heres the problem. been reading the site and havn't found any anwers yet. i have a 93 lumina with a 3.1l motor. i noticed a knock but didn't think it was that serious till it got louder and louder as days past . well a week later the car stopped and wouldn't go no more. the last sound it made sounded like one of the pistons were loss or something. i can start it but it won't have enough energy to go and it sounds real real bad. i mean its a loud knock. i feel that its soo loud that it might damage the head more. does anyone have any experience on this matter. i am going to take it a part down tll the heads are exposed to see what the damage is. i have been told that the computer might be to blame but i am just having guess thrown at me. i down think its a pistonslap cause the car is not moblie any more. i can't drive it any longer. help please! thanks

Sounds like you probably broke a piston. Take the oil cap off and see if it's huffing out air hard from the crankcase when you crank it over....if it is, don't bother taking it apart, it's toast.

Sounds like you probably broke a piston. Take the oil cap off and see if it's huffing out air hard from the crankcase when you crank it over....if it is, don't bother taking it apart, it's toast.
i wish i never opened that can of worms caus i already took it apart. someone was telling that the torque converter could be loose and will make that noise but i never once had a transmission problem so i really think it has to do witht hte pistons. i 've taken everything off but the tw heads and block. thats still attached. i have a 91 lumina. i am thinking that i can use the parts from there?

Loose torque convertor knock sounds like all hell is breaking loose just like a rod knock, yes, but it won't make it run bad. It'll run just like normal.

PM to Richtazz, he knows more about compatability from year to year in these motors than me...