a few usual suspects:
brake calipers/pads/rotors dragging/binding
cv joints (half shaft as Honda calls it)
wheel bearings

last two might be a little premature for age/mileage, but depending on things could be possible

 

Any ideas for further tests, or how to check, or what might be more likely, especially given the fact that it only exhibits itself for the first two or three sharp turns after being "cold."

 

doubt it’s directly related to the noises, but on the brake fluid - seems like you only did half the job if you didn’t flush out the old fluid in the lines all the way to the bleed ports on each wheel.

regarding The noise, are you comfortable with taking down your brakes to the rotors, removing and inspecting the pads, associated spring clips, calipers, caliper bracket, etc ?
When is last time you had brake work done, and what was it? I assume you have had pads replaced sometime before 100k?

 

As far as the last time the brakes have been done, it was done by the dealership that I purchased the vehicle at about ~90k miles in August of last year. Listed as replace pads and turn rotors. I have always noticed quite a fair amount of brake dust, though. Tires are brown by a week or two after a nice car wash.

I know I didn't do a full brake flush, as I didn't have a helper to bleed them.

 

Here is video of the issue.

At about 0:36 you can hear it the best, and even see the steering wheel shake. Also, it does do it on both left and right turns.

 

Seems to me like the noise appears while driving with the steering wheel turned fully. Do you hear/feel the rumble in both directions? I would test fully turning the wheel in one direction then slowly accelerating in an empty parking lot to see if you can reproduce. Bad cv axles are known to cause noise in these types of scenarios

 

what size tires, are they stock?

Is this happening when you are braking?

Does it ever happen without applying brakes (or go away if releasing the brakes?)

I would definitely suggest pulling the front tires off and inspecting the rotors, and pulling the calipers off, and inspecting the pads and checking for the (proper) assembly of the pads, caliper pins, shims/brackets. This is relatively easy to do to rule out brake issues.

 

what size tires, are they stock?

Is this happening when you are braking?

Does it ever happen without applying brakes (or go away if releasing the brakes?)

I would definitely suggest pulling the front tires off and inspecting the rotors, and pulling the calipers off, and inspecting the pads and checking for the (proper) assembly of the pads, caliper pins, shims/brackets. This is relatively easy to do to rule out brake issues.

Tires are 245/60R18, and seem like that would be OEM size. They still have > 7/32" tread, so probably not original, but I'm not sure. They're Kumho.

It specifically happens when I'm not braking, stops when braking or decelerating.

I'm not ruling out that it could be a brake issue, but not quite sure how/why the brakes would cause that symptom?

 

If it hasn’t already been done, I would suggest some initial visual inspections of the brake pads, rotors, calipers, as well as the cv joints (inspect inner an outer boots for cracking/wear, and any evidence of seepage or slinging of grease, etc.). Also, would be good to inspect various suspension components (joints, bushings, etc), but not sure that would cause what you are showing in the video
If none of these things turn anything obvious up, it may be time to bite the bullet and at least have the dealer or another reputable shop give it a diagnosis.

 

Boots and everything seemed OK, visually. I got that other document you sent me for inspecting the brakes, but will have to buy that tool that it calls for, first. Haven't brought it to the shop, yet, because of the fact it only happens after it's sat for a while, so trying to get good video and such, since it would be hard for them to reproduce. Don't want to pay a diagnostic fee, and them not be able to actually reproduce and find the issue. And, wanted to make sure it wasn't something I did wrong with the recent maintenance.

 

Well good news is that if it’s bearings or cv joints, it will likely get worse over time to the point where it will be easier for a shop to reproduce reliably
so just drive it

 

I realize that the AWD systems are different, but when I had my Honda Element, the exact same issue would happen when it was time to do a fluid change on the AWD system. Once the fluid was changed, problem solved. I know Zroger has way more knowledge than I so maybe he can put me in my place…which I am fine with! Has your fluid be changed per the MM?

 

Which fluid? Transmission, Differential, Brake, power steering? That's why in the OP I listed the maintenance I had recently done, in case one was possibly done incorrectly and/or not filled enough. I know I didn't do a full flush of the brake fluid, but only replaced the reservoir fluid (on purpose at the time). Since it happens when I'm not braking, I'm assuming it's not the brake fluid.

I did these maintenances myself, as they wanted $300 for transmission fluid service, $175 for brake fluid service, and $120 for differential fluid service. (Not to mention $625 for spark plugs.)

 

Same on my ‘06 AWD Element.

 

Finally took the truck to a local shop, and they said it wasn't the CV Joints or wheel bearings or anything, but likely the differential. However that shop doesn't work on differentials, and suggested I take it to the dealer.

I dropped it off at the dealer, and they found that the transmission fluid was about a quart low. So, I feel stupid about that, but it was hard to read, and needing to do it hot, really makes it tricky to get down to that dipstick without burning yourself. So, topping off the transmission fluid did solve the major creaks, groans, shaking after a cold start, but, the differential still groans a bit. Looking back at the history of the maintenance on the car, the previous owner had taken it to a shop for differential service in the past, and it had started making a noise. So, he then took it to his dealership where they discovered that the other shop had filled the differential with some sort of "gear oil" instead of Dual Pump II fluid.

At any rate, the major noise issue is resolved, but the shop recommends a new differential be put on, to really complete the job. That would be a used differential with 57,000 miles on it with install for about $1800.

 

Ouch. Such an avoidable issue, that rear diff thing. Probably why the PO dumped the Ridgeline and swore off Hondas. 🤦‍♂️

 

This is why I have a hard time taking my vehicles anywhere to get them worked on. If it says antifreeze on the bottle well that's good enough, they will dump it in, regardless of make. If it says gear oil and they're working on a "differential", they will dump it in. So on, so forth. I've had people argue with me that fluid type doesn't matter before. "It's all the same". Well not really..

Pay for the right stuff from the get go or you will literally pay for it.