Engine oil consumption is a problem nobody wants. Most new engines today use less than half a quart of oil in 3,000 to 5,000 miles.But as the miles accumulate, wear and oil consumption naturally go up.
An engine that burns oil will usually foul the spark plugs.That,in turn will cause ignition misfire, higher emissions and likely damage the catalytic converter.Also,an engine that is burning oil usually won’t pass an emissions test because of elevated hydrocarbon (HC) emissions.
High oil consumption due to burning will also shorten the service life of the oxygen sensors and catalytic converter, even with today’s low zinc-phosphorus motor oils.Phosphorus will contaminate these parts and cause the O2 sensors and/or converter to fail
If an engine is using oil because of leaks (valve cover gaskets, oil pan gasket, crankshaft end seals, etc.), the problem can be fixed by simply replacing the leaky gaskets. But if the oil consumption is internal, major engine repairs may be required to fix the problem.
Below are some of the reasons for Engine Oil Consumption
1)Engine design: Some engines consume oil by design. From day 1,The consumption can be as high as 1 liter per 1000 kms (cca. 1.7 quarts per mile).This depends on the make and model of the engine.
2)Driving style: RPM affects oil consumption:The higher your usual RPM is the more oil will be consumed. That’s because you put extra pressure on the seals and gaskets and some of the oil finds its way around and gets burned away in the combustion chamber.
3)Seal and gasket condition:
The more worn they are the more oil will be consumed. What happens is that the oil finds its way around the seals and it gets burned away in the combustion chamber or it simply leaks out.
4)Higher-than-normal engine temperature: The hotter your engine runs the thinner your oil will be. Once again it will be simpler for a thin oil to reach the combustion chamber and get mixed and burned with the fuel.
5)Too-low viscosity motor oil: If you use an oil with a viscosity below the recommended by the engine manufacturer than you will experience oil consumption.By viscosity I do not mean SAE viscosity only. The HTHS(High Temperature High Shear)viscosity also counts.
6)Low quality motor oil with high volatility:
If the oil’s volatility is very high than it could be noticeable in the oil consumption rate.
There are also numerous other reasons including but not limited to high oil level,the damage or clogging of different engine parts,Worn or broken piston rings,worn or damaged camshaft bearings,worn or damaged connecting rod bearings,clogged “PCV” valve and the fuel contamination of the oil.