NHTSA Complaint #10452102 — 2005 CHEVROLET IMPALA

I'M NOT SURE WHAT THIS WOULD BE CLASSIFIED UNDER BUT HERE'S THE DESCRIPTION. THE GAUGES GO HAYWIRE, I.E. THE SPEEDOMETER JUST KEEPS GOING UP EVEN IF YOU SLOW DOWN - UNTIL IT GOES ALMOST ALL THE WAY AROUND AGAIN. IT NORMALLY STOPS AT THE BOTTOM LIKE AT THE 200 DEGREE POSITION IF ON A 360 DEGREE VIEW. THIS HAS BEEN HAPPENING ON MY CAR SINCE AROUND THE 30K MILEAGE. STARTING JUST LAST WEEK [MARCH 2012], NOW THE TEMPERATURE GAUGE IS STARTING TO DO THE SAME THING. IT STARTED RUNNING "HOT", [BUT NOT REALLY] SO I IMMEDIATELY SHUT DOWN MY CAR, CALLED MY MECHANIC, ETC. THE TEMP GAUGE ALSO WENT ALL THE WAY AROUND AND SOMETIMES STAYS THERE, SOMETIMES IT COMES BACK AROUND TO NORMAL. UPON RESTARTING THE CAR, THE TEMP GAUGE WOULD START COMING BACK DOWN IN SEGMENTS - TURNING THE IGNITION SWITCH ON/OFF WOULD MAKE THE GAUGES COME BACK DOWN TO NORMAL IN NOTCHES OR SPACED INCREMENTS. NOW I'M RUNNING MY CAR WITHOUT KNOWING THE PROPER SPEED AND ALSO NOT SURE IF MY CAR IS REALLY OVERHEATING OR NOT. *TR