Mustang65

CAR: 2006 Cobalt SS 2.4L

Problem:

Whenever you accelerate you hear this strange thumping sound. You hear it in different tones at all speeds. It's a strange "whump" sound. It reminds me of driving a lifted jeep with super swampers on it.

My first though was that the tires were worn out and needed to be changed. Some idiots at a garage in Lousianna changed only the back two at 30K when she had a back flat, instead of changing all four. So, I rotated the tires, in hoped that the sound would move or change and I would know for sure where it was comming from. No joy. Stayed the same.

I did notice that it's worse and at slower speeds and I can feel a slight vibration through the pedals. I think that the front rotors may need to be turned.

Has anyone else had a similar issue?????

XM15

If the rotors needed to be turned you would feel a noticable pulsing when you hit the brakes.

Coblasts

Wheel bearing would be my first thought !

XM15

Wouldn't a bad bearing be louder as the speed increases though, and not the opposite?

aveoturbo

my car makes a noise simialar to what u describe. its at its worst when i start turning right...

XM15

If there is a thumping sound when you are turning, it could be your CV joints.

Killjoy32

its really hard to help someone with a sound problem on a FORUM. Can you take a video by any chance? how loud is it when your In the car?

oh and do you feel a "thump" or just hear it?

BLKLS

cv joints, could be tires too, i ahve heard some starng noises from tires... just look at them, you can see if they are cupping, or better yet run your hand over the outside of the tread. you can feel if they are cupped.

Peterson101

Hub bearing

Mustang65

Regarding the strange sound:

I had thought it was the tires. I didn't give much more thought to it as it is my Girls car. Well, this weekend (4 days after it spent a few hours with a dealer tech. they were driving it around trying to get the cruise control to work consistently. still no joy on that one.) As I was driving down the road I notice that the "whumping" vibration is worse than ever and the steering alignment is off horribly. The wheel was about 10 degrees to the right while driving in a straight line.

So, I took it in for an alignment and asked them to look over the tires and such and described the sound and gave them a list of possible culprits. 2 hrs later they call me up and tell me the alignment is fixed, and they also found the problem.

The Right Front Hub Bearing was fried.

So, I brought it home and took it apart. It litterally took me about 15min. once I had the car jacked up and on stands. Very easy.

I pick up the new hub in the morning and hopefully will no longer have a loud, noisy, vibrating car.

P.S. In case there is anyone here in the Hampton Roads area. I'd like to send out a big F U to Colonial Chevrolet on Virginia Beach Blvd. The parrts manager wouldn't give me a part # for the hub and the clowns in the service department drove the car 4 days before me and failed to notice the massive noise and vibration while driving or at least mention it to my girl friend. Way to go clowns.

I would like to ask though, if anyone happens to have the torque specs for the hub bolts. I would like to torque them properly when I re-install it tomorrow.

Peterson101

It should be covered under warranty.

Mustang65

Warranty expired at 36k.

Replacing the bad Wheel Hub Bearing fixed the issue. The car drives nice and quiet again and without any of the afore mentioned problems.

I do recommend having an alignment done after replacing a wheel hub bearing assy as a bad one may have thrown your alignment out of whack.

I took some pictures on the install and I will be posting a pictorial guide on doing the hub bearing assy under the tittle: Cobalt SS 2.4l Hub Bearing Assy Install