I have a lupo .1.4 16v which we thought the release bearing had go on as it was making a whining/grindy sound with the clutch pedal up but would stop when down . Just had the engine out . New clutch release bearing and p plate . Also a new cambelt kit . Engine is now back in . Running fine except that sound is still there but goes when the pedal is down would I be right in thinking its the input shaft bearing ?

To check, start the engine and put it in gear if the noise is there under these conditions, it is likely to be from the spigot bearing in the flywheel.

If the noise is there when it is out of gear and you foot is off of the clutch, it could be from the input (first motion or primary) shaft bearing, but there is a VERY slight possibility that it is from the spigot bearing between the input shaft and the output (main) shaft. You MAY be able to hear this if you VERY carefully, coast it down hill without the engine running and the clutch pedal down.

NOTE: That I said VERY carefully - the brake servo won't work and you will need the ignition switched 'on', or you won't be able to steer it!!!

Take care then.

Regards.