For the past week or so I've noticed a tinkling sound, almost like a thumb piano, or a pinball machine, coming from the exterior of the car. It seems to only happen when I'm accelerating, usually just in the first three gears, but it doesn't happen when decelerating, or when I get to the fourth gear. FYI 2000 Civic LX automatic. Anyone have any clue what it could be?

Might be the a/c tensioner pulley.. rev engine up while parked and listen for metallic noise. Also, can remove a/c belt and spin by hand..if noisy or doesn't spin easily (bearings) then replace it. Other than that possibly brake dust shield. From your description it is hard to pin point and is from exterior or engine bay? can be very hard to tell sometimes.

No AC belt, the compressor needs to be changed. It only seems to happen when I'm actually driving, so it's hard to pinpoint where the sound in emanating from.

Maybe try riding around with someone in the backseat or backseat folded down to isolate noise front or back.

Locate an area to look in.
Put a passenger to good use.
Maybe stick your head (or your passengers head) out the window(s) and turn it everywhich sideways so you can discern if the noise comes from front or rear, bottom or top, left or right, etc.

(I found a sunroof rattle this way, five other people could not tell the noise came from the roof LOL)


Get underneath and thump the exhaust system with your palms? Maybe heat shields have rotted loose or a hanger bracket rusted off.

From OP's description this seems to be the most likely source.

It seems to be coming from the front driver side wheel well