2002 V70XC diagnosing driveline noise

[leapdragon]

Hi all,

Continuing to work methodically through the "need to dos" on the 2002 V70XC that I recently acquired.

I'm now as far as tackling a driveline noise that has been there since acquisition. Can anyone help me to diagnose before I spend actual money to arrive at a diagnosis?

*Update: I went out for a drive this morning on a *very* smooth winding road (took me a while to get there) to try to get a handle on this. I was wrong about some things before.*

• Very subtle vibration/noise, reminiscent of tire noise—not clanging or clicking, barely audible
  BUT you can feel it in the gas pedal and shifter
  And is not constant intensity, but rather pulses ("vroom...vroom...vroom...vroom...vroom" maybe 2x/second)
  Happens only when car/wheels are actually moving (does not happen when revving in P)
  Happens only between about 35 and 70 mph (again, only when foot is on gas, but even at constant speed)
  Is almost undetectable with foot off the gas, but still there
  Doesn't feel biased to one side or to the far front or far rear
  *BUT* when turning left, disappears almost entirely, when turning right, speeds up and gets louder

No torn boots under car, and no obvious leaks.

Front wheel bearing? Axle? I'm guessing driver's side, since it increases in speed/intensity when turning right (extra load on driver's side).

[jonesg]

Sounds like you're on the right track with that analysis.
To me its wheel bearing drone.
Supposedly if you jack it up, spin the wheel and put your hand on the coil spring it should be detectable.

[Georgeandkira]

My car just started doing this yesterday. Noise comes from driver's side.

Inaudible as I'm accelerating. Audible as I coast. Disappears when I turn right. Returns immediately when I turn left to center. It quiets down only a bit when I go into a loaded left turn. I wonder if I should order 2 bearings or just do the suspect one.

[leapdragon]

Yup that sounds right. Mine is slightly quieter when coasting but still there.

I have bearings for left and right on the way. I'll replace them both (car is at 140k so can't hurt) and then if it's still there I'll look to other stuff next. Also have fluid for angle gear and rear diff on the way and will do that at the same time since I doubt it's ever been done.

Once I get this noise gone, next is to tackle a weird rattle under heavy acceleration at >2.5k RPM, I'm thinking something in the upper exhaust. But one thing at a time.

[leapdragon]

Just in case anyone finds this through search and wants to know down the road—

Replaced left and right front bearings today. The subtle "woo woo woo" noise that sounded almost like tire noise is fully gone. It was indeed the wheel bearings. Funny thing, the with the old bearings off, they don't actually feel bad when you rotate them. If someone asked me whether or not each one was good just by handling them, I'd have said they were fine.

So—noise resolved. It is not a job I would like to do again. It took me longer, and required more exertion, than most any other "car thing" I've done so far. And I have created two problems for myself:

1) Alignment is now slightly out. Camber is off on the driver's side and toe is off on the passenger side. *sigh* This despite the fact that none of the "adjustables" were touched. But I suppose when you have all of the front-end parts flapping in the breeze while you bang around to free things up, and you have to reposition them in all kinds of odd ways, stuff like this is bound to happen.

2) I don't think the rotors are running true. I have some "shimmy" feel when braking. This tells me that I didn't do a good enough job of cleaning them of rust and debris on the back. And since I don't know which side is causing it, off the wheels come again tomorrow morning. And the calipers. And the rotors. So, future reader, if you do this job—be double-careful about cleaning your rotors up, or you'll be sighing as I am about basically having to do a brake job the next day.

[abscate]

My car just started doing this yesterday. Noise comes from driver's side.

Inaudible as I'm accelerating. Audible as I coast. Disappears when I turn right. Returns immediately when I turn left to center. It quiets down only a bit when I go into a loaded left turn. I wonder if I should order 2 bearings or just do the suspect one.

There is no saving in labour doing both, so just do the one that is noisy. The bearings are about $100 a piece, so not cheap.

You can easily drive 10,000 miles on a pretty loud bearing with impunity, so no rush. I did this twice on my 1999, and have 10,000 on a slightly noisy 2005 which I will take to PHL next week.

I experienced the same 'unable to tell loud from new by feel'

Come up to ALB if you want to Volvo Fest sometime! Take the new Pete Seeger Bridge and roll up the Taconic in Fall..

[Georgeandkira]

I'm in. Just let me know when.