Well the bloke Iv spoken to sounds genuine and is trying to help me out, hes sending the gearbox to Renault for them to inspect it and if they can supply the parts of the engine and the gearbox then he will put it all together free of charge. Im a bit of a rookie when it comes to the ins and outs of an engine but he reckons its why my last engine went bang. Hes adamant its a fault of the box so I guess Iv just got to let him and Renault sort it out..