Believes it has to do with the transmission, 3rd gear. when going over 30 miles per hour the engine revs
My car has 21000 miles.
My car has a manual transmission.
Hey there. It sounds like your clutch may be worn to the point of slipping. The engine revving but the vehicle speed not matching in 3rd gear is typically an early indication of the clutch being worn. When the clutch/pressure plate assembly gets to this point, it no longer has the clamping force to transmit engine power to the transmission. It may soon get to the point that it will slip starting from a take off in 1st gear and/or not being able to move the shifter at all when the engine is running. Have a certified technician inspect your clutch operation as soon as possible so that this can be corrected.