It is quite a common failure, you need a counter hold tool that goes inside the centre of the pulley to hold it while you undo the bolt. Get a new bolt kit and there's a diamond coated washer behind the pulley which MUST be replaced. The torque setting for the bolt is very large but it must be tightened properly, requires a 3/4 drive socket set and a length of scaffold pole, rattled up as hard as it will go with an impact gun is no use! If it comes loose it will chew the crank key and timing belt sprocket with potentially disasterous consequences. Are you sure you're looking at the timing belt? It's got some tin covers over it behind the crank pulley?

 

Thanks for that . Yes definitely the timing belt the ribbed auxhiliary belt is in front of it on the crank pulley .it looks like the back of the pulley has rubbed on the timing belt . Again is that normal ?

 

It can happen if the pulley is goosed mate.
I'd not just change the pulley but the timing belt & tensioners whilst you have the pulley off.
The most important thing is make sure you get that diamond cut washer from vw.
Re-use your old one and the timing can slip & the whole engine can be written off.

 

Sounds like good advice to me at least it didnt affect the timing apreciate the help . Looks like I will be doing my first cam belt change A:

 

job is now done and fortunately the only damage was the crank pulley and timing belt A: from all accounts a very lucky chapi .Soo glad my pride and joy is back in the land of the living . Quite shocked to find that there is a date stamp on the pulley and it's the original 1996 one . Fair play its lasted well . Also found that the person that changed the timing belt last had put the diamond washer on the bolt and not behind the pulley :*