Hello, I hope I can offer you some assistance.
Can you provide a little more information on the concern? Is it that in low gears the engine speeds up but the car doesn't? Or when you stop the idle speed is high? Or you release the throttle and the engine doesn't slow as much as you expect it to? Is the car a petrol or diesel?
Let me know and I'll reply to you as soon as I'm able to.
Hello again, thanks for your reply.
If the engine races with no power when you try to accelerate then this would suggest that the clutch is slipping. The clutch consists of a plate clamped between the flywheel and the clutch cover, the plate transfers the engine drive to the transmission, as the plate wears the clamping force becomes less allowing the plate to start to spin so transferring less drive to the transmission, as you accelerate and drive isn't transfered there is no load on the engine so the engine speed increases but the vehicle speed doesn't increase in proportion to this.
If the clutch is slipping then to replace it the transmission needs removing.
I hope this answers your question but if I can assist further or if you have further questions regarding this let me know and I'll reply as soon as I'm able to.