The engine oil in a car engine serves several important functions. Covering the moving parts of the engine with a protective film, it significantly reduces friction and wear of parts, protects the units from corrosion, dirt and harmful deposits.
A certain oil consumption for waste and engine intake is provided by the passport data of any vehicle. The normal consumption is 0, 1-0, 3% of the fuel consumption. An increase in consumption indicates a malfunction in the engine, which can lead to serious consequences, up to a major overhaul.
Consumption per liter of oil per 1000 kilometers can be considered the norm for powerful V6 or V8 engines, for small cars this is already a significant excess of the standard oil consumption.
Increased oil consumption due to leaks
The very first reason that the engine starts to "eat" oil is a banal oil leak outside the engine. There are several potential places where oil can run out.
Leak through the oil filter gasket. A fairly common situation in which oil flows out through the oil filter O-ring. Such a leak can be easily eliminated by tightening the filter or replacing the O-ring.
Leakage of oil through the crankshaft oil seals. Most often, such a leak is associated with wear of the sealing lips of the oil seals due to their long service life or rubber and poor quality. There are often cases when new oil seals begin to leak after adding any additives and other autochemical fluids to the oil.
Leaking through the cylinder head. This is already a serious malfunction, indicating that the engine is operating in emergency mode. Such a leak can occur from overheating of the cylinder head. If the engine was repaired before the leak appeared, then the power bolts were incorrectly tightened during its assembly. The presence of such a leak can be indicated by oil stains and drips on the surface of the engine block. This defect requires immediate elimination, as it is fraught with serious consequences, up to the "wedge" of the engine or water hammer.
Engine oil system malfunctions
Another of the main reasons for the increased oil consumption is the wear of the internal parts of the engine, which are responsible for the smooth operation of the oil system.
The world's first motor oil was patented in 1873 by the American doctor John Ellis.
The most common reason for a significant increase in flow associated with the operation of internal engine parts is leakage through the valve stem seals of the engine valves. These oil seals are constantly exposed to high temperatures during engine operation, due to which they lose their elasticity and their sealing properties. The occurrence of such a malfunction is accompanied by a significant increase in oil consumption and an increase in the amount of smoke emitted. Replacing the valve stem seals in such a situation is almost inevitable.
Oil scraper rings are another important element of the oil system. Since the oil scraper rings operate in areas of high contact pressure, their wear is inevitable and is inherent in the very principle of operation. In addition, the rings can be overheated or coked, which also contributes to an increase in oil consumption for waste, and during coking, a decrease in compression and unstable engine operation are added to this.
Increased cylinder wear or warpage is the most serious reason causing a significant increase in engine oil consumption, requiring significant repairs with replacement of pistons, rings and block bore.
It is also worth noting that increased oil consumption can be caused not only by purely technical reasons associated with engine malfunctions, but also by unfavorable operating conditions. Aggressive driving at prohibitive speeds always leads to the fact that the engine begins to "eat" oil. Therefore, all experienced fans of "gas" always carry a can of oil in the trunk.
