hope the problem has been sorted out for you now mate but if not its one of 3 things.
the first one is a tdc sensor, top dead centre!
sencond might be the cam shaft sensor or the third thing which you dont want is the camshaft difuser, this is bad news and will cost a fair few hundred from a garage the other 2 (tdc and camshaft sensor) are cheaper ranging from £80 to £140 depending where you go.
only trouble is that its they will try the two sensors first and if its not that then you've probably gonna be spending close to £700+ for all 3 to be sorted.
fingers crossed for you its only a tdc sensor. how do i know all this? ive had the same problem with my 03 megane. i love my car but i'd trade it in for something more reliable any day.
cheers cheers Benny
Ben
June 2008