TD5 oil pump failure.

[Primalanton]

Hi all! Some weeks ago I posted an item about my TD5 motor failing.
At the time a few members suggested that the oil pump sprocket bolt may have come loose.
Well, after having a replacement long motor fitted, I decided to investigate why the old motor failed after only 140,000 kms.
Yes, it was the oil pump, but no, it was not the bolt or sprocket that caused it (both were like new and tightly secured). I removed the inner & outer oil pump rotors & immediately noticed that the outer rotor was badly worn around the "internal sprocket" shape - so much so it seems to have worn out of shape up to 4 - 5mm! Everything else seemed to be in order & could rotate freely.
The upshot of all of this was the pump was pumping & keeping up oil pressure at normal operating speeds but at idle there was no oil pressure! The last half hour of the motor's running was at idle whilst I ran the compressor to inflate tyres - thus the failure!
Has anyone else experienced this problem, or have any idea of what caused it?
The car has an excellent service record & appears to have been well maintained before I bought it a few months ago.
Any help or advice would be appreciated!

[Patchy]

At a guess I would say at some time In its previous life it may not have had a good service history or even been getting filled with incorrect oil type, even tho books and paper work can show its all up to scratch this can also be faked.

the other possibility is that it has run very low on oil due to some sort of failure such as a turbo or oil cooler failure if you have paper work showing anything along those lines id be leaning that way. Being second hand it will always just be a guessing game. Good to see your all up and running again tho