my tahoe oil gauge needle bounces around from when driving down the road. when i am idling the gauge reads a steady 40psi as soon as i drive down the road the needle starts reading all over the gauge but never pegs out but will fall to 0 and low oil pressure will light up and then may go back up to 40psi I replaced the oil sending unit and that didnt stabilize the needle so i put a rebuilt cluster from Dorman in and a still made no difference. the oil gauge is the only gauge that is malfunctioning. I know the pressure is ok because i have made a trip of 600 or so miles on the interstate driving 70 mhp and there isnt any engine noise. the vehicle runs great!