Overfilling, the wrong oil and excessive oil pressure are among the main reasons an engine consumes more oil than it should.
Checking engine oil has its own rules: the most accurate reading comes about 3 minutes after switching off a warm engine. If the level is low, there may be several reasons.
- Overfilling: oil above the maximum mark is whipped into foam by the crankshaft and carried into the intake manifold; keep it between the dipstick marks.
- Wrong oil: follow the manufacturer’s recommended type, SAE viscosity and API quality class.
- Excessive oil pressure: a faulty relief valve, clogged passages or overly thick oil raise pressure and force oil past seals and gaskets.
Apart from choosing the right viscosity, most of these problems must be diagnosed and fixed by a workshop.