Hi guys. Let me turn your attention in a different direction. Any mechanic with only a few months experience has heard a noisy wheel bearing. Based on your dandy description, that's the first thing he should have headed for, not things that don't make noise on the highway like struts and brake pads. Standing next to the car and listening isn't going to work because there's no vehicle weight on the bearings. They will rarely have play in them either when they first become noisy. I don't say this often or lightly, but I have to wonder about your mechanic's competence, training, or experience.
You noticed the noise doesn't change when you steer to one side. That's also a useful observation. On most cars with the less expensive pressed-in bearings, if the left one is noisy, it will get quieter when you turn left and more weight shifts to the right side. That can be observed by simply changing lanes on the highway. With the more expensive but less labor-intensive bolt-on style bearings, it is real common for the noise to not change when turning. Additionally, on many cars such as the Dodge Intrepid, it can sound to everyone in the car like the noise is coming from the right wheel, and it turns out to be the left bearing that's noisy. On those cars, the only accurate way I found to identify the noisy bearing was to run the car in gear on a hoist and listen next to each one with a stethoscope. One will have a rumbling sound, but then the other one will be REAL rough sounding. That's the bad one, but you won't hear it without the stethoscope.
Another expert here says he finds them by placing his hand on the coil spring, then rotating the tires by hand. He can feel the rumbling from the bad bearing. I haven't had a chance to try that yet.
There is also a tool called a "Chassis Ear" that is useful in finding the source of a noise. It is a set of six microphones, a switch box, and head phones. You clip the microphones to suspect parts, then switch between them and listen during a test drive. By moving the microphones around, you can zero in on the source. Your mechanic gets a pass if he has never seen this tool. Many have never even heard of it.
Brother KHLow2008 is right about the wheel bearing. Just based on the description of the symptoms that's the first thing to look at.
Sunday, August 14th, 2011 AT 8:27 PM