You can put inoil addatives {like STP} to help them last. There is also a thing called "Overhaul in a can" which I have used with limited success.
Worn engine rings or valves Worn engine rings or valves
Worn engine parts. Rings, bearings, etc.
worn piston rings
It is time for an engine overhaul. The pistion rings/ oil rings and compression rings are either broken are worn out. That is called blow-by. Your engine is done.
Possibly worn cylinder bore(s), or worn out or broken piston rings.
Your engine is burning oil. The usual causes are worn out valve guides and seals, broken piston rings, worn rings and scored cylinders which all amounts to an engine overhaul. If you have a turbo charger on your vehicle, it may have gone bad.
The typical causes are worn piston rings or valve guides.
The piston rings may be worn out .
Worn piston rings.
"Blow-by" is not good for any engine. It indicates worn internal engine parts (rings)
Worn cylinder bore, worn piston rings, poor valve seat condition, tired valve springs.
burning oil is caused by worn and broken valve seals,or worn or broken oil rings on the pistons