On 09/03/2024 at 19:33, SG10 said:

Out of interest, does anyone know what the black rubber/plastic jobbie is in the base of the filter housing? 

 

I would look very carefully at that, I think it is a bypass valve for if the filter element is clogged, I think they allow unfiltered oil to pass under that circumstance but what if instead it is passed back to the sump? 💡💡

 

Its a lot easier to get at than the oil pump PRV, maybe the oil flow is described in one of the self study guides.

Thanks all for your help and guidance.  Unfortunately I can't be doing with any more time spent messing.  One of the problems with being out in the sticks is the absolute reliance on your vehicles, and the "skip" was well past its best.  As of this afternoon it has gone to a new owner for a bargain price, and he's getting all enthusiastic about messing about in sump oil, whilst 'herself will be receiving her far newer Citigo in a few days time.  Probably all for the best.

Don't blame you. All the best with the Citigo. 

Appreciated, thanks!