I want to tell them to take the car back, and I want to stop paying on the auto loan which is with Chase Bank. Let them reprocess the car. What repercussions can I expect.

Who did you buy the car from, and what specifically does your purchase contract state about warranty? If you bought from a private party, you're out of luck as you bought the car "as is" (unless you have a written contract with the seller that states otherwise). If you bought it from a retail used car company, then you may have some rights under your state law - in Illinois for example by law the power train is automatically warranted for 30 days from date of purchase, unless the car was specifically sold "as is" on the contract. But since you've already driven the car over 2500 miles I doubt that any such warranty would still apply. Still - let us know when you purchased the car and in what state.

If you just stop paying the loan, the car will be repossessed, the lender will continue to demand payment for the difference between the market value of the car and the outstanding loan amount, and your credit rating will get killed. You certainly would not be able to take oiut another loan on whatever car you're thinking about replacing this one with.