The car was running very good till the previous day. all of a sudden i started hearing some weird sound from the engine area,may be it is some torque converter problem. once i start the car and try reversing it, it works very good and when i try to put under drive mode and move forward,it is not moving. I need to turn off the vehicle,bring the gear to parking, and then try keeping in DRIVE mode and it runs very fine. suppose i stop at a signal and bring down the acceleration to zero, it again stops moving. again i need to turn off the vehicle, bring the gear to Perking mode, start the car and put it in the drive mode to make it run normally.I have checked for any leaks, there is noting such as far as i noticed, and all the oil levels are OK. Can u suggest me the actual problem and give me an estimate. Thank you.