When I'm driving along my engine revs are twice as high as they usually are but my car doesn't pick up any speed. The thing is that I have no problem selecting or changing gear. Has my clutch gone or does something just need adjusting?
Sounds to me like your clutch is slipping, It may be possible to adjust the clutch cable ( some are adjustable ) if not then you will most likely have to have a new clutch.
What type of car do you have? Some cost a lot more than others for spares plus it will depend on where you get it repaired, Clutch change for a front wheel drive car is about 6 hours labour so even at a relatively cheap £60 an hour labour charge you are already over £350 without parts and VAT!!
They are not that bad to do Myriad, check out prices on Ebay for the full kit! Bearing / Clutch ( Spinner Plate) Pressure Plate, do not be tempted ONLY TO REPLACE one of the 3 components.
Quick search around the Nottingham area shows replacement with parts at around the £450 mark for your car. That is the average price though so a bit of shopping around could save you a fair amount. Just be careful if you do need to use your car before getting it fixed as the heat build up from a slipping clutch can damage the flywheel and that would push prices even higher.
TRANSMECH Clutch Kit (3 Piece) for Renault Scenic, Mega...
Brand New and In Stock for Fast, Free Delivery!
Express delivery available
£74.76 Free
This is the price off ebay Myriad, but as Tony has said, DO NOT GET IT DONE BY THE DEALERS OR K.F. with the latter they will tell you the car needs a new body.