Do A compression test and a leakdown test too, This will tell you if you have A internal leak. The compression and leak numbers are not nearly as critical as the numbers being within 20% of each other across all cylinders.
A compression check and cylinder leak-down test should tell you the condition of your engine.
A compression test.
Find the leak and repair it with a compression or push-in fitting.
That isn't much consumption.. If it buggs you take it to a garage and have them give you an estimate.
compression test or leak-down test.
Have a compression test run. This will tell you allot.
A compression test will determine which cylinder(s) are at fault.
If no visible leak is found then turn on the heat on high. A slight sweet smell indicates a small heater core leak that does not show a visible leak. Look at the oil dipstick. If the oil is frothy or milky colored then the coolant is leaking into the oil. Check the engine compression. Low compression can be a blown gasket causing coolant to leak into the cylinder.
Cylinder bleed down.
pressure test the cooling system
White smoke from the exhaust is a sure sign of a blown head gasket. You will also be loosing coolant with no apparent leak. A compression test will verify this. A rod will knock if the bearings are worn.