Peugeot with I.E. dies on downhill and at traffic light

[GrumpyUnk]

Two things can cause premature ring wear, off the top of my head. Running too hot can cause the rings to lose their tension and not push outward against the cylinder wall. Both power reduction and oil consumption increase would be symptoms. Possibly hard starting due to lowered compression. The second would be air cleaner failure allowing instrusion of dust & dirt via the intake. That can cause the rings to wear prematurely. Third would be rings that have not had their end-gap checked during installation. When the engine gets to normal temperature, the rings expand and close their end gap. If not checked and adjusted as needed, they can close the gap to zero and cause all sorts of problems. Finally, running for miles at WOT and at top speed without any breaks can cause wear due to possible minimal oil and lack of vacuum to pull oil up onto the upper cylinder wall. More or less. It does not hurt to close the throttle once in a while to produce engine vacuum and give the rings a few seconds of suction more than normal(close to none with WOT) to pull somee oil up onto the rings & cylinder wall.
The Motul is considered one of the top brands of motor oil. I doubt they produce anything that would be bad for a 139QMB.
You reference 'got this fault'... What fault is that exactly as I see no mention of it. Does the engine use oil excessively? Lose compression? Produce blue smoke when running?
What fault do you reference?
tom

[GrumpyUnk]

Can you post some pictures of the valves, especially the seating area? A pic of the seats in the head would also be useful for visual analysis.
If you are keeping the valves, do you plan on lapping them to clean the valves and seats? Or replace new valves? New head? The valve stem seals are ok if they are still a bit flexible and are tight on the stem.
tom

[jackrides]

What is your valve clearance? What are the specs? How much pull do you feel on the gauge strip when you pull it thru the valve space?