road surface related helicopter type "bass" noise starting at 35mph

[ningduo]

Anyone experience helicopter type "bass" noise starting at 35mph? It sounds like when you set the bass in high，those air pushing in your ears..... I am sure all the windows including the sunroof was fully closed. and it was related to the road surface, I barely hear/feel the noise when I was driving on the new painted pavement. Unfortunately most of the dry pavement here in Alaska are not perfect, a little rough. When I was driving on these 40mph limit "everyday surface". It was really really annoying. I took the truck to the dealer and they told me they tested drive another 4runner which made the same noise (yes, they admit my truck has some kind of noise) they said it is all normal.

Anyone here on this forum lives in Anchorage and experience the same thing?
I did post some before when I thought it was some kind of the vibration. I hope it is just a tire/road problem(they are oem stock bridgestone)

 

[Cracka]

I think I know what you are describing. In my experience it is due to a single window being partially open. Usually a front window, making it related to air pressure. When this happens I open a rear and it resolves. It can be deafening. But you said you were sure the windows were closed so maybe not with the 5th gens.

I get it in my Megacab, 4th gen, and have been in a mini-van when it occured.

 

[prestone818]

i know u said u think the windows were up but that certainly is what closest resembles a helicopter noise. sometime road conditions are a little off and the sound from the tires on the road will make you think something is wrong. but that will not be on every road...

 

[ningduo]

I saw a lot of 5th gen 4runners on the road everyday, anyone in Anchorage on this forum experienced the same thing while "everyday normal" driving?

 

[Fuzzylogic]

I think I know what you are describing. In my experience it is due to a single window being partially open. Usually a front window, making it related to air pressure. When this happens I open a rear and it resolves. It can be deafening. But you said you were sure the windows were closed so maybe not with the 5th gens.

I get it in my Megacab, 4th gen, and have been in a mini-van when it occured.

Mine does it when the rear windows (only) are down. It's actually quite spectacular! It makes you feel like your brain is inside a drum being beaten by Alex Van Halen.:drummer:

I believe it is caused when the open window creates negative pressure in the cabin, which pulls in air, quickly pressurizing the cabin. It then equalizes and repeats (hence the "thumping" and ear popping).

My Suburban did the same thing. If you open the rear window slightly, it goes away because it provides an open pathway for air to flow.

It's entertaining when I do this with people in the truck. I get a lot of "WTF is that?"