My Vauxhall Corsa has just had a new started motor, distribution box and leads, yet will still not start?

Put the key in the ignition|||Check the teeth on the starter flywheel ring gear.The part that the starter engages with to turn the engine over.You may find that the teeth are worn out.The noise you describe is very much like that noise which occurs when the starter bendix grinds with the teeth on the starter ring gear.If that is the trouble the gearbox and clutch assembly will need to be removed to change it|||need more info other than dont start does it turn over does it try what happens could be dirty battery cables or a bad coil no gas no spark need more info|||Could be your battery and or alternator as well.|||starter motor not aligned properly or duff starter|||Charge the battery - if it wont charge buy a new one