Underhood rattle noise -- PCV?

[Jon]

I've posted this before. I am wondering if anyone else has this noise. My engine makes a noise that sounds just like a baby rattle when under light throttle or coasting. The sound is a constant frequency at all rpms. All is quiet at idle and when under load.

Do you think it could be the PCV acting up?

 

[JMHCobra]

My '03 has the exact same rattle problem under steady throttle at speeds of 40mph and above. However, when accelerating or coasting, the problem doesn't occur.

It almost sounds like pre-ignition, but this shouldn't occur at steady street or highway speeds.

Power does not seem to be affected, but the noise is annoying.

Any ideas or suggestions? Currently I don't have any idea what the problem could be.

 

[Jon]

I have no idea either. Maybe one of the catalytic converters?

 

[SnakeBit]

I have been trying to track down my rattle. It almost sounds like a vacuum leak at the firewall. But so far, I cannot find one.

The other possibility is the plastic cover between the lower front edge of the windshield and the back edge of the hood. This rattle has been known for years due to loose clips. I still have not gone into mine, but will one of these weekends.

 

[bassin247]

Hey guys. I had a rattle and it ended up being improper installation of the brake pads. Try pressing the brakes to see if it goes away.

 

[a94cobra]

I have a rattle or rather more of a ticking noise or a tapping noise that is a constant speed. It doesn't speed up with the engine. It is noticeable above 20mph or so. I only hear it with the top down and sounds like it comes from the top of the windshield. I don't remember if it's there when accellerating or not. Does that sound like you noise at all - Jon?

 

[Jon]

Mine makes a similar sound but is clearly coming from the engine compartment.

Like yours, mine is noticeable from about 20mph and does not change in frequency.

I am starting to think it is one of the cats.

 

[Hunter6]

I had a rattle...turned out my hood blanket was loose...just an idea.

 

[mike79]

I have a very similar rattle. You can hear it at idle though, barely. Sounds like a baby rattle. As I speed up, so does the sound. Like the rattle is being shook more. After 3000RPM's, I dont hear it anymore. Took it to the dealer, they said "Duhh, uhm, you know this car has a supercharger on it, right?" I looked at the guy and just gave him a dumb answer in responce to his dumb question. Asked a few guys at the dealer, they said its normal. I dont think it is though.