@vaqas1
I agree with you that if the head or cylinders are in bad shape, then changing just the rings (or other things) will not do the job. But this does not proves the fact that charade diesel engines are not capable of performaing good after 2nd overhaul. I might be mistaken but if you know any documented proof of this fact, as you mentioned earlier (Charade diesel already known for short engine life plus un reliable type of engine), can you please provide the link/doc here so that all other members can also read it.
I cannot take the so called mistrees experience as an argument. I personally kept charade diesel for over 13 years with diesel turbo engine and i overhauled it personally and had absolutly no problems with the performance.
The fact is that mistrees do the overhaul as part of thier job and cannot invest extensive amount of time in each car (atleast in pakistan) so they dont go in details. For example the most common problem of diesel engine and specially charades engine according to mistrees is so called ENGINE KI KARAK (it is said normally that if you overhaul the engine, engine ki karak nahi jati....), but i guess no one or atleast very few people know the reason behind it. Its because of the tappets of the engine, in petrol engine you can adjust the tappets through adjusting the tappet screws, but in diesel engine there are no screws on tappets, rather there are spacers on the tappets. They have different thickness and it can normally be seen written on each spacers. After overhauling the engine and specially head (getting new valves and making new valves seats), obviously the displacement of each valve no longer remains the same, and when the old spacers are used without measuring the required amount of tappets, obviously the KARAK sound will come. I personally did this experience and adjusted each tappet using the correct spacer with required thickness, there was no karak sound at all.
so i guess it is not correct to say that these engines are known for short life etc. If the overhaul is done correctly then it doesnt matter if you are doing it 3rd time or 1st time, it will work and it works...