Nissan Xterra- every few weeks I'll be driving along and without warning, randomly the car will get stuck meaning the speedometer and tachometer freeze up and the car will not move faster then the speed I got "stuck" at ...Like if I'm going 40mph and it decides to freeze up the gauges freeze up and I give the car gas and it does a humming sound and won't move faster then the 40mph... then if I take my foot off the gas the speedometer and tachometer will go down normally, but as soon as I put my foot on the gas again it will speed up, but won't go past that original 40mph it was stuck at...

the only way to unstick it is to pound on the dash and then the car will move normally, but recently it's not even responding to that, it now won't move faster unless I put it in neutral, rev it a little and put it back in drive, it will run fine for another week and then the nonsense of the speedometer and tachometer and speed freezing will happen all over again. What could it be?

We replaced distributor, speed sensor (3 times with OEM parts), changed the fuel filter, mass airflow sensor, put in a new battery ...Nissan said there could be a short in the gauge cluster? does that sound plausible? they wanted to charge over $1000 for that