Does your engine have a centrifugal oil filter?
If so, every time your engine has an oil change, the centrifugal oil filter paper element MUST also be changed.
What happens if it isn’t?
We found this during an overhaul of an engine here in our workshop.
There was no paper element in the filter and as you can tell by the amount of carbon that we removed, it has been a long while since it was inspected!
The purpose of these centrifugal oil filters is to prolong the oil life by removing carbon.
Forgetting to do such a simple, and low-cost step can cause carbon buildup to solidify. This then leads to sludge in the sump and damage to bearing shells, and eventually, engine failure if left for prolonged periods.
If you have any doubt as to whether yours is due a change, check the colour of your oil: the blacker it is, the more overdue the filter change is.