Hey everyone....

My car has this weird rattling noise when hard on the gas. It sounds like metal on metal. I checked the exhaust and saw nothing. When the car is in parked and I rev it,,, it doesn't do it... any ideas?

Thanks

 

It might be one of these: detonation, pre-ignition or "ping".
What state of tune is the engine in? What grade of fuel are you using?

 

I use 92 or 93 octane....not sure what you mean about the state the tune is in...