High Rev Marble noise?!?

[John84GN]

My GN does this "thing" at the top end of 1st gear, right before it shifts into 2nd, it gives a knock, kinda like a marble sound, just at this point, and at no other point across the powerband, except at the very top end, also there is no loss of power...Does this sound like bad news?...I was told that a new fuel pump, and fuel pressure regulator would take care of this, as well as using some higher octane gas...any idea's?!? The car is BONE STOCK, w/ 70K on it...Now, this only happens if I don't "let" the car shift, and I'm just flooring it, all the way up through the powerband. Of course, if I know when it needs to shift, I can tell, then it doesn't do it...any thoughts?!?

 

[Buick From Hell]

I'd be very wary of "marbles", it sounds like very heavy knock to me! My car used to do that when it was new, I'd just have to back out of it...the reason MY car did this is because it came from the factory with a non-functioning spark control module, so I was getting NO timing retard from knock! I got ONLY knock, and lots of it! And I had NO idea it wasn't normal because it never set a trouble code! I just figured I had to live with it because of the crappy gas we have around here!

I'd try to score some 118 octane and see if that stops it!

 

[REDS HOT AIR]

mine does that too even on good fuel some ...i would love to know how much timing the stock chip feeds these hot-air cars at high rpms ..
i've tried all kinds of crap to get rid of it and now i've gave up i just add as much octane as i can and turn the radio up ..

but i dont recomend that if you really dont want to hurt the motor get a chip for the car from someome like joe lubrant that wont feed so much timing to it

i was just listening to the marbles a little while ago myself but if mine pops then i'll just push it in the garage and put my new motor in

i as listening to mine at 20# boost on 110 octane..

 

[Buick From Hell]

a little test for you guys and your "marbles"..

watch the drivers-door rear view mirror. If you're getting ANY grayish or black smoke when the marbles start, you're knocking!