In case anyone's interested, did my car over the weekend, replaced banjo bolts, feed pipe, sump off, cleaned out etc. Car is a 2008 90bhp with no DPF, on 58000 miles. Serviced twice by Ford at 14k and 32k with semi-synthetic, then when I bought at 46k, then 54 and 57k and now again at 58. Luckily I stock up on Magnatec when its £18 from ECP. So quite long intervals between first services and with all the horror stories I decided I'd rather replace possibly OK parts than wait for it to go bang.
I found the banjo bolt filter was fine, the feed pipe was fine, as was the return, all completely normal. Ford have changed the design of the filter - original parts have the filter in the end of the bolt presenting a small surface area, the revised design has the filter inside the bolt so there's a bigger surface area, therefore less likely to block. So a bit of a waste of time and money but at least I know what's going on under the bonnet.
As for the sump, that was worthwhile. I decided not to bother removing the pickup pick and just fired a can of brake cleaner up through the mesh in the bottom. Each shot of cleaner caused a big load of black gloop to come out. The bottom of the sump holds about 1/4 litre of oil so it ends up contaminating any clean oil that gets put in. Dunno if anyone's had success using a vacuum drainer, the dipstick tube has a couple of kinks in so it might be tricky pushing a tube all the way to the bottom. I was glad I got it all cleaned out, and the oil is still coming up clean on the dipstick which makes a nice change from it turning straight to ink.
I'll stick a how-to guide in the Guides section if I get time, there were a few gotchas and the usual "why did I start this ****ing job"
moments so it might be helpful for someone.
So the conclusion.... don't believe all the scare stories about these being unreliable engines - unless your turbo has gone bang of course :-( there must be some factor that causes the carbonisation problems, either leaking injectors, blocked DPF, poor oil servicing or a combination of the above - or who knows. The question is how would you tell if you had an injector problem or a blocked DPF before the damage gets done? I dunno if there's something an owner can do to diagnose those faults, I guess the problem is hidden away until its too late.