Thanks for your replies.
> Normal Bloke, I ended up with a second hand filter because the jeep went in to have something else done and they discovered the filter had come away from the bowl - they are also a jeep scrap yard so put a second hand one on without asking me, then charged me 40 quid for it. Not sure if that was a good price or what have you but jeep's been running really well until 3 days ago.
They also replaced the spill rail pipes (as I didn't even know what they were until now as it's my first diesel) so now I'm wondering if they put good pipes on or not.
>The Smiths, so if I disconnect the outlet from the filter and turn it over, should it spurt out diesel from the filter outlet? (It doesn't). Also when you say "spill off pipes" they are the rubber pipes connecting across the tops of the injectors returning the unused diesel? And also when you say " the "new" one being faulty/letting air in" do you mean the new (second hand) filter?
Where should I go from here?
Sorry to sound thick, this is my first diesel and first jeep.
Thanks for your help