I just switched out my alternator because it failed and while driving the car to see if anything went wrong a noise that the car hadn't made in a while came back. I've had the car looked at before for this noise but I've never really had a straight answer as to what it is. The car only makes the noise when it is idling either in reverse or in drive. If I switch to park or neutral the car wont make the noise. If I let go of the brakes even a little bit and the car advances the car stops making the noise. It sounds like metal rattling back and forth sort of like a playing card in a bike tire. It doesn't affect the handling or performance at all(at least to what I can tell), but at this point it gets a bit embarrassing to have the car make such a loud noise at every stop light and stop sign. Can it be the brakes? Maybe something with the transmission?
There is a tool you might be able to borrow or rent from an auto parts store that borrows them called the "Chassis Ear". It is a set of six microphones, a switch box, and headphones. You clip the microphones to suspect points, then drive around while listening with the headphones. You can move the microphones around to zero in on the source of the noise. Be aware that many mechanics have never seen or even heard of this tool. Suspension and alignment mechanics use it to find rattles, squeaks, and other noises.
I think I'd start by looking near the transmission inspection cover. One possibility is a loose torque converter bolt. That can happen on any brand of car and is relatively not serious but it can be noisy.
October, 20, 2012 AT 2:56 AM
The car didn't do the noise at all today so I'm going to have to wait till it starts up again. I'd never even heard of that tool either, seems like a really clever way to find a noise. Thanks man.
October, 20, 2012 AT 3:31 AM
They're 200 bucks on the tool trucks but I found some new ones on Amazon. Com a while back for less the $70.00 for the wired version. There's a newer model that has two wired microphones and four are wireless.
September, 7, 2013 AT 3:46 PM
I have this EXACT same problem with my Contour. It IS rather embarrassing when I am at a stoplight or when I park. I have found that when I come to a stop, if I turn the air conditioner off - the noise decreases quite a bit. I don't understand that.
September, 7, 2013 AT 9:18 PM
Given that this would appear to be a common problem, you might consider first removing the serpentine belt, then driving a short distance without it. At least that will tell you with certainty it is belt-related or it is not. Don't turn the steering wheel unnecessarily as the steering gear will push fluid out the reservoir and make a mess when the power steering pump isn't running. It can be hard to burp the air out later on Fords once the power steering fluid is refilled.