Rattling noise

[RoushMan3]

I've recently started hearing a rattling noise, here are the symptoms:

When I start the vehicle, it rattles as the RPM's increase then decrease upon start. Funny thing is that if I turn the car off and then back on, the rattling does not happen again. So it seems only to happen when the car has had a chance to sit for a while.

It also makes this rattling noise when I'm lightly on the throttle, it does not make it when I am completely off or completely on. It also does not make the noise when at idle so I've had a hard time trying to figure out where its coming from.

I have no cats.

It's a 2001 SOHC w/ about 85k


Any ideas?
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[RickieFrat]

Where is it coming from? under the hood - center of the car - the rear

I know every once in a while my AC clutch rattles and sounds the way you mentioned.

 

[trinity_gt]

Yeah, without knowing where the sound is coming from it's hard to guess.

If it's from the front of the engine you may be looking at timing chain guide/tensioner issues...

 

[Maxpowers]

I'm assuming you mean metal on metal rattle and not something plastic inside the car.

Have someone looking under the hood while you start the car and see if they can pinpoint the location of it.

 

[RoushMan3]

Its coming from the engine bay. Had someone hold the RPM's while I tried to listen but I can't pinpoint where the noise is coming from, my best guess would be from towards the bottom of the engine.

It seems to make the noise in roughly the 2500-3500 RPM range

 

[wmburns]

Normally, I would vote for bad cats but since you do not have any..

Get yourself a mechanic's stethoscope and probe around.

 

[Kilgore Trout]

Could be a million different things. Non-specific "rattle" noises cannot be diagnosed over teh interwebs. Good luck.