Clattering Sound when accelerate

I'm having problem with my car....when I press down on the gas, it makes clattering sound...the more I press down on the gas...the sound is louder..
I have it check out twice....cost soo much money...and it didn't last long....i'm thinking twice about bringing it to another machenic.. Any one have any idea?? Thanx in advance

If it sounds like pinging, like a tiny metal on metal hammering, it could be detonation. Supposedly this car shouldn't produce high enough compression to detonate, so perhaps the timing is advanced too far and needs to be retarded. Check the timing first. Just putting higher octane fuel in would just mask the real problem.