What is the reason for the high engine speed but inability to accelerate in a Mercedes-Benz C-Class?
3 Answers
The reasons for the high engine speed but inability to accelerate in a Mercedes-Benz C-Class include: insufficient oil pressure, poor oil pump performance, clogged fuel filter or injectors; partial blockage in the exhaust system; electrical circuit open or short circuits, poor conductivity, etc. Solution: Check the hydraulic fluid level in the transmission. If the level is too low or too high, adjust it accordingly, then observe if the transmission still slips. If slipping persists, inspect the quality of the hydraulic fluid. If the fluid appears dark brown or has a burnt smell, it indicates that the friction plates of the clutch or brake, or the brake band, are burnt. In this case, the transmission needs to be disassembled and repaired. Precautions: If the engine speed suddenly increases when the automatic transmission shifts to a certain gear, but the vehicle speed does not increase accordingly, it indicates slipping in that gear. The easier it is for the engine speed to rise during slipping, the more severe the slipping is.
Last time I drove a Mercedes-Benz C-Class, I encountered this exact situation - the RPMs skyrocketed when I floored the accelerator, but the vehicle speed just wouldn't increase. This usually indicates the clutch or transmission is slacking off, especially common in older vehicles. For automatic transmissions, it's likely a torque converter issue - symptoms like this occur when the lock-up clutch slips. With manual transmissions, the clutch disc might be completely worn out and needs immediate replacement to prevent engine damage. Another possibility is overdue transmission fluid change, where thickened fluid interferes with gear shifting. The most dangerous scenario would be a clogged catalytic converter causing exhaust backpressure. I recommend first reading the trouble codes. If no warning lights are illuminated on the dashboard, there's an 80% chance you'll need to remove the transmission for inspection.
Does your Mercedes C feel like the engine is roaring but not moving? I often see this issue during repairs. If the transmission fluid needs changing, it can slip, especially during sudden acceleration when the RPM surges to four or five thousand, but the car crawls like a snail. If the gear shifts are particularly jerky, it's almost certainly a transmission problem. Another common pitfall is an air intake system leak—those aging hoses can leak, and if the ECU detects insufficient airflow, it won't deliver full power. Oh, and check if the air filter is clogged black—half a year without replacement can suffocate the engine. Also, poor-quality gasoline from certain gas stations may cause incomplete combustion, so try a reputable station next time.
