Q: I have a 1996 Ford Contour with about 66,000 miles. The problem is that it developed a humming and roaring noise along with a vibration in the front end about 10,000 miles ago. I was told it needs a new hub bearing.

The car was well taken care of and driven by a grandma. Is it possible for this bearing to go bad so soon? What do you think? – J.E., Lockport

A: Yes, it’s possible for the bearing to fail so soon. I would recommend that you take care of this problem immediately as complete bearing failure could result in a loss of control. I’d also suggest that the other front wheel bearing be carefully inspected and replaced if necessary.

Only averaging about 5,000 miles per year, I figure that your Contour has spent a great deal of its life parked and/or making short trips. That may have played a role in the short life of the bearing or the bearing could have been defective.

Generally, wheel bearings fail from wear and/or a lack of lubrication. The front wheel bearings on your Contour are sealed, though. That means they can’t be periodically serviced and re-packed with grease. You’ll want to make sure the replacement bearing is of high quality so it will last a long time.

Q: I have a 2005 Volvo XC90 with 188,000 miles. When I back up and apply the brakes, there is a clunking sound. I’ve had people look at it and they say it’s not the brakes. The brakes are OK. Also, the dealer hasn’t been able to find anything wrong. I’m curious as to what your thoughts are. – W.R., Algonquin

A: The clunking noise is likely the result of a loose bolt or worn part. I wouldn’t feel comfortable driving it around until I found the source of the noise. Find a repair facility that has a wireless chassis ear. The wireless chassis ear costs a little more than $200 and it’s one of the more effective tools in helping a technician pinpoint where noises are originating from.

There could be a loose bolt on one of the brake calipers, caliper mounting brackets or the brake pads might be shifting around in the caliper. There could be a loose bolt or worn part in the suspension system. Visit www.asashop.org and contact the shops in your area by phone to find a shop that has a wireless chassis ear.

Q: My sons have given me one of those GPS units as a gift. If I keep the unit plugged in and charging (24/7) in my 2006 Chevy Impala, am I going to drain the battery in my car?

Everyone is telling me to charge it, but not in the car. What do you think? – J.G., Plainfield

A: I would agree with not leaving it plugged into your car’s power outlet when the car is not in use. Yes, it could drain the battery. You can certainly leave it plugged into your car’s power outlet whenever the car is in use. But you’ll want to unplug it when you turn the engine off.

I’d also recommend that you don’t leave the unit, or its mounting bracket, sitting in the car in plain view. That could be an invitation to thieves, who may break a window and quickly snatch that GPS away.

Questions for Ira Siegel? Call the Auto Advisor Hotline at (708) 633-6839 or e-mail autoadvisr@aol. com. Siegel is an automotive instructor and an automotive service excellencecertified master auto technician.