RE: Ask the Car Guy @socky May 12

WOW. That engine doesn't even hold that much oil. It is not consuming oil. It is guzzling oil.
I assume that there isn't a giant mess from an oil leak, so it has to be going somewhere. I bet your car is smoking and you are burning that oil in the combustion chamber.

You probably have bad piston rings or bad valve guides. The valves can leak oil around the stem of the valve and into the intake. Valves can often be fixed with some small seals around the stem of the valve. This job is significant, but doesn't require a complete engine tear down.

Considering how much oil your car is losing, I suspect the piston rings are bad. The piston rings can leak combustion gas into the block and pressurize the block. This is called blow-by. All engines have a very tiny amount of blow-by and the excess pressure is vented into the intake. In your case I bet the amount of blow-by is excessive and there is a bunch of pressure being relieved through the vent. It is picking up oil and blowing it into the intake where it is sucked into the cylinders and burned.

I suspect you have a bad engine. You can have a mechanic perform a "compression test" to confirm.

If it is bad rings, the engine can be rebuilt. It is major work and requires a complete tear-down of the motor.