Engine re-timing question.

[OM2]

I've had a new turbo fitted.
I've had to have the engine taken apart and have many other things checked and replaced.

I have 2 mechanics working on the job.

One said that I will need a special set of tools to get the engine re-timed.

The other mechanic has said: no need... he knows his trade well enough to do the engine retiming himself without the need for any tools.

I'm not an expert so have no clue.

Retiming an engine: what's involed?
Can it be done without the tools?

Thanks.


OM

[OM2]

just to confirm: I have a 320D automatic, 2003 model.