First off, I'm new to the site, and have spent the last two days reading everything that caught my eye. I think when my Bonny dies I'll get another one just 'cause now I know where to look when something goes wrong

Anyway, for the last few months I've been hearing a bit of a faint rattle from an undetermined location -- it sounds sort of like the sound you might hear by putting a penny in a soda can and having someone shake it rather quickly across the room. (It'* a little lower in pitch, though.) I can't get it to happen with any regularity, and the times I *do* hear it, it always sounds the same, and I'm usually going about 30 mph at maybe 2k - 2.5k rpms. Letting off the pedal or depressing it further usually causes the noise to disappear. Also can't get it to happen when I'm idling in the driveway.

Any ideas?

Forgot to include that as far as I know, all my engine parts are factory originals.

-b

sounds like the cat to me. does it sound like it below you?

I'll run out and hit it a few times here in a few minutes.

It'* hard to pinpoint exactly where it'* coming from, since it'* pretty faint and doesn't seem to transfer into the interior very well. I can hear it best when I'm coming down my street with my windows open, which has big wooden privacy fences on either side and bounces the sounds my car makes back at me. If the cat'* not rattling, any suggestions on how I can try and localize the sound more accurately?

-- ed.

Okay, there'* not a whole lot of room to get under there and kick stuff once you're past the rear axle, is there? :( Upon shaking the muffler, I heard something that sounded like a screw rattling around, but it didn't sound quite like the sound I describe above (at least, not from below -- who knows what that would sound like with exhaust pouring through the muffler and me inside the cab?). Heat shield seemed to be attached okay, though when I pulled on it the first time it popped like a warping cookie sheet like it had been wedged up against something. Couldn't get to the cat to give it a good shakedown.

-b

My cat made exactly the same noise you described, under the same conditions. Took me a week to nail it down.

Mine does that too. I always wondered what is was. I always thought it was some kind of intake or exhaust resonance but never worried too much about it cause it does'nt sound serious.

I've shaken just about everything there is to shake underneath the car, and nothing'* rattling, squeaking, or otherwise. I've revised my initial guess as to when I can hear it -- it'* usually at light load, maybe 1.5k rpms, at almost exactly 40mph every time. (It might happen at all engine speeds, but at 2.5k maybe I pass through 40mph fast enough that I don't hear the rattle?) I've gathered from some other posts I've read that the torque converter clutch locks up at 40mph, right? Maybe it'* related.

But you're right, Steve, it doesn't really sound serious. I'd just like to know what it is, so when it DOES sound serious, I don't have far to look

-b