I've started hearing a noise. Yeah, that's how a lot of these threads start off ;-) But I think I have it narrowed down, just looking for help to confirm one or the other here.
- Heard at highway speeds, especially 40-70mph (above that I think the wind noise hides it)
- Pretty certain it's front end, and I think left side
- Not related to engine speed
- More high pitched, and sharper than tire noise
- Some mild/moderate shaking when braking from highway speeds, depending on the day

Now, to tell if it's a dragging caliper or a wheel bearing, I've tried jacking up and pulling on the wheels on the right (supposed good) and left (supposed bad). I can't really tell a difference in play. I know to not pull left/right, but is it up/down, or in/out?
I've got an IR thermometer that I put to good use. After about 30 minutes on the hwy around 80mph... left rotor reads about 190-200F. right rotor around 140-160F. Brake pads and calipers both around 140 either side.

Those temps are my biggest clue to think about wheel bearing. Anyone dis/agree? Other things to check for? I can pick the bearing up from a local dealer for $195 and replace it this weekend, just need to get a breaker bar and socket for the axle nut. That's my weekend plan unless you all tell me otherwise!

 

Ah, right -- I did inspect the front calipers. Right side slides nice and easy, left side just a little resistance. My Subaru had a really frozen slide pin. This isn't anything like that, but does actually take effort to slide vs the other side.
I wouldn't think I'd feel something that mild? But maybe when the wheels spin at 70mph...

And, some pictures of my car (for bribery, since I never posted any in my Newbie Thread!)
Mine is the 2009; the 1st generation is a nice, clean parking lot stranger in the same color. Makes me smile

 

Man, those are some clear head light covers on that V35. Those that I see usually have some serious U.V. fogging.

I can't provide a definitive answer for you but I will say a caliper rebuild is cheaper than a wheel bearing replacement.

 

They really are clear! More incentive to polish mine.
when you say rebuild caliper, I assume you mean the slide pins, not the piston/boots.
What parts there should I replace vs clean? Maybe I haven't looked enough, but didn't see part #s around, just a comment someone went to RockAuto for them.

 

Front caliper rebuild kit (for the pistons) CARLSON 15340

Pin Boot Kit CARLSON 16185

slide Pin Kit CARLSON 14138

Caliper Hardware (fits around top and bottom of brake pads) CARLSON 13487

^^
all available at rock auto, jsut punch in the make year and model of your car...don't forget google a 5% discount coupon

 

For the front wheels, you need to grasp them at 12 o'clock and 6 o'clock to check for play in the hub bearing. That said, a failing hub bearing will start making noise before you notice any play.

I just had a hub replaced under warranty. It was noisy at speeds greater than 40 MPH. No play was found.