Please can anyone advise why the glowplugs stay flashing for about 20 seconds after startup , this has only just started to happen the car is a 54 reg , is this is a fault if so can anyone advise how to fix it many thanks .

Hi there!
you would really be better off asking these type of questions in the Doblo section.
Althought this will proberly be moved there if you wait a wee while.

Normally sign of glow plug circuit failure...prob a faulty plug.