JohnF. You must realise by now that you are the only person on this planet that thinks its a good idea to go 11 years without an oil change even when you do a low mileage.
Me too!
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If you have a poke around on the Bob is The Oil Guy US oil-obsessives website you'll find quite a few others, along with many accounts of long-extended oil-change intervals, indefinate shelf life, and a notable lack of any evidence to the contrary.
Quite so. I have searched for such evidence and found none.
I think I'm on about 5 years on the current fill. I might change it fairly soon but my concern is accumulated wear metals (which MAY be a particular issue with this engine) rather than oil breakdown.
I don't understand your concern re 'accumulated wear metals' . I have never read of galling (the technical term) being a problem in the pressurised filtered lubrication of car engines. I suspect it dates from steam engine days.
I think galling only describes one particular wear form, though I'd have to look it up to confirm that.
Clearly wear and metal particle production happens in all engines, but it'll be related to mileage so won't be a particular problem in low mileage cars.
I THINK it MAY be a particular problem in mine because I noted what looked like metal on the upper side of the dipstick after a long stand while I was back in the UK. A magnetic pickup tool down the dipstick hole picked up what SEEMED to be a lot of fine ferrous metal slurry, but I don't have quantition of that, or any real standard of comparison.
I dropped the sump (a pain on this car) a couple of times on short oil change intervals, and MAY have got rid of most of it, but since I've never worked up a way of quanifying it I can't be sure of that.
The sump seems to drain poorly, which may be part of the problem, if it is a problem, and theres a minority view that the cams look rough, though most people seem to think they look OK.
It was dealer maintained by the book by the previous owner, which may have meant that the oil was drained cold and perhaps not for very long.
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