I stayed away from any gm car with the 3.1 because of piston slap. the day after i took lumina home i noticed loud knocking noise from engine. returned next day to quirk auto park, service department, was told i had carbon on pistons that day they did a top engine clean. i was told to drive for 1 week , at end of week returned to service dept, noise was louder, was told pistons needed to be replaced. was told by don baker you will never hear noise again. well 2 weeks later got car back. noise gone so happy. 1 month later noise back, even louder than before. took back to dealer. same person who told me never would hear noise again, now says that the noise is "NORMAL"?

well i traded car in lost lots of money. got pontiac bonneville 3.8, than got 99 buick lesabre 3.8 seriesII both of them no piston slap. thought i was safe with the lacrosse 3.8 series III but i am now going through the same thing, as with the lumina. waiting for gm to tell me that this is "NORMAL". it is to bad, buick lacrosse very nice car, but with 18,000 miles when noticed knocking, whats to come? like with lumina noise didnt go away when warmed up. i just hope gm comes up with a fix. like car dont want to trade. but every time i hear a 3.1 start in parking lot from 10 cars away you can hear it. just makes me sad. if you are having same problem please call gm and ask them to fix problem.