Why does the engine speed increase but the vehicle speed doesn't?
2 Answers
The reasons why the engine speed increases but the vehicle speed doesn't are as follows: Transmission slipping: Transmission slipping may be caused by issues with the hydraulic fluid level in the transmission. If the fluid level is too low or too high, it should be adjusted accordingly. After adjustment, check whether the transmission still exhibits slipping. If slipping persists, the quality of the hydraulic fluid should also be inspected. Clutch or brake wear: If the hydraulic fluid appears brownish-black or has a burnt smell, this phenomenon occurs because the friction plates of the clutch or brake have burnt. Additionally, based on the oil circuit pressure, corresponding inspections and repairs should be carried out on the oil pump or valve, and the transmission's sealing rings and gaskets should be replaced promptly.
Last time my car had the same issue, the engine was buzzing but the speed wouldn't increase. I drive a manual transmission, and later found out the clutch disc was worn too thin causing it to slip. The mechanic said this situation is particularly harmful to the car because the engine power wasn't being transmitted to the wheels at all. For automatic transmission cars, it might be a transmission problem, like insufficient hydraulic fluid or a broken torque converter. Also, a seized brake caliper can make the wheels feel like they're being held back and unable to move. If it's during rain or snow, heavy throttle might cause wheel spin and slipping. I remember that time I stubbornly drove home, and ended up spending nearly two thousand more on repairs. My advice is, if you notice the RPM and speed don't match, pull over and check immediately—don't be like me and keep pushing it.
