Howling/grinding noise
 

Over the winter I had an ABS sensor go bad. Also started hearing a grinding noise I figured was related to the bearing. Replaced the right front hub, ABS back to normal, noise was still there. Replaced the left front hub, noise still there. And its getting worse, very loud at freeway speeds. It certainly sounds like a bad bearing, especially when coming to a stop. Could it be a rear bearing? It sound like its from the front though. It may help to mention that I have either a bad front right strut, or strut mount. But I can't see how this could be related.

Anything else I should be looking at?

This may be stating the obvious Doc, but have you checked the brakes? If the front pads are down to the wear indicator/noise maker gadgets you'll get a grinding noise. Also check the tires all the way around, a cupped tread or a tire with a broken belt can create quite a racket.

Since you have a failing strut, its leading me to think that you have a tire causing the noise, but a check of the rear bearings isn't a bad idea.

What about when turning? is more noticeable in any direction? Might be a CV Axle or a worn engine mount.

Thanks guys!

Thanks. Should have mentioned that brake pads are fairly new, I put them on in spring. Rotors have been on for some time. I've never heard rotors make a noise like this, but I'm open to looking at anything. I'd just hate to start throwing money at it.

I thought about the tires. I've rotated them, no difference.

No difference in sound when turning. I was wondering about the axle too.

My $0.02 for the engine mounts...

might be in the diff which is inside trans. also could be tires if the tread is choppy

OK, you guys gotta help me understand how an engine mount can make a noise that increases with RPMs.

If there´s not insulation or absorbing material between the car frame and the engine, the residual vibrations made by the engine is being transmited to the entire car. If you have more RPMs, more vibration/grinding noise you will have. If the mounts are broken, might exists an excentrical movement of the engine that in some cases can be in contact with the frame or car body. Again, more RPMs, more vibration/grinding noise. Try to open your hood, and see the rocking movement of your engine, and another person pressing gas inside. Perform this at N. Is normal if this move slight, but if moves a lot, you could have this issue. I´m not a college professor, but in my own experience I might tell you this. However, I would like that your issue is not related to the engine mounts. Is a PITA replace these.

OK, so I too am having a howling noise from the front end. Started on Friday & I think it got progressively worse as the day went on.
So yesterday I jacked the whole front end up. Swear, from the driver's seat, it sounds like the tire rubbing on the inner plastic wheel well, but nothing rubbing.
When in N it doesn't make a sound, except for engine noise. Not so much in R either, but I click it into D and there is this low pitch growl. I cannot tell where it's coming from, but sounds a bit louder on the Driver's side than the Passengers.
Doesn't matter if the wheels are turned one direction or another or not, or really any variables like that, but it is tire rotation related. The faster the tires spin, the louder the noise. The 1 thing I didn't do, but I'm gonna this morning is try it with either wheel, keeping one from spinning, & see if I can narrow it to 1 side or the other.
It sounds like a bad bearing, not wheel bearing, but like it's coming from the tranny. Car has been shifting fine & I regularly service the gear box, every 30K. 127K on her now.
Doc, did ya ever figure anything out? I'd appreciate any thoughts from anybody.

Anything new on this? My 2008 just started a similar noise - more from the front passenger side. I thought the tires may be wearing, but in checking the tread depth, I'm a long way from changing the tires. When accelerating, it sounds like I've got mudders on the front! Thanks!

Rich