I was driving my car tonight and it was running awesome. then I missed a shift getting onto the highway - it accelerated up to 70mph perfectly. i wanted to pass someone so i just gave it more gas but it seemed as if my speedo was stuck on 70, even though i could feel my self moving faster. all of a sudden the speedo jumped up to 75. i thought that was odd, so i got off the highway. as my car was deaccelerating i watched the speedo(using only brakes only to stop), and at almost a near stop it was still showing 20-25 mph. when accelerating the rpms will go up and the car will move but the speedo is lagging behind…even tho the car is actually accelerating. for example: matching the pace of traffic in a 45 my speedo was only showing 25…then it jumped up.
the speedo seemed to lag the whole rest of the way home.
does this sound like maybe a loose speedo cable?(i hope). or something more important like a clutch issue?
or anything else?