Deep Base Type Noise - Tires?

[against_The_Wind]

Significantly reduced engine noise inside the cabin by installing a Dynamat hood liner under the oem hood insulator.
I fabricated longer nylon retainer clips from the oem retainer clips by cutting off the short stem, drilling a hole in the original head and inserting a long nylon retainer.
Dynamat HoodlinerView attachment 422890View attachment 422891View attachment 422892

Very interesting idea Pedro.

I may have to try that. I would have thought that the firewall is where most noise enters the cabin, but I guess the hood transmits a lot of sound to our windshields.

I've been trying think of areas to add foam inside the vehice, such as where the spare tire is and maybe under the first row seats where the floor vent seems to be laying on the metal floor of the vehicle where there are cutouts in the floor carpet. Not sure if any of this will help.

I've never used dynamat before or actually never tried to reduce sound in a car, for that matter, but I'm assuming that stuff is best for this purpose

 

[Pedro504]

Very interesting idea Pedro.

I may have to try that. I would have thought that the firewall is where most noise enters the cabin, but I guess the hood transmits a lot of sound to our windshields.

I thought the same initially, especially with the fact that the firewall has no insulator. It's hard plastic!
The Dynamat hoodliner is made up of an acoustical foam that converts sound waves into heat energy. So there must be a lot of sound waves bouncing around in the engine compartment that the small oem hood insulator cannot mitigate.
I'm very pleased with the Dynamat.

Sound Absorption For Your Vehicles Engine Noise | Hoodliner | Dynamat

Dynamat Hoodliner is specifically built to absorb engine noise from your vehicles engine bay. Maximum noise control for maximum comfort.

www.dynamat.com

 

[Mbrooks420]

I’d skip the foam. I’d go with dynamat, or one of its cheaper competitors, and have the floor done.

 

[peterk9]

I thought the same initially, especially with the fact that the firewall has no insulator. It's hard plastic!
The Dynamat hoodliner is made up of an acoustical foam that converts sound waves into heat energy. So there must be a lot of sound waves bouncing around in the engine compartment that the small oem hood insulator cannot mitigate.
I'm very pleased with the Dynamat.

I believe a member here mentioned that the 2021 Platinum has the 'fake engine noise'. is that true?

Peter

 

[Pedro504]

I believe a member here mentioned that the 2021 Platinum has the 'fake engine noise'. is that true?

Peter

I don't know if the Platinum has the 'fake engine noise'.

 

[Dale5403]

I don't know if the Platinum has the 'fake engine noise'.

Easy way to find out. Put it in sport made and step on it a bit. It's very noticeable on my ST.

 

[Turdle]

Helmholtz resonance - Wikipedia

en.wikipedia.org

 

[Pedro504]

Easy way to find out. Put it in sport made and step on it a bit. It's very noticeable on my ST.

Well I did as you suggested and in normal and sport mode it sounds the same under moderate-high acceleration. I'm of the opinion that my Platinum built in early Sept 2021 does not have hardware or software generated engine sound enhancement.

 

[Dale5403]

Well I did as you suggested and in normal and sport mode it sounds the same under moderate-high acceleration. I'm of the opinion that my Platinum built in early Sept 2021 does not have hardware or software generated engine sound enhancement.

It would appear that your Platinum doesn't have it then. Like I said it is very noticeable on my St when switching from normal to sport. Thanks for checking and letting us know.

 

[Sea_Ray]

My 2020 AWD XLT
The sound described as being in a ball and buffeting was spot on.... I will say though it happened while sitting at a stop light too. I would turn the radio full volume trying to blow the dam thing up. It seemed like it was coming from rear speakers.

I did take it in, rotating the tires and shaking the **** out of exhaust did solve the problem long enough for the trans shifting and piss poor response when changing lanes on expressway got to point were I dumped that POS with 10,000 miles.

 

[against_The_Wind]

My 2020 AWD XLT
The sound described as being in a ball and buffeting was spot on.... I will say though it happened while sitting at a stop light too. I would turn the radio full volume trying to blow the dam thing up. It seemed like it was coming from rear speakers.

I did take it in, rotating the tires and shaking the **** out of exhaust did solve the problem long enough for the trans shifting and piss poor response when changing lanes on expressway got to point were I dumped that POS with 10,000 miles.

I have started to think that the deep noise I am hearing, when NOT hitting bumps in related to the exhaust.

 

[Sea_Ray]

I have started to think that the deep noise I am hearing, when NOT hitting bumps in related to the exhaust.

I would here it while sitting in the garage waiting for the trans pump to build up enough pressure to engage wheels.

 

[peterk9]

I would here it while sitting in the garage waiting for the trans pump to build up enough pressure to engage wheels.

Haven't heard of waiting for that before. You should be able to start and go right away.

Peter

 

[against_The_Wind]

Tonight, I was driving and when it was safe to do so, I put the car in neutral once I was around 40mph and then allowed myself to come to a stop as I normally would.

