doesnt sound like rocks in a can does it? Thats detonation. Usually happens under load when " lugging" the engine. Like up a hill at low rpm. Its hard to hear detonation in these cars cause theyre just loud rattly beasts by nature, but i know when my expedition had a small leak on pcv hose i could hear that rattle under load. Thats a very large v8 but the sound is similiar, whether you can hear it as clearly is a different story. Might be a loose heat shield, pulley etc..
My new 3" exhaust makes a weird vibration at certain rpms. Scared my at first til i realized where it was coming from.

Throw out bearing, maybe?

Idk what it is...it does scare me...it kind of sounds like rocks in a can...how can I fix this? Is it my pcv valve? I thought one of my pulleys might have been loose...I took a video it didn't look like ot was running straight...what do I do just tighten bolt? Could be heat shield...it is missing the front bolt...just have top two in...I have a 3" exhaust as well...I hope its not TOB

Friend of mine had a 300z and it made a sound like the one you're talking about. He never figured out what it was though. I always thought it was his thrust bearing. Can you post a vid?

Is this the same noise that you already asked about in this thread?

http://www.dsmtuners.com/forums/newbie-forum/434907-rattling-noise-help.html

May be you are driving with a high gear.
If you go uphills on 5 gear and rpm are not high, then you will hear a rattle noise, Just lower the gear and sound will go away (4th or 3th if hill is to bad).

romeen said:

Is this the same noise that you already asked about in this thread?

http://www.dsmtuners.com/forums/newbie-forum/434907-rattling-noise-help.html

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No this noise is different...that noise seems to be my clutch...

My buddy suggested the octane is too low? Could this cause the pinging rattling noises?

ABSOLUTELY , no less than 93 octane. The higher the load the higher the octane you need to stave off detonation. I guess you could get away with 91 but i would never go lower unless you wanted to pull some serious timing. And it doesnt sound like you have link so thats not an option.
Ive been stranded once and ran out of gas on my old zx6r. I used what a neighbor had which was 87 octane. If i got on it, it would rattle. I knew this even at a young age and put 93 back in when i got to town and even a bottle of that octane booster shit to help out a little.
If you ever HAVE to use low octane remember to never lag the motor or put it under heavy load.

Alright awesome news then I hope that fixes it! I'll put 93 and octane and go from there

Do you know this was already suggested a week ago in the other thread? Just saying...

Nonetheless, let us know if that resolves the issue.

You're lugging the motor by driving too slow for the gear that you're in. The rattling noise is knock...a lot of it. THIS IS VERY BAD! It's damaging your motor. Drive in a gear that keeps the rpm's up above 2500. Use only Premium gas for the higher octane (probably 92 in Ohio).

Click to expand...

As long as you run premium your octane should be fine even 91. were you running anything other than that?

I honestly don't remember...I might have had 89 in it becuz they were out of 93

romeen said:

Do you know this was already suggested a week ago in the other thread? Just saying...

Nonetheless, let us know if that resolves the issue.

Click to expand...

Wow your right I'm an idiot and just speed read it...

If that is not the cause get under there and start shaking everything from exhaust to heat shields to drive shaft i had the same problem turns out to be a cover piece that was broken off from bottoming out.