Well I have just read the Api list of things that must be done, to ensure that turbo failure does not re occur.
What seems to be the obvious cause to me apart from poor maintenance , and/or owner apathy to servicing schedules, is that EGR is one of the main issues with these engines. I have a C3 1.4 HDI, and this has done 300, 000 miles, just clicked over last week, and this is on its origional turbo.I believe this is mainly due to the blanking off of the EGR at about 50000 miles. The engine is as clean as a whistle inside.
Those horrible pics of the inlet manifold are due to pollution by the EGR and nothing else.
When we change a turbo on a 1.6 hdi, we remove the sump and check for all the issues pointed out, but in most cases the oil feed pipe will be blocked solid by the little strainer gauze at the engine block end.
It seems bizarre to me that this gauze is fitted at all, as it would take just a few fragments to block it up, and they are always blocked!
We simply remove this gauze, and refit the pipe (after a careful clean), and this does the trick.
Now maybe a few engineers will tell me this is not acceptable, but I can assure you it works for me, my theory being that some dirty oil is better than no oil.
I assume this is why we are being directed to replace all the banjo bolts at every service. If your car has a dpf this is going to be very expensive as the lower fitting cannot be removed with the dpf in place.
We have found that if the engine is cleaned well with the sump off, all injectors sealed properly, and the inlet manifold steam cleaned out, banjo gauze removed, problem is solved so long as the oil is changed regularly and with a good quality full synthetic.
The vehicles with a dpf are more affected, as the extra heat build up from this getting blocked just exaggerates the problem. In an ideal world, block off the EGR valve, delete the DPF, and the car will be all the better for it.
Just as a side note, my local factors approached me regarding how many repeat failures I had suffered with these turbos ? My answer was none, they admitted to withdrawing the unit from sale, as within 1 month, they had received 29 returned units out of 50 sold
, so that is a lot of garages not reading the instructions about reasons for failures.