53 plate Freelender TD4 running problems

Hi , I am having difficulty locating the source of the problem i`m having on a freelander , 53 reg 63.000 miles, It has the TD4 engine fitted , The problem is when your driving is sort of surges as if it is running out of fuel , I fitted a new fuel filter approx 4 weeks ago and have covered approx 1500 miles since then so I know it is not the cause of it . When it surges the engine makes a rattling sound momenterily then picks up on off it go`s again, This happens roughly every 5 minutes . there are no codes present . I have had it to our local Garage and sods law it never happened when they had it . It was ok for a few days after that but the problem is back again ...... Any help would be most greatful ....... Thank`s . Oh forgot to mention when it surges/rattles there is no smoke or Anything coming from it . ..

No codes? Were they using non Land Rover diagnostics?

I'd suspect the fuel pressure regulator at the end of the rail. There is a new sensor and loom available to fix this issue, but it would help to confirm things if T4 or similar was used to read the codes.