I have a low(bass) hum when driving over 20mph or so, worst at between 35 and 45. Its speed related, not engine RPM related. Same when going straight or turning right, Turning hard left (like around a traffic circle) the noise goes away.

Figuring its a wheel bearing but how to tell which one?

The car is an 07 Fit Sport with 63K on it. Box stock. I recently bought it used

Suggestions? A dealer says its the tires (they're Mastercraft Advantage, plenty of tread on them) but that wouldn't explain why it goes away when turning left.

Suggestions...please?

 

Probably just tire/tread noise.

Are you making left turns at 35-45 mph? Even if you are, the tire noise does change when you turn the steering wheel. The wheel doesn't just turn, but the camber changes as well, so the tire's contact patch is affected while turning.

 

Could be the tread but you can exchange the wheel side to side and see if the hum changes the turn; and it can be wheel bearing and it can be due to a universal joint wearing out.

 

Okay, I'll try swapping the tires from side to side and see. The noise is pretty loud, and they are el cheapo tires though. I don't usually take sharp turns that fast, but I can do a traffic circle at over 20mph (loud enough to hear the noise if its present). Otoh the Fit does crazy performance on the skid pad

 

if the noise goes away when you make left turns, that means your left wheel bearing is bad

 

Thanks, for all the stuff I've worked on in my cars I've only ever had to replace a wheel bearing once. It had seized up, when I took the wheel off and put the wrench on the cap nut on the CV the end of the CV fell off and the ball bearings rolled out, they had tempered to a nice straw color.

 

yeah. i already replaced a fit wheel bearing. im pretty sure i have 2 bad wheel bearings right now

 

I agree. This happened to me not too long ago on my balding Kumho Ecsta SPTs (they were worn down flush with the wear bars) and I initially thought it was a wheel bearing gone bad.

These kinds of noises are very hard to properly diagnose, and I would suggest swapping the tires out for another set and driving the car in the same manner, just so you could rule them out as the cause.

The best way to check is to have a trusted mechanic look over them. The guys at my home-base garage say that a bad wheel bearing will make itself known really early, at just 10 mph.

Just sharin' my input/experience, hope this helped

 

Swapped the front tires from side to side, no change in sound, so I'm figuring its the bearing. Since the sound virtually goes a way when turning left I'm going with solbrothers advice and replacing the left side. Pretty sure I'll just order a complete hub, easier to swap out easier is more betterer.