which could dislodge a windshield that was recently set.

The subwoofer does not let air pass through it by design (otherwise it won't work right as a speaker). Air can only exit the cabin through those two exit vents below the taillights.

 

[Manfredo]

No, there are normal air extractor vents on each side under the bumper cover. It's the same setup as 99.5% of other cars. The car cannot become pressurized because those vents would let the air out. Air enters the vents on either side of the trunk panels and comes out through the vents in the rear fenders. See photo.

The service manual is referencing the brief pressure spike when slamming door closed, which could dislodge a windshield that was recently set.

The subwoofer does not let air pass through it by design (otherwise it won't work right as a speaker). Air can only exit the cabin through those two exit vents below the taillights.

Thank you!

 

[azerik]

No, there are cabin air extractor vents on each side under the bumper cover. It's the same setup as 99.5% of other cars. The car cannot become pressurized because those vents would let the air out. Air enters the vents on either side of the trunk panels and comes out through the vents in the rear fenders. See photo.

The service manual is referencing the brief pressure spike when slamming a door closed, which could dislodge a windshield that was recently set.

The subwoofer does not let air pass through it by design (otherwise it won't work right as a speaker). Air can only exit the cabin through those two exit vents below the taillights.

Unless the sub isn't mounted correctly, which was my thought. Oddly I wasn't able to find those vents in the repair manual (though I knew they had to be somewhere in the car). The questing about the accident was pertaining to weather any of these vents might be stuck closed or open. Closed, slowing building cabin pressure, or open (if possible) causing negative pressure from air being pulled out of the car or forced back in from the underbody panels or wheel wells. It was just an idea. There's several different symptoms in this thread.

 

[Manfredo]

Unless the sub isn't mounted correctly, which was my thought. Oddly I wasn't able to find those vents in the repair manual (though I knew they had to be somewhere in the car). The questing about the accident was pertaining to weather any of these vents might be stuck closed or open. Closed, slowing building cabin pressure, or open (if possible) causing negative pressure from air being pulled out of the car or forced back in from the underbody panels or wheel wells. It was just an idea. There's several different symptoms in this thread.

Thank you azerik, that’s interesting and will look into it. Anything is possible since it was a demo with 4500 miles on it but the dealership didn’t divulge anything and I did a vin check which came up clean.

 

[Manfredo]

That’s a good next step though to make sure there’s no obstruction between those cargo panels and the rear vents. That was one of the things they supposedly checked on one of my service visits but they gave a more generalized view of what they checked. I presume that would involve removing some exterior portions of the car like the bumper or side rear panel? (Sorry I don’t know a ton about car mechanics if that wasn’t clear from my previous posts if so I’m pretty positive they did not do that.

 

[azerik]

Yep, wheel well liner and/or the underbody panel. It’s a lot of small bolts but once off they could reach up to the vents. When I was in my gutted trunk last I didn’t see a way to get my hand down to the vents. I honestly don’t know how the sub venting to the wheel well is protected from water or air pressure. From my thought of it it’d be very hard for it to be an issue, but anything is possible.
Oh and I just found a tool. If you have a smart phone you could use the app Physics toolbox. There’s a barometer in there. I set to inHg and my bedroom yields 28.52 at about 2000ft above sea level. Weather app shows 29.7, so it’s off a bit. Higher the number the lower the pressure. You could set that on and change the time scale to the clock, recording a drive. Making note of when it got annoying and check the chart. It’d be very interesting to see if there’s a lack of pressure after a while. I’m driving into work tomorrow so I’ll give it a go as well for fun.

 

[Manfredo]

Yep, wheel well liner and/or the underbody panel. It’s a lot of small bolts but once off they could reach up to the vents. When I was in my gutted truck last I didn’t see a way to get my hand down to the vents. I honestly don’t know how the sub venting to the wheel well is protected from water or air pressure. From my thought of it it’d be very hard for it to be an issue, but anything is possible.
Oh and I just found a tool. If you have a smart phone you could use the app Physics toolbox. There’s a barometer in there. I set to inHg and my bedroom yields 28.52 at about 2000ft above sea level. Weather app shows 29.7, so it’s off a bit. Higher the number the lower the pressure. You could set that on and change the time scale to the clock, recording a drive. Making note of when it got annoying and check the chart. It’d be very interesting to see if there’s a lack of pressure after a while. I’m driving into work tomorrow so I’ll give it a go as well for fun.

Oh wow that is incredibly helpful. I will definitely try that. Thank you!!!

 

[corradoborg]

Higher the number the lower the pressure.

Sorry, minor correction: all units of pressure are direct scales. In other words, the higher the pressure increment, the higher the pressure.

You may be thrown by the fact that atmospheric pressure is inversely related to altitude. The higher the altitude, the lower the pressure (and, therefore, a lower number of inHg/pascals).

 

[Manfredo]

Sorry, minor correction: all units of pressure are direct scales. In other words, the higher the pressure increment, the higher the pressure.

You may be thrown by the fact that atmospheric pressure is inversely related to altitude. The higher the altitude, the lower the pressure (and, therefore, a lower number of inHg/pascals).

Got it. Thank you!

 

[azerik]

Sorry, minor correction: all units of pressure are direct scales. In other words, the higher the pressure increment, the higher the pressure.

You may be thrown by the fact that atmospheric pressure is inversely related to altitude. The higher the altitude, the lower the pressure (and, therefore, a lower number of inHg/pascals).

I felt my buddies eyes roll from my mistake all the way from the Adelaide BOM station lol.

 

[Bruboy]

Is the propulsion sound, interior, exterior or both?

 

[Manfredo]

Is the propulsion sound, interior, exterior or both?

Interior only

 

[Manfredo]

Just a quick update. On my last visit to the service center I asked them to disconnect the amp to see if that’s what it was and I noticed a sizeable difference so I brought it back this week and while they had it I asked them to check the rear vents which they did and found no issues. I ran the physics toolbox and there didn’t appear to be a change in pressure that strayed far from the outside pressure. However, when it came to both the amp and the subwoofer, which they said they tested they couldn’t find an issue and unless I paid for a new amp or sub there was nothing they could do which I refused since the car is 2 months old and it’s a lease, so I’ll try to figure something else out cause I’m pretty sure that is the issue. I do seem to be one of those people that has a high sensitivity to low frequencies I was just never in any car that ever bothered me before nor did I imagine that this was some sort of possible issue- that a car would randomly emit a low frequency. But we’ll see.

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