Working out the bugs.

[stuart metler]

Just purchased an 02 xc70 yesterday and I love it! However, there are a few bugs to be worked out (as expected). The one I am having trouble diagnosing occurs only when the car is warm and after about 10 minutes of driving. When coasting or maintaining a neutral speed, I hear a faint sound which my g-friend describes as "bells". I would say it's more of a metallic rattle. If I shift out of gear at speed, the sound continues with the same frequency. If I shift out of gear at speed and accelarate and decelarate (rev the engine), the sound continues with the same frequency. I would thus hypothesis that it seems to be independent of the engine and transmission.

Any thoughts?

[Sasquatch]

Have any empties in the back? (-:

[Art]

Welcome to the site stuart.

Is it possible to isolate the general location of the metallic rattle? My first thought would be to check the protection plates behind the brake rotors. Sometimes they get bent and rub against the back of the disc. Hopefully it’s not the first indication of an expired wheel hub bearing. :(

[stuart metler]

It is difficult to isolate any further than "the front area of the car." I am guessing it is probably in the wheel area. Are there other symptoms of a faulty wheel bearing that i should look out for? Any idea of the cost of this repair?

One other thing I noticed, which may be common to all xc's, is that after placing the car in drive and acceleratin to about 10-15 miles per hour, i hear something shift up by my feet. It sounds somewhat like a running over a loose sewer access plate. Kinda of a muffled klank. This does not repeat itself unless you stop and turn the car off and then start over. It happens at the exact same speed every time and it does not correlate to any shift.

thanks for your replies.

[Art]

Stuart,

Cost to have the dealer replace a wheel bearing can run upwards of $500 or more. If you are an accomplished DIYer, there are instructions over at the resources how-to-section (http://volvoxc.com/resources/how-to/index.php) of the site.

Now that I think of it, the ceased wheel bearing on our '01 had more of a loud humm rather than a metallic ring to it although other members here may have a different opinion.

I believe the noise that you refer to is the ABS system performing a self-diagnostic test. This occurs only at startup once the car reaches a speed of 12 mph and is considered to be a normal function of the car.

[tgwillard]

Yes, the clunk you hear is the ABS system doing a check. I hear that on both my XC70 and my wife's S80

[stuart metler]

Just got the car back from servicing. They confirmed that it was actually the ABS system. Thanks for the accurate diagnosis.

[stuart metler]

forgot to mention, the issue I origonally posted about was not acting up while at the dealer (ofcourse). In addition, I think I would change the noise description from "metallic rattle" to something like a small chain dragging on the ground.

If this new description sounds familiar, I would appreciate any insight.

Thanks.

[Sasquatch]

.noise description from "metallic rattle" to something like a small chain dragging on the ground...

How about maybe like a rusty wheel turning and grinding? Sounds like spent bearings coming your way. I'm afraid I might have the same thing. How long can one live with this, and is there a possible catastrophic outcome or is it just a wear-down maintenance issue?