Ford: escort 1800 diesel very noisy

hi
My local mechanic changed the water pump, cam belt and pump belt on my
'94 escort van today. When he returned it, the engine was extremely
noisy (knocking loudly). He suggested I get rid of the van asap as the
engine is shot.

Now this engine was not making this sort of noise before having this
work done, and a friend has suggested that the injection timing could be
out, causing what he called "diesel knock".

Could he be right. If so, how do I remedy this.

Many thanks for any help

Steve L

Hell... I think I want to see an Escort VAN!