weird knock/rattleing noise

[jepenzes]

1986 buick grand national, when accelerating with the pedal to the floor and when the turbo boost is at its peak the car begins to make a weird knock/rattleing noise does anyone know what could be causing this?

 

[Chuck Leeper]

Need ALOT more ..

1986 buick grand national, when accelerating with the pedal to the floor and when the turbo boost is at its peak the car begins to make a weird knock/rattleing noise does anyone know what could be causing this?

info than that, to help.
Scan tool readings.
Boost reading.
Modifications.

 

[BlackMetal]

Insane detonation?

 

[ChavoLC2]

Marbles

Insane detonation?

That rattle sound like marbles in a can??