2003 Alero - loud humming sound at 40 MPH +

Hello,

Our car is a 2003 2.2L 4 Door. 132,000 miles.

About 3 days ago it started doing this thing where once we hit somewhere between 30-40 mph, it started making a low pitch humming sound. At 40 MPH+ it is very loud. To me it sounds like an airplane, I don't know how else to explain it. There is no shaking, though sometimes I can almost feel the vibration from the humming at my feet. My husband says that the higher the RPM's, the louder and slightly higher pitched the sound is. If we go below 30 MPH it stops.

We were a little late on our oil change and I assumed that was it, but got it changed today and it's still doing it. Other than that, about 2 and a half weeks ago, our rear driver side tire went flat. My husband was in the middle of no where on the way home from work so he used Slime and that fixed it (never went to get it repaired because we didn't have the time and it didn't go flat again).

Could it be that the tires are not balanced corrently because of that, and it is causing the humming?

Also, this may be completely unrelated but: The only other problem we have had/still have with the car is that about 2 years ago we drove from Texas to Nevada, and at one of our stops the coolant dumped out (did not overheat/no other issues). Took it to 2 different shops and they couldn't find anything wrong with it. Drove fine until 6 months ago driving from Nevada to New Mexico, it did it again, but this time it also overheated. The mechanic said it was the water pump. Replacing the water pump (which is expensive!) did not fix it, so without consulting us they also changed the thermostat. Charged us for both, told us it was fixed, and about 2 month ago it did it again, but did not overheat/no other issues again. Hasn't done it since...seems it only happens on long drives. Anyway, I don't think it's related, but I thought I'd mention it.

Any help would be greatly appreciated. Sorry I went into such detail!

Sounds like a wheel bearing is failing, except for the higher-rpm part. If it's a wheel bearing, the noise should be related to vehicle speed, not engine rpm. Get it up to 50mph, when it's making the noise shift into neutral. If the noise doesn't change, then it's very likely it's a bearing.

You can check the bearings by jacking up each wheel, grabbing it at 6 and 12 o'clock positions, and trying to push/pull on the wheel. There should be no play in the bearing. Since it's front-wheel drive, it's easy to also rotate the rear wheel when it's off the ground, and see if there's any grinding/binding. It's sometimes hard to figure out, just from listening, which bearing may the bad one. However, the front ones usually go out sooner/more often, and at 137K miles you are overdue for this common failure. If you find it's one of the front bearings, I'd recommend replacing both left and right at same time. if you're DIY types, this is a job that can be done in the driveway and save $$$. Check out:

http://www.automotiveforums.com/vbulletin/showthread.php?t=762786&highlight=hub+assembly

Hope this helps.

Thank you very much! That was very informative. In my opinion it gets slightly louder/higher pitched with speed as well, but I only drive it in town. My husband drives it on the highway mostly so I just went with his wording. We will hopefully have this fixed in the next couple of days so I will make sure to come back and update.

Thanks again!

So for an update -

It was a wheel bearing, the front left to be exact. Figured out which one it was on my own; the tire only moved slightly when I grabbed it at 6 and 12 but the others didn't move at all. Bought the part and since we don't have any tools on hand, the mechanic at my husband's job replaced it for us.

No more airplane noise & we saved money by not having to take it in :)

Thanks again skeeter!

Glad it helped and thanks for the update.

Hello,

Our car is a 2003 2.2L 4 Door. 132,000 miles.

About 3 days ago it started doing this thing where once we hit somewhere between 30-40 mph, it started making a low pitch humming sound. At 40 MPH+ it is very loud. To me it sounds like an airplane, I don't know how else to explain it. There is no shaking, though sometimes I can almost feel the vibration from the humming at my feet. My husband says that the higher the RPM's, the louder and slightly higher pitched the sound is. If we go below 30 MPH it stops.

We were a little late on our oil change and I assumed that was it, but got it changed today and it's still doing it. Other than that, about 2 and a half weeks ago, our rear driver side tire went flat. My husband was in the middle of no where on the way home from work so he used Slime and that fixed it (never went to get it repaired because we didn't have the time and it didn't go flat again).

Could it be that the tires are not balanced corrently because of that, and it is causing the humming?

Also, this may be completely unrelated but: The only other problem we have had/still have with the car is that about 2 years ago we drove from Texas to Nevada, and at one of our stops the coolant dumped out (did not overheat/no other issues). Took it to 2 different shops and they couldn't find anything wrong with it. Drove fine until 6 months ago driving from Nevada to New Mexico, it did it again, but this time it also overheated. The mechanic said it was the water pump. Replacing the water pump (which is expensive!) did not fix it, so without consulting us they also changed the thermostat. Charged us for both, told us it was fixed, and about 2 month ago it did it again, but did not overheat/no other issues again. Hasn't done it since...seems it only happens on long drives. Anyway, I don't think it's related, but I thought I'd mention it.

Any help would be greatly appreciated. Sorry I went into such detail!

Glad you were able to get your car fixed. It was only a matter of time that your idiot lights I call them in the dash would have come on. That is typically the tale tell sign that one of the bearings have died. As for the overheating, my 2000 that has around 185,000 miles on it sometimes acts like it wants to overheat, too. Go to the dealer's parts department and ask them for some of the coolant leak stop tablets that GM sells and crush them up and drop it into the coolant recovery/add tank on your passenger side fenderwell. That stuff is magic! Will stop any slight leak and for some reason, I assume that is associated in someway with those magic pills, mine doesn't run as hot anymore. Mine would try and overheat if I set in a drive thru or at a light too long. Doesn't do it anymore. Good luck. :smile:

until they block a water jacket.....

lol but until then its a good fix. :)

hey all,
having this humming prob;em as well... my first impression was the bearing, but after a couple days the 3 idiot lights came on and the brakes were acting funny. so happy we have forums and threads to use and help eachother out. thanks for posting AND updating. i will do the same.
oh btw it's a 2002 Alero GLS 4dr we have only had it a month.... you'd think with all the similar problems over 10 years with the Alero that ANYONE can access through a simple search on the internet that at the very least the dealer we got the car from (used...someone traded it in...we bought it) would have known about the issues and checked more thouroughly.

Are you kidding me? These small used car dealerships, sell you the car, in this case a 10 year old car, and you are lucky to get a 30 day warranty from them......as a rule, they tend to put money aside from the sale for possible repairs.....they know if something is wrong with the car.....a tech probably did a safety inspection, and wrote the possible problems with the car......the dealership hopes you don't find any problem in that 30 days, and then they can pocket the money......

Anyone buying a used car from a dealership or private party, should take the car to a trusted garage and give them one hour's labor time to do a safety inspection......then you go back and take advantage of that 30 day warranty.....

From the sound of it, it probably is a bearing. You have ABS (Anti-lock Braking System) on your car, and sometimes when bearings go bad, it will mess with the sensor. There is a gear looking wheel inside your bearing assembly or around the axle, and also the ABS sensor itself which is a magnet. The gear rotates with your tire as you drive and each nub on the gear goes past the magnet with a very low clearance between the two. Basically when your bearing goes bad, it messes up the clearance and the wheel will either be too far away or not rotating straight and it will turn your ABS light, Service Vehicle Soon light, and Traction Control light on. Take it to a shop, ask them to check your wheel bearings and to drive it. They should be able to figure it out.