What are the causes that makes an automobile engine to burn oil?

Mick is correct, Rings , filters not allowing crankcase pressure relief or valve seals. Valve seals go bad from valve guides being worn out and from simply decaying and rotting from age.Hey everybody- it's VALVE SEALS not VALVE GUIDS !!!!!!!!!!!!!!!!!!What are the causes that makes an automobile engine to burn oil?
Worn piston rings


Pisons


Worn cylinder block


Worn valve gides


Cracked head


Have a compression test run then go from thereWhat are the causes that makes an automobile engine to burn oil?
bad valve stem guides. bad piston rings. bad head gasket, cracked head, lots of reasons. have a good mechanic look at it.
A problem with the coolant system is the main cause of burning oil. If your radiator is emtpy or your fan is not working properly, your engine will quickly heat up so much that the oil will start to burn.





Obviously a leak will cause the oil to spill onto places where it can burn also.
bad cooing system, bad piston rings...to many to name
many things can cause it to burn oil, one, the piston rings are bad, two, you have rough cylenders caused by dibris scraping little canals in the metal, three, the valve guides are dry and cracked causng oil to leak into the combustion chamber, to fix it, take it to a mechanic, if your a do it yourselfer thats a tough one, if your rings are bad you would have to remove the oil pan and the head, to remove the pistons, if you have a screwed up cylender, you have to get it bored out, by a machine shop, and get oversized pistons and rings, if its the valve guides you have to drill the guide out and replace it with a cover, all of theese are advanced and should just be taken to a mechanic.
Bad head gasket


Bad piston rings
Usualy wear in piston rings valve seals blocked vent filters not enough info to help more .Regards mick
bad rings ,bad valve seats