I have an 01 a4 2.8 manual with ~140,000 km. Just bought the car from an original owner a month ago, car was solid, passed an inspection and only needed breaks. I was on my way home from work this evening on the highway doing about 120 km/h in 5th. About 10 minutes in I started to notice a weird feeling when i let up off the gas, almost like a knocking feeling through the stick shift, and the car would jerk as if I abruptly downshifted. I kept driving and noticed a few minutes later that my speedo was jumping all over. I got off the highway and downshifted through all the gears and the car was doing the jerking even more after I let off the gas. The speedo was jumping even more, then dropping to 0, even stopped in neutral. All other gauges were fine.I eventually made it home and turned the car off, let it sit for 5 minutes, and drove it again. Everything was fine, no jerking or speedo problem. I let the car sit for an hour and took it out again for 15 minutes, putting it through a solid test. Everything worked fine. I should also mention that when I washed it before going home from work, and that on my way home I had the heated up high. Cold winter

I am assuming an electrical fault. Could anyone chime in?

Thanks,
Nathan

 

Have the throttle position sensor checked.