dispatch 2.0Hdi Engine "Knock"

I have a 2000 dispatch which seems to be developing a loud knocking sound, top end, and the engine management light has come on. Any ideas on what this may be or how to find out what fault the management system has thrown

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.