With less than 1300 miles on the vehicle, it began to buck and surge in traffic at 65mph, and the tachometer began swinging wildly from 0 to 2500rpm. After getting off to the side of the road quickly, where it stalled again and again, I called Hyundai roadside assistance for a tow to the dealer. They examined and drove the car, and told me it wasn't acting up for them, and suggested I take it home while they ordered an exhaust purge valve per a 2.4L engine problem service bulletin from Hyundai. While on the highway toward home, it began bucking and the tachometer was swinging wildly again, so I got off to the side, where it repeatedly stalled, and again I called Hyundai roadside assistance for a tow back to the dealer. They rented a car for me, and over the next week replaced the purge valve, but the car also died on them, so they did a more thorough analysis, which showed a failed crankshaft position sensor, which caused ignition spark failure. After replacing that, they called me to come get the car and take it home. This time it failed just as I reached my driveway, again bucking and stalling with the tachometer swinging wildly up and down. For a third time, I called roadside assistance for a tow to the dealer, which promised a search to determine the cause of the failures, involvement of the district manager, and an attempt to obtain a different sensor model in case the batch of available sensors was "bad". subsequent phone calls to the dealership have not produced any answer as to the cause of the failures, delays in obtaining a suitable replacement part, and so far, a total of 18 inoperable days for my new car. This failure is a serious issue; a person at the dealership told me that "other (Hyundai) vehicles with the same engine had the same problem" one of which was there while I was at the dealer waiting for my second rental car. I repeat; this is a serious safety issue; such sudden loss of engine power in traffic can have fatal results!

- Syracuse, NY, USA