had engine replaced,pick up car, drove for 4 minutes, now sounds like rocks roll

I did. I returned it to the deaIership 4 minutes after driving it. I just have a feeling they are going to try to say that it is not the engine. I don't see how it could not be. I had the same thing happen 14 months ago, and they replaced the engine then. I just paid them $2200.00, I can't afford any more. Any help/advise would be appreciated!