06 pintiac grand prix

Sounds like a loose or corroded battery cable. Check both cables including the positive by the starter. If they look ok, check starter solenoid

@lrodri911. Will a corroded battery cable let it work sometimes? cause sometimes my car starts with no problem and sometimes it dosent?

It can do it intermittently but to make sure and it's cheaper just to check and rule that out. If it still happens, then u need to get a volt meter and see if voltage is actually getting to the starter and the starter solenoid instead of guessing, it'll be more expensive to throw parts at it without checking first

I agree. Sounds like a loose connection or bad ground somewhere. First find the problem, then fix, not the other way around.