Clicking or tapping noise from engine

My car has been making this noise for a long time and i dont think i remember it ever not doing it. When the engine is running, no matter hot or cold(usually is louder when hot) it makes this clicking rattling noise. It's hard to explain. The sound is unique and i cant really compare it to anything else. It sounds like maybe a spray paint can rattling and or heavy clothes with buttons in the dryer flopping around making a metal tapping noise.
It's not a clicking noise but it is more like a constant loud rattle at idle and it usually quiets down if you give it throttle. I dont know if its just because the engine is getting louder or not.
THe noise is not quite loud enough to be considered a bad problem but is rather noticable when walking up to the car or openning the hood. I've just wondered what it was.
I might be able to get a vid up of the sound later.
THX

remove belt run motor...see if problem continues..if it does I would be looking at rockers

Catylytic convertor could be broken internally, when cold try hitting it with a piece of wood, see if it rattles.

Here is the main video. With the camera under the hood you can hear the noise really well.
http://media.putfile.com/Idle88


Here is a video of the camera under the car with a short rev.
http://media.putfile.com/reg89


I made a vid of me shutting of my engine. When i shut off my engine, it makes a wheeze kinda noise, its hard to hear unless you have the sound up. Ive noticed it for a while but thought nothing of it.
http://media.putfile.com/Growl16


I tried hitting the catylytic converter and it sounded solid but a few moths ago it rattled. It kinda went away by itself.

THX

If the cat rattled before and not now it could have broken up into smaller pieces and wound up in the muffler. Doesn't just " go away".

I know the cat is still a problem but im not sure its "the" problem. When it used to rattle you could hear it on the outside under the car. This noise it radiating from the engine bay. The videos show it pretty good.

Is the alternator vibrating?

my car does the same thing, but only around 1900-2300 RPM. i held the gas while listening underneath the car, and found the noise to be coming from the exhaust, after the cat converter but before the muffler. there is a heat shield in the area where it makes the noise. this seems to be where its coming from on my car, because the shield appears to be loose. ive been too lazy to fix it. i hope this helps, but after looking at your videos im not sure that we have the same problem. i suppose its worth checking though

good luck!

-Rob

my car does the same.... i think it is the rockers, or lifter though... try starting the engine... and this'll sound strange but trust me... open the oil cap next on top of the rockers... if it get's louder, you found it...

in fact i'm positive my car makes the same kind of sound..,..... i remember reading somewhere that one of the bearings on the camshaft was mass produced with a gap that was a little too large or something. i think it is the valve train. i wouldn't panic though, because it sounds fairly minor... just don't quote me on it.

Hey Ofnarcr. I was wondering if you ever found out what was causing that racket in your engine? I have a 88 LeSabra with a 3.8 that sounds just like it. Thanks

i have the same problem too... so i decided to take the injectors out and clean them up... seems to have helped a little.... maybe try that

Yeah, i still dont know what the tapping is. I think it is alright though because i have had no engine problems since i have had the car.