2006 1.6 Ti-VCT woes...

I've been away from the forum for a while (again!), and even when I was here this engine was not of interest because I never planned on owning one.

Technically I never have owned one, but my mother does and therefore I'm responsible for it.  Makes sense if you know my mother!

Anyway, she bought it with 170k on the clock (mostly long journeys) towards the end of last year and since then it has been a good car.  Got through the MOT with no welding (shock horror) or any major repairs, so decided as it has a clean body (intact front wings) and undercarriage to try and preserve it for a few years.  As a result today it went in for a new timing belt/water pump/thermostat and underseal. 

All great except the slight rattle for a second or two on cold start up I'd heard and written off as lifters, the mechanic thought was a "dephaser" and having googled it, I think it probably is also.  I think they are also referred to as a cam variator.

Apparently Ford are the only source of a replacement, which is close to £300.  My mother in her wisdom decided against this which given the value of the car already being outweighed by the pre-arranged job, I can understand. 

I suspect if that is the problem, which is almost certainly is, then it was caused by poor maintenance as when she got it the oil was black, which never bodes well.  That's also why I wrote off the rattle, which I thought would go away after changing the oil a couple of times and perhaps flushing it on the next change.

So after writing an essay as I usually do, I have 2 questions for those more in the know than I.

1. Will using engine flush, then changing the oil and adding a valve/lifter additive perhaps help at least preserve the failing part?
2. Is there a cheaper source of the "dephaser" for replacement at a later date?
3. Also (I know 3 is more than 2) does anyone have an idea how long the rattle lasts before it "goes", and when it does is it a case of valves hitting the pistons or just running very poorly?

If anyone recalls my last posts, they were around her previous Focus, a (same year) TDCI, which after some chaos replacing the fuel filter, promptly broke down from a failed high pressure fuel pump.  That was scrapped as the cost would have been more than it was worth, plus it was slightly rotten.  Although in hindsight I'm wishing we'd spent the money on that instead 🤣