Ok, I have heard this rattling for a LONG time in my engine. I mean it is the WEIRDEST sound almost sounds like a connecting rod is vibrating or something. I know that some engines just have certain "design" sounds, some rattle etc. But this sound really kinda worries me. I was under the hood this morning and was doing quick revs and it seems to do it the loudest when its winding back down from high rpms. I placed my hand on the alternator while it was idling and you can even FEEL the rattling, it may be just one of those design things but I am kinda worried about this!

Anyone else who has an LN3, give me your thoughts on this!!!

I've got it too.... no idea what it is. kinda concerns me too, because i think it'* kicking the knock sensor on and pulling timing. May not be a bad idea for you to scantool your car wj... see if you have the same thing.

And it'* done this since i've got the engine installed 250mi ago. So who knows how long before that.

You know I'm actually wondering if it really only is a noise of design.

Umm...well I don't own a scantool, but the last time I had one on there I was showing barely any knock...maybe a couple points at 3/4 to WOT, but that was about it. and this noise obviously existed at that time. But yeah, it kinda does sound like pre detonation.... :?

I'm confused.

Mine sounds like metal on metal... like if a main bearing didn't have oil on it, that is what it would sound like, and it'* the most obvious coming down from 2k w/o load. It'* only there on the decel.

Do you know what the total advanced was?

Yeah, thats exactly when mine does it, coming down from about 2k no load. Metal on metal...like clacking almost.

And no, I think I need to re-borrow that scantool again. I hope i can. :?

Well you tell us Don, you own two of em!

hmm, would you like me to go get a vid of it?

Don, just tell me what it is and if i should be worried about it!