Video will be attached below. Please forgive my very noisy cabin, iPhone picks up every single sound possible and roads here are crap. In the video, you will see and hear me accel/decel (no brake, just foot off gas) between around 3500-4000 rpms.

https://youtube.com/shorts/91Kc8JfiQpg?si=xoJ7r6ke5fAQCKEk


To me, noise sounds like someone put in the worlds worst CAI - deep/throaty, but non-acura typical revving/accel noise that you would expect from a much older gas/diesel vehicle or really crappy V8.

Some things I’ve noticed:

-Cannot seem to replicate while vehicle is not moving (in park, or in drive w/brakes engaged).

-Noise is almost un-noticeable when going downhill, however I haven’t taken it past 3000rpm downhill

-Noise is considerably less noticeable when going uphill - even more so on winding roads.

-Noise is most apparent on flatter roads while doing above 1500rpm, very loud at 2800rpm+.

-Noise disappears shortly after higher gear change (2nd to 3rd, 3rd to 4th, etc) while RPMs drop sharply, and comes right back as RPMs climb.

-Not intake hose related. Replaced it with new mounts (more info below), was cracking and as far as I’m aware completely original rubber unless prev owner changed it before 50k mi.

-No codes and no noticeable loss in power.



Based on these symptoms, I’ve deduced/assumed:

-Not wheel bearing/suspension related

-*Hopefully* not torque converter related, as unable to replicate while not moving - seems to be physical acceleration related rather than RPM related

-Not an intake / exhaust leak?? - or not enough of one to trip the sensors.


Recent work done:

-Timing belt kit done ~800 miles ago by Acura dealership. Car felt and sounded the best it has since taking ownership at 50k mi.

-Replaced passenger side engine mount and top transmission mounts myself ~200 miles ago (taking it in to do front, lower and rear mounts, small arms can’t reach).

What could be a big hint:

Noise started not even a mile after replacing the mounts. This has made me lean towards the issue maybe introducing an imbalance between the mounts, as I’m pretty sure the front, rear, and lower mounts are completely shot. This could explain why the noise is apparent while going uphill but seems to falter when cornering/near constant turning (weight is shifting to brand new mounts). If not an imbalance, perhaps a slight misalignment between the engine and one or more of the exhaust hardware?

However, I’m definitely no mechanic and would love any thoughts/input as to what this may be before the dealership steals another $275 from me for diag by someone that knows what it should sound like…

 

check all the bolts you undid for the trans and side mount and make sure they are tight and nothing is rubbing.

 

Will do

 

Just finished double checking the work, all bolts are tightened to spec with no signs of movement (bay is filthy, would be quite easy to see scrape marks), no glaring points of contact related to the mounts.

however, did notice the resonator chamber is a bit loose, not sure if this is normal or if it’s usually tight in place. Also seems to be making direct contact with the long metal screw/piece that holds the battery housing in place.


On the other side of the battery housing, there is a very small point of contact to the airbox. I tried reseating the airbox in hopes to correct positioning to no avail, contact point still there. Will be attached in next comment.

 

here is video showing airbox to battery housing contact