My theory is that the deep bass sound were experiencing when slowing down at these speeds is resonating from the exhaust when the car downshifts as we slow down.

Sure enough the car was quiet as can be as I slowed down, since there was no downshifting.

I may try it again to be sure, but I'm pretty certain that may be the issue.

There is still the other bass sound from hitting small pavement imperfections that this is not related to.

 

[Sea_Ray]

Haven't heard of waiting for that before. You should be able to start and go right away.

Peter

ya think!

 

[peterk9]

ya think!

Yup. Do it all the time.

 

[Pedro504]

Tonight, I was driving and when it was safe to do so, I put the car in neutral once I was around 40mph and then allowed myself to come to a stop as I normally would.

My theory is that the deep bass sound were experiencing when slowing down at these speeds is resonating from the exhaust when the car downshifts as we slow down.

Sure enough the car was quiet as can be as I slowed down, since there was no downshifting.

I may try it again to be sure, but I'm pretty certain that may be the issue.

There is still the other bass sound from hitting small pavement imperfections that this is not related to.

aTW (against_The_Wind) - I performed your test today on my 2021 Platinum in Normal drive mode, Radio off, Climate control on auto (low).

Test Case 1:
Cruising at 40mph on a super smooth roadway, I let off the throttle and coast down to 10mph never touching the brake pedal. Immediately the characteristic deep base sound resonates throughout the cabin changing amplitude multiple times as the vehicle slowes down.

Around the block to try it again but this time shifting into neutral simultaneous with deceleration.

Test Case 2:
Cruising again at 40mph on the exact same super smooth roadway, I again take my foot off the throttle but this time immediately shift into neutral and coast down to 10 mph never touching the brake pedal. What happens next leaves me speechless. The cabin is so quiet I can hear my heart beat, seriously, no noise whatsoever, no deep base sound, nothing, it's quiet. What I expect from a $60k vehicle.

One more time around the block to repeat the Test Case 1 and I experience the same noisy results.

Obviously we can't drive like that. What's our next steps forum members?

 

[against_The_Wind]

aTW (against_The_Wind) - I performed your test today on my 2021 Platinum in Normal drive mode, Radio off, Climate control on auto (low).

Test Case 1:
Cruising at 40mph on a super smooth roadway, I let off the throttle and coast down to 10mph never touching the brake pedal. Immediately the characteristic deep base sound resonates throughout the cabin changing amplitude multiple times as the vehicle slowes down.

Around the block to try it again but this time shifting into neutral simultaneous with deceleration.

Test Case 2:
Cruising again at 40mph on the exact same super smooth roadway, I again take my foot off the throttle but this time immediately shift into neutral and coast down to 10 mph never touching the brake pedal. What happens next leaves me speechless. The cabin is so quiet I can hear my heart beat, seriously, no noise whatsoever, no deep base sound, nothing, it's quiet. What I expect from a $60k vehicle.

One more time around the block to repeat the Test Case 1 and I experience the same noisy results.

Obviously we can't drive like that. What's our next steps forum members?

Wow,

glad to hear someone else duplicated my results. I have no idea what the recourse could be for this.

I also think back to how Ford had all the issues with exhaust entering the cabin with the previous gen Explorers and I wonder if they did something unorthodox with the exhaust to mitigate that and created this problem.

I will say that tonight I was out driving again and I don't always have the bass sound when decelerating, which is odd, and when it does do it, its one I am decelerating to almost a complete stop.

Pedro504, do you get bass noise the entire time going from 40mph to almost a complete stop?

 

[Pedro504]

Wow,

glad to hear someone else duplicated my results. I have no idea what the recourse could be for this.

I also think back to how Ford had all the issues with exhaust entering the cabin with the previous gen Explorers and I wonder if they did something unorthodox with the exhaust to mitigate that and created this problem.

I will say that tonight I was out driving again and I don't always have the bass sound when decelerating, which is odd, and when it does do it, its one I am decelerating to almost a complete stop.

Pedro504, do you get bass noise the entire time going from 40mph to almost a complete stop?

While decelerating or coasting in gear from 40mph to 10mph the deep base noise changes in loudness and tone.
Becasue there is absolutely no deep base noise when the vehicle is coasting down from 40mph in neutral and the engine is basically idling it's difficutlt to determine if the source is exclusively the transmission or the engine/turbo/exhaust.
I'm leaning toward engine/turbo/exhaust.

 

[Sgt1411]

While decelerating or coasting in gear from 40mph to 10mph the deep base noise changes in loudness and tone.
Becasue there is absolutely no deep base noise when the vehicle is coasting down from 40mph in neutral and the engine is basically idling it's difficutlt to determine if the source is exclusively the transmission or the engine/turbo/exhaust.
I'm leaning toward engine/turbo/exhaust.

It would be interesting to know what your engine compartment temps are now that you have acoustic insulation that converts sound to heat. That temp is closely engineered that's why the PIU has no sound insulation pad from the factory. In the winter probably not an issue but in summer might be over the limit.

Hopefully your OK.