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High engine oil consumption causes, consequences, diagnostics

Increased or high oil consumption in the engine is a common phenomenon and therefore causes the interest of most motorists. First, everyone is interested in: what is considered an increased or large oil consumption? Then: why this oil consumption? And the last question: what to do?

Increased or high oil consumption in the engine is a common phenomenon and therefore causes the interest of most motorists. First, everyone is interested in: what is considered an increased or large oil consumption? Then: why this oil consumption? And the last question: what to do?

Let's start to learn about this:

What is considered an increased or high oil consumption?

For most non-forced and medium-forced engines (the ratio of power to the working volume of the engine is no more than 70-75 HP/l), the normal oil consumption is considered to be such that the oil level in the crankcase during its service life decreases from the upper to the lower mark of the dipstick. High-powered General-purpose engines (not sports) are designed to preserve an acceptable resource in order to improve the lubrication and heat removal of key parts of the Cylinder-piston group (CPG), which is accompanied by increased oil consumption for carbon monoxide. For example, for most V6 and V8 engines, the manufacturer allows oil consumption for carbon monoxide up to 1 litre per 1000 km. That is, for 10.000 km, 10 litres of oil, which is 1.5 - 2 times more than the volume of oil in the crankcase. In fact, the automaker is hedging its bets.

Oil consumption for carbon monoxide (oil burning) strongly depends on the operating mode. Engine operation in modes close to the nominal value is accompanied by a multiple increase in oil consumption. Urban operation cycle with frequent engine braking leads to" sucking " of oil through the valve guides. Therefore, if you operate the engine on one of these or mixed mode, then you will get 1 litre per 1000 km, and if more than a moderate suburban ride, then you can get 0.1 litres per 1000 km.

High or increased oil consumption can occur for the following reasons:

  •  Low-quality oil;
  •  Increased CPG wear;
  •  Loss of mobility of oil rings;
  •  Non-working oil-removing caps;
  •  Crankcase ventilation system is faulty;
  •  The leakage of the oil through the density;
  •  Oil discharge into the exhaust pipe through the turbine;
  •  The release of oil in the cooling system.

Low-quality oil can be an outright fake, starting from a mixture of mineral oils without additives, and up to replacing the brand with a cheap commercial product. Also, the oil may not be correctly selected for a specific engine, environment, and operating mode. As a rule, the manufacturer gives regional recommendations for the use of oil, and, as a rule, its own brand. You can use oil of the same quality and cheaper, but you need to be sure of the supplier or take the oil for analysis.

The range of oil consumption for a serviceable engine with different quality oils can be very wide. But the main thing here is not even the consumption of oil on the fumes, but the consequences of operating the engine on low-quality oil. Poor-quality oil can not only burn out faster from the cylinder walls, but also leave more carbon and varnish films that appear from increased destruction (destruction) of the oil. Low cleaning and dispersing properties lead to poor removal of carbon products from the friction zone and increase the abrasive wear of friction parts. And low alkaline and anticorrosive properties lead to intense corrosion wear. As a result, there is a second and third reason for increased oil consumption. And this is also due to the fumes.

Increased wear of parts of the cylinder-piston group affects the increase in oil consumption for carbon monoxide, mainly due to an increase in the gap of the oil-removing rings in the piston groove. Other CPG factors while maintaining the mobility and elasticity of the rings are insignificant. A large gap in the groove allows the oil to be pumped as a volumetric pump. When the piston moves down, the ring removes the oil and passes under it. When the piston moves up, the ring rests against the lower edge of the groove and pushes the oil up from the back wall. A portion of oil is ready to burn. If the oil is burning intensely and the carbon deposits are not washed off or removed from the parts of the CPG, sooner or later the rings will "Cox". At the same time, they cease to perform their functions: compression – to provide the necessary charge of the oxidizer in the combustion chamber, oil – removing-to remove oil. At what, first oil-removing rings – will be not flexible anymore, since the carbon here is more "greasy".

Both of these processes of intensification of oil fumes (wear and "coking") cyclically worsen the engine operating conditions up to a catastrophic state when the engine does not start or the valves burn out and part of the cylinders does not work. During operation, the oil-removing caps (valve seals) are exposed to temperature, which leads to loss of elasticity. In addition, abrasive particles in the oil (carbon from carbon deposits) wear out the sealing surfaces of the caps, as well as the guides and valve rods.

Thus, the resource of this unit is highly dependent on the operating mode (engine overheating) and the quality of the oil (anti-wear properties and abrasive wear). Any crankcase ventilation system, regardless of design, must provide an acceptable concentration of broken exhaust gases in the crankcase in order to protect the oil from oxidation and contamination, and reduce the pressure in the crankcase to prevent oil from being forced through the seals.

Crankcase gases also produce oil vapours, the concentration of which depends on the oil temperature, that is, on the engine operating mode and the efficiency of oil cooling.

Oil vapours linger on the oil collectors and flow back into the crankcase. During long-term operation of the engine with dirty oil and with a large breakthrough of gases in the crankcase, the surfaces of the oil collector are gradually polluted with a mixture of incomplete combustion products, carbon deposits, deposits, elements of oil destruction and other precipitation.

Despite the increase in the flow rate of gases and oil vapours with a decrease in the flow section of the oil collector, the efficiency of "rebound " of the oil is reduced. This is due to the fact that the principle of oil recovery is a sharp reversal of the flow on the sharp edges of the barriers, and they are polluted first.

