[mike1967]

so its a cooper s countryman will be N18 petrol prince engine and they do eat oil anyway, the oil pump is ecu controlled on that, as is thermostat ie piloted ecu controlled there is a recal on some cars for this thermo housing have seen cars getting to hot and oil suffers from it and thin out as oil is tested to 100c and prince engine runs up to 108c two things worth looking in to,
the oil usage i have seen a lot with many cars and can be down to a few things, ie like your mech says rocker cover maybe, also if engine running hotter than is good helps use oil, also timing chain stretched will cause engine to run retarded and creates more heat add all these things together and things go wonky,, also bi product of all this is carbon build up in crankcase and especially around oil control rings on the bores and also valve stem seal do to thin oil it will use oil more so, all of the above is what a typical n18 with 80.000 miles plus n18,,
i have helped the oil uses before if its only based on carbon build up by adding seafoam to engine oil and flush the system, i also then add 1/4 can to the new oil on these engines so other time ie 8k oil change next time it cleans and keeps clean,, also driving them harder helps to prevent bores from shining,, on really bad ones have put 5/40w ie a thicker oil at 100c in and that has improved things,, this all said i would seafaom it and drive it for 30 miles the first time before dropping oil and add 1/4 can to new oil maybe run it for 1k harder see if that sorts it,, worth a punt if engine is not worn out or course

 

[mike1967]

Many thanks, I will share this with the Mechanic...

i'm also time served tech he will understand what i wrote and how those engine behave,

 

[mike1967]

Look at this video. It tends to diagnose your exact issue starting with the oil filter housing and then going to the timing chain and oil pump chain.

wow i have heard it all now total rubbish talking total balls, on that link, just the kind of garage you would avoid like the clap. water pump tensioner has no bearing on oil system nor dose belt unless car running hot from faulty water pump or the coating has failed think in the 10 years i have been working on these engines only ever seen one jockey wheel failure on a 160k car, , the oil pump chain if were snapped or were slipping over the teeth would have a bearing on it, that chain is normal for a 60.000 miles prince engine the teeth on sprockets look fine ,, timing chain has no bearing on oil pressure unless the idle of the car has fallen below the min revs the oil pump needs to maintain pressure on idle that said i have replaced thousands of chains over the years where they were running badly but oil pressure was still there and fine as the oil pump runs off the end of crankshaft via the small chain etc,
most likely is oil over heated from bad coolant system, or some time in its life was run low on engine oil as some people think the oil should never be checked foolishly, also using wrong oil or just plain been hammered for most of its life and is worn out,
no disrespect t towards you mini is 4 me just the link will mislead people and they might spend a lot more money than whats needed to, and the fact the guy said he had to contact main stealers who still denies mini has any issues to be honest,

 

[mike1967]

good question dont know on n18 not done one like that always been a cover,

 

[mike1967]

common is pcv valve as you have done, also oil filler cap rubber seal can leak best checked in dark with a torch, also the breather pipes can crack,, on n14 turbo engines it was common for oil to build up in the bottom of inlet manifold when not being rev'd and when rev'd later would get sucked in to number 1 cylinder inlet port and cause piston detonation ie it brakes apart and cat gets blocked with burnt oil, just had one with 58000 miles do this trick as well as stretched timing chain, the later n18 do same trick but have better piston rings i believe. this all said bmw say 1 litre of oil to every 1000 miles give or take 200 miles is normal in their eyes