Recently my engine revs at the bottom of all gears except 1st (manual) without any significant increase in power to the wheels (speed), but the revs eventually normalize (drop and increase slowly with power/speed going up) if i keep pressure on the gas, or if i release pressure on the gas and increase slowly. I have no idea what it is, but it gets more frequent as time goes by. Any clues?
btw its a 98 civic HX manual trans.