Loud Oscillating Noise from Engine Bay at Speed - 2004 MT

For the 4 years I've owned the car, the cockpit has been on the louder side of the cars I've driven. I figured cause it was a cheap car, it just had poor sound deadening and what I has hearing was road noise. Over the years though, I kept having to raise the radio volume to hear the music as the noise has grown increasingly louder. Within the past year, it's gotten so loud that passengers are complaining so I figure something's wrong.

Symptoms:
- Loud noise from engine bay (sounds like front right). No noise when stopped, gets much louder with wheel speed so I doubt it's engine related
- Has "dead zones" where the sound goes almost completely away (~80km/h and 130km/h)
- Making gradual turns seems to either worsen or eliminate the sound (IIRC turning right makes the sound go away, turning left makes it really bad) so that makes me think it's not something wheel/tire related
- Sound is very low and deep and seems to oscillate at about 5-10Hz (varies with speed, sounds something like an imbalanced wheel)
- Lots of vibrations proportional to the sound. All the change sitting in the car rattles like heck and parts of the dash can be felt vibrating.

What I've Tried:
- I hoisted the car up, ran it up to third gear. Still makes the noise. So probably not tires.
- Took the brakes and rotors off and wiggled the hubs. Right one had a fair bit of play in it so I pressed in a new bearing but it still sounds just as bad if not worse. Left one had no noticeable play.

I'm going to double check the balancing on the wheels tomorrow but I have my doubts that's the problem. Is there anything I'm missing here? Could it be the left bearing? A cv shaft? The tranny? How can I check?

It's a 2004 Aveo, 5-spd Manual, ~135000kms, stock drive train

From my experience any kind of shaking, especially in the steering wheel is tires out of balance, or they are worn funky, had one tire cause all kinds of trouble, but it was out of round. How are the tires wearing? Any cupping or crowning of the tread contact patch? This can cause all sort of nasty noises and shaking. FYI

Just checked the balance on the wheels. They were a little out so I re-balanced them. Didn't help at all, noise is still as loud as ever.

Tire wear doesn't appear to have any abnormalities. And as I said before, it still made the noise even with the wheels off the ground and the car stationary. So I'm convinced it has something to do with the drive train.

I guess I'll try replacing wheel bearings and axles until the sound (hopefully) goes away.

Any tips on checking for a bad cv axle?

See if the boots look good, I know they can tear and let all the grease out, or maybe a bent one?

Thanks for the input.

Checked the shafts, all 4 rubbers look good. No grease around them. Shafts don't look noticeably bent.

Quote:

---

Originally Posted by RGoessl

...Took the brakes and rotors off and wiggled the hubs. Right one had a fair bit of play in it so I pressed in a new bearing but it still sounds just as bad if not worse. Left one had no noticeable play.
...

---

I had a bad wheel bearing on one side that gradually got worse over time. Gave a fairly loud whup-whup (washing machine) sound at lower speeds and increased when turning to one side. However, there was no vibration inside, and there was also no movement when shaking the wheel. In fact, when I did replace it, I could only feel a VERY slight clicking of the hub in the knuckle. I was really surprised to find out that this tiny bit of bearing movement could cause that much noise, which was all eliminated when the bearing was replaced.

So, I'm wondering about that 'fair bit of play' you felt on the right side. Are you certain it was the hub wobbling inside the knuckle on a (really) bad bearing? Did you check the amount of play after the bearing was replaced?

Quote:

---

Originally Posted by avguy

So, I'm wondering about that 'fair bit of play' you felt on the right side. Are you certain it was the hub wobbling inside the knuckle on a (really) bad bearing? Did you check the amount of play after the bearing was replaced?

---

It was definitely the hub inside the bearing and it was pretty bad, I'd say about 1-2mm of play at the end of the hub. Once I replaced the bearing the play was gone. I thought for sure that was going to fix the noise but it didn't even make a difference.

The noise is just like what you are describing, maybe the other bearing is bad too - there was a slight clicking when wiggling the left hub.

Wheel hub/bearing

Since you have the equipment and the know-how, definitely replace the other bearing before considering doing anything else.

Quote:

---

Originally Posted by avguy

Since you have the equipment and the know-how, definitely replace the other bearing before considering doing anything else.

---

I'll give it a try this weekend. Let you guys know how it goes.

Turns out it was the left wheel bearing.

Jacked the car up, one wheel at a time. Ran each side to ~80km/h. Left side was much, much louder. Changed the left wheel bearing, car runs and sounds like new now!

Thanks for the help.