right i have an sdi octavia 2003, the problem is at idle there is a sort of squeal comes from the engine but to my knowledge this is not from the fan belt but it is from that area?? it happens around 1000rpm whether the car is hot or cold! can anyone shed any light on this?

Had this on a 2 litre, it turned out to be a seized water pump, which stripped all the teeth across 90% of the width of the cam belt. Amazingly the timing didn't jump and the valves didn't make contact with the pistons, however the engine was scrap 6 months later when it was driven with a hole in the sump.

Take the belt to cover off look for debris and feel the underside of the belt. Hopefully this won't be the problem with yours.