1998 S70 T5 Rotational whump noise

GinkoJK2 · Post by **GinkoJK2** » 18 Jan 2015, 23:06

My 98 s70 T5 with 204,000+ miles on it has a rotational whump whump whump sound that I'm trying to diagnose. It seems like every rotation of the wheel/axle it makes the noise. From inside the car it seems like it is coming from the front driver side. I can feel it in the floorboard and apparently the dash can feel it because it is squeaking. It occurs at all speeds, and I can't tell any difference between accelerating, braking, or cruising. The sound/vibration goes away when turning left like you would expect from a bad wheel bearing. The noise is there while going straight and turning right. It's not a constant humming or grinding noise so I don't think it is the bearing, but I could be wrong. I recently replaced pads and rotors on all four wheels which had no effect on the noise. The front tires are new too. I also replaced the struts not too terribly long ago. I've searched and haven't been able to find anything that matches these symptoms. My first thought is cv joint/axle, but I suppose it could be wheel bearing, lower control arm, or strut.

Anyone have any ideas?

Post by **rspi** » 19 Jan 2015, 02:18

Bad wheel bearing.

GinkoJK2 · Post by **GinkoJK2** » 19 Jan 2015, 07:17

This guy has what sounds like pretty much the same as what I have going on. Except his sounds more clicky and less bass-ey than mine. I suppose that could be because the camera mic isn't going to pick up the low tones. I jacked up the driver side and grabbed the wheel at 6 and 12. There is some noticable play. There is also play at 3 and 9, but I think that is mostly because there is slop in the rack. I guess I'll be picking up a hub/bearing for sure then, huh?

GinkoJK2 · Post by **GinkoJK2** » 19 Jan 2015, 07:37

Oh, I forgot to mention the ABS light is on intermittently. Sometimes is stays on after the initial start up test. Sometimes it comes on later. And sometimes it goes off after a while. Could a bad bearing cause that? It started after I did the struts so hopefully it's coincidence and I didn't break a wire or something.

Post by **Ozark Lee** » 19 Jan 2015, 07:47

A bad hub doesn't always present with play but when they get real bad there is a bunch of play. The play you describe could be a bad ball joint, bad tie rod ends, or a bad hub. What you need to do is jack the car back up and, as you are rocking things back and forth actually look at and feel the tie rod ends, the ball joint, and the brake rotor. For the purposes of this test remove the wheel and leave the locater pin in the rotor. With a bad ball joint or tie rod end the rotor and the steering knuckle along with the caliper will all move together. With a bad hub the the brake rotor will move around independently of the steering knuckle and the brake caliper. Any play whatsoever in the hub is too much.

As to the ABS light, when a hub gets real bad the reluctance ring on the end of the axle flops around and changes the distance between the ring and the wheel sensor and that can freak out the ABS. If your ABS module hasn't been rebuilt, however, that is the more likely cause of the ABS issues. ABS modules have a 100% failure rate.

...Lee

GinkoJK2 · Post by **GinkoJK2** » 19 Jan 2015, 12:05

Thanks for the suggestions. I'll try to check it out tonight when I get off work. Based on everything else I've had to do to that car (and my luck), I'm sure it's probably all of the above that needs to be replaced. We'll see.

Post by **misha** » 19 Jan 2015, 12:15

If you have clicking,mostly in turning,that would be bad cv joint.

If there is a humming and light grinding noise as the wheel rotate..that would be wheel bearing.

Post by **E Showell** » 19 Jan 2015, 12:19

Another possibility is that you have thrown a wheel balance weight. Check to make sure they are all accounted for.

Post by **misha** » 19 Jan 2015, 12:21

E Showell wrote:Another possibility is that you have thrown a wheel balance weight. Check to make sure they are all accounted for.

Steering wheel would shake in that case.

Post by **abscate** » 19 Jan 2015, 13:18

That's much more CV sounding than front wheel bearing.

Bad cV joint sounds like a train on a track

Bad bearing sounds like a low growl.