I just bought a 2005 Chrysler Sebring sedan 2 weeks ago, has 94,000miles on it. Had no problems with anything until 6 days after purchasing the car. I just got on the highway & was about a mile onto the highway & I was already up to speed 65mph & my whole car just starts jerking (bucking like a horse) & I let off the gas & it'd stop. I'd give it gas again & it would start to jerk(buck) again; I had to get to work so I drove it for the couple miles I had left to get to work. As I got onto the off ramp I noticed my car didn't jerk/buck like it was at the higher speed. After work I drove back home & on the highway without any problems. I also didn't have any warning lights come on while it was jerking/bucking. (Before this incident, I had drove to my moms, which is 1hr & 45min away, & back with no problems). I took it to a local mechanic & they found nothing wrong, & they test drove it & checked all the fluids/filters/spark plugs. I did need new front break pads & rotors so I had them change those. Four days later my car did it again.. the jerking/bucking. But this time it was at a low speed & I noticed a ding(like the kind of ding your car makes if you don't have your seat belt on), but again I saw no warning lights come on. I kept driving & was almost to get onto the highway & was about 20mph & my car started to jerk/buck again. I thought it might be nothing so I kept driving to get onto the highway. I turned onto the highway onramp & started going 20-25mph & my car started to jerk/buck like a horse & not let me accelerate any faster. So I pulled onto the onramp shoulder & turned my car off then back on again & let it sit for about 5 minutes & got on the highway & it was like my car had magically been fixed. I got up to speed (65mph) just fine with no jerking/bucking. Again this time none of my warning lights came on & I didn't have any smoke coming out the back end. I of course immediately went strait home, but had not signs of the jerking/bucking. My car also when I start it, all of my dash warning lights come on like they normally would whenever you start up your car, so I know they all work.
Can anyone tell me what is wrong with my car???