Does sound suspicious.
I think the only thing that could posssibly happen with the fuel is that the actual bore wall and piston crown could wear away due to the fuel being under such high pressure. But, i'm sure that would have been considered anyway. Thinking more, the spray patten would be of a mist and not a direct squirt so it's really quite unlikely. Also by it's own nature diesel is a light lubricant (heavy oil) so bore wash as ocurrs in a petrol.... well er can't.
In fact having thought a bit more, if anything, a PD should outlive a standard diesel and here are my thoughts :-
1, There is not a complex pump and timing arrangement to go wrong as on a normal diesel.
2, The added torque means less need to rev as high = longer life (jabba'd / revo'd excepted here of course)
3, The fueling / timing can be much more tightly controlled on the PD than other diesels which should lead to the engine running within safe 'limits' compared to a normal diesel.
However things are not all good, problems I can foresee that will send PD's to the breakers in years to come are (and they are not all engine related) are (note most of these are 'do-able' as a fix but would be un-economical in my opinion when the cars are old) :-
1, The turbo with it's integral variable nozzle system will be very expensive to replace if it fails.
2, The EGR system lets loads of goo build up in the inlet tract, have any of you taken off your intercooler hoses and seen how much 'residue' is in there ? I think this could be a cause of nozzle failure in 1, above ?
3, The goo in 2, above could cause, in time, the intercooler to clog ?
4, The unit injectors, god knows how much to replace and at this time there doesn't seem to be any DIY info on fitting these.
5, Timing Belt... snaps and engine is dead ! Again little or no info for DIY.
6, Airbags. minor shunt and airbag goes off, hundreds of pounds to replace. And if they are fitted they must funtion for MOT.
7, Other electronic components, same as airbags, cost loads and therefore would be un-economical.
8, Coolant cavitation. Heard a lot on this, basically what happens is that due to the pressure waves within the block / head as the engine is operating, air bubbles form from the coolant in certain hotspots in the engine, these bubbles are super-sonic in speed and can quickly errode metal. A real but little known problem, but do a websearch on it, you'll be horrified. Cure is to change your coolant and not just leave the G12 in for 'life' as VW say....
Generally though, like anything I reckon the PD should be just as durable as any other engine if not more so, you just have to take care of it. Again some more thoughts on maintenance :-
1, Change oil every 5000 miles without fail. Even though oil can go 10,000 or 20,000+ (in long life). In a diesel part of the oils job is to hold in suspension the soot particals from the piston blow-by gases (hence black oil). Now I don't care what anyone else thinks, but i'd rather dump the oil and get rid of all that scratchy soot before it gets a chance to really build up. I am aware that the oil itself is still fine and will not break down as old oils did, it's just I don't want soot scratching away.
2, EGR gases, i'm looking to turn my EGR down (via vag-com when I can work out how) as far as possible to stop the goo and would even consider a way of loosing it altogether so long as I could ensure that all the crankcase gases are purged.
3, Possibly looking at cleaning / washing out the intercooler at say every 20,000 miles. That goo that I imagine sitting in the bottom of the intercooler really does bother me and if the amount of goo that was sitting in the top intercooler hose is anything to go by, there will be loads. I'm going to keep an eye on it for now but would seriously consider washing it it out at 100,000 miles (i'm currently at just over 80k.
4, Fuel filter / Air filter. Change every 10k.
Other than that, there is not a lot else to do except keep an eye on your brake linings....
I do about 30k a year and have covered a little over 10k so far in my PD 115. So as I plan to keep the car for 3 years + , i'll be looking AND expecting to do upwards of 160,000 miles. AND i'm sure it will. P.S. I've done this with my two previous cars, both Fords, sold them both with 150k+ on the clock and still going strong, maintained by me, using the service intervals as above. The Golf is a much higher quality piece of kit and i'm sure it'll have no problems at all....