Q: Thudding and thumping during acceleration from a stop and steering vibration at highway speed on a 2000 Nissan Pathfinder

If it’s happening when you stop or accelerate, it is often a broken motor mount or transmission mount. I’ve got a video "how to change bad motor mounts on your car" that shows you how to check it. You put a little piece of wood under the engine, jack it up, and when it goes up see the motor mounts.

When transmission mounts break apart, if you see air between them, you know that they caused that. It’s almost always the motor or transmission mounts, when they thud like that. You’d want to pray it’s that and not the transmission going out, because Nissan Pathfinders are notorious for having automatic transmission problems and they cost a fortune to repair.

If you would like to have a technician look at it instead, I would have a certified mechanic run the necessary checks to diagnose your car’s noise and make the correct repairs done for you.