An 04 tdci..

Engine's also very rattlely and smokey and was idling on 3 then after a few minutes went on 4 (I think), it's been sitting for 4ish months maybe longer, it's revs not to bad (still a lot of this smoke though) when I started to drive, when in first it hardly moved and my foot was dm near to the floor. I tried going into second, it pulled slightly better but not much

It's got a (seemingly) genuine 90000 from a mot history check, the car is general's in very good shape, just this engine problem. I though either injectors/s, turbo or seals, egr....all 3

Seller wants 600

Not hellish much happens here

Blown turbo seals? Have you checked turbo for bearing play?

I'd say turbo too.

Hellish expensive ;)

If you havent bought it, walk away! Your going to spend a lot more time and money and stress diagnosing the issue I can guarantee you that much!

My money is on the injectors. The turbo won't cause it to run on 3 and if the smoke was because of the turbo it would more than likely be blue.

As above, I would walk away.

If the oil is being vapourised and not burned the smoke will be white. The fact that it's running on three could easily be a piece of turbo has been ingested and ruined the engine.

If it's oil that's being burned or fuel?