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Humming sound from Scion TC

I have a 2006 Scion TC. It started making a humming sound about a week ago. I have to drive about 30 mph before the noise is noticeable. The noise is fairly low pitched, but the frequency and volume increase the faster I drive. I can take the car out of gear and that doesn’t change the sound at all. Does anyone have any idea what this might be or what it might cost to fix it? I can recognize that something is wrong because the noise is new, but a mechanic listening to the car might not realize anything is abnormal.

My first guess would be a bad wheel bearing. There are other possibilities also, but the possibility of losing a wheel at high speed due to a seized wheel bearing should send you to the mechanic quickly in order to determine exactly what is going on.

Finally, something I know something about!

How worn are the tires?

I can speak from personal experience (I owne a 2005 tC with 116,000 miles) in saying that when the tires start to get near the wear bars it’ll manifest itself as high road noise. I love my tC, but isolation from road noise is not what it is in most cars. It sounds just like a wheel bearing going.

I just mounted my 4th set of tires, and I know this sound.

Hmmmm…Interesting, MB.

You are probably correct, given your specific experience with the vehicle.

OP–How many miles are on that set of tires?

I’ll check the tires, but I think they are good shape. They only have about 20K or so on them. Unfortunately, it’s probably the wheel bearing.

Thanks for your advice.

Don’t discount the tire theory too quickly. Some brands/models of tire can have significant wear after only 20k miles. And, with some tire models, road noise can increase dramatically once the tread is half-worn.

The tC comes stock with Z rated tires, and while they do handle better they also wear far faster. Typically mine start getting noisier at about your mileage.

When my first set started getting low I checked my bearings. I too thoght I must need new ones. I didn’t. The new tires made all the difference.

I realize that you may actually have a failing bearing, stuff happens, but don’t discount my experiences too quickly.