At the same time, the ventilation efficiency decreases, the concentration of oil vapours increases, and, accordingly, the amount of oil carried away through the oil collector increases. In addition, the pressure in the crankcase increases, which leads to the oil being squeezed out through the non-density. This is the next reason for a large oil consumption, but it is no longer associated with carbon monoxide. Most often, non-densities are formed in oil seals for reasons: their poor quality, wear (dirty oil), incorrect installation and overheating. There may also be oil leaks through the gaskets when they lose their properties and are not properly tightened, when the crankcase is hit, when the leakproofness of the sensor installation sites is violated, and other reasons. But all non-densities are mainly manifested when the pressure in the crankcase increases, except for the violation of the integrity of the cylinder head on the block.

Oil is released into the exhaust pipe through the turbine if the oil seal (oil seal) in the turbocharger fails. Then the oil that is fed to this turbocharger under pressure to lubricate the bearing will begin to flow into the exhaust pipe and, of course, burn there, or simply fly out of the pipe. The resource of this oil seal also depends on its original quality, operating modes (temperature) and oil quality. Oil release into the cooling system can occur if the part of the gasket that is located between the working cylinders and the cooling system holes is broken. The reasons for this may be poor-quality gasket, incorrect tightening or mismatch of the cylinder head and block planes.

WHAT SHOULD I DO IF I RUN OUT OF OIL?

For convenience, the cause, effect and diagnosis of large oil consumption are summarized in a table.

ReasonConsequenceDiagnosticsWhat to do
1. low-Quality oil

Increased oil fumes;

High carbon formation;

Significant contamination of the engine;

Increased wear of friction parts;

Reducing the compression and quality of fuel combustion;

Reduced oil life;

Loss of oil seal elasticity;

The failure of the engine.

Carbon on the cap of the neck;

Quick pollution of the oil;

The "drop test" method»;

A rapid method for determination of water content, viscosity, mechanical impurities;

Analysis in the laboratory of oils.

Replace with oil that corresponds to the engine and operating mode;

To protect the engine by Atomium technology.

2. Increased wear of the cylinder and piston group

"Pumping" of oil with oil-removing rings;

Increased oil fumes;

High carbon formation;

"Coking" of the rings.

A grey smoke on the move with an increase in the load or permanently (except for diesel engines);

The decrease in compression.

To restore technical condition by Atomium technology;

Replacement of the piston group.

3. Loss of mobility of oil rings

("lying down", " coking»)

"Pumping" of oil with oil-removing rings;

Increased oil fumes;

High carbon formation;

Over time, the power and pick-up rate decrease;

The increase in fuel consumption.

A grey smoke on the move with an increase in the load or permanently (except for diesel engines);

The decrease in power and throttle response;

The increase in fuel consumption.

If there is a large amount of carbon, it is possible to increase the compression above the nominal value.

Use flushing Atomium;

Processing engine technology Atomium;

Engine burn at high speed;

Engine overhaul.

4. non-Working oil caps

Increased oil fumes;

Possible burnout of the valves.

Blue smoke on" over-accelerating", then on the 5th -10th "over-accelerating " disappears completely (except for diesels);

The specific oil consumption on the highway is less than in the city.

To replace the valve seals;

Replace the guides and valves.

5. crankcase ventilation system is Faulty

Increased oil fumes;

High carbon formation;

Increased wear of friction parts;

Reducing the compression and quality of fuel combustion;

Degradation of the oil.

Carbon on the cap of the neck;

Quick pollution of the oil;

perform flushing of the crankcase ventilation system.
6.The leakage of oil through leakinesses

Increased oil consumption;

Oiling of the engine compartment and the environment.

test on paper-20 minutes – not a single drop;

Oil leaks (except for rear oil seal leaks).

If there is an increased gas pressure in the crankcase, find out the reason. Then point 2 or 5;

To eliminate leaks.

7. oil discharge into the exhaust pipe through the turbine

Increased oil consumption;

Failure of the turbine;

Failure of the catalyst.

Release of oil drops from the exhaust pipe on a cold engine (paper test on a pipe section);

Blue smoke from the chimney on the warmed engine;

Traces of oil on the joints (flanges) of the exhaust tract.

Replace the oil seal; repair or replace the turbocharger.
8. oil Release to the cooling system

Increased oil consumption;

Deterioration of the coolant quality;

Deterioration of heat exchange;

Coolant entering the lubrication system and loss of oil properties;

Waterhammer.

Oiling of the coolant (turbidity, color change);

Watering of the lubricating oil (foaming oil).

Engine overhaul.


HIGH OIL CONSUMPTION. HOW WILL ATOMIUM HELPS?

Very high oil consumption happens when the piston burns out or the crankcase is broken, but these incidents do not need comments. Repair of engines treated with SUPROTEC technology in such accidents will cost "a little blood", as the cylinders (shells) and the bearings will not be affected. In diesel engines, blue smoke from the pipe with the smell of oil and fuel occurs when the cylinder is not working. Then the oil consumption is also large. The reason is most often a faulty fuel injection equipment. Such failures are treated in the same way by ATOMIUM technology as in lubricating oil for restoring compression, and diesel fuel for restoring fuel pumps.