Engine oil is a very serious component of any engine, without which it will not work even a day. Lubricants are constantly being improved, for the better. At this point, they differ in the types of minerals, semi-synthetic and synthetic, part of which is written about in this article.
You can check the level using an oil dipstick, if the level is normal, then there is nothing to worry about, just change it after the required number of kilometers. But what if the levels keep dropping? Should the consumption of your car increase or, as they say in the garage, “the engine is consuming oil”?
There are many reasons here, in this material I will try to list all of them, some are easy and completely trivial, but some are complex, when identified, often need to make major repairs. Well, let’s keep reading this article until the end.
If the consumption of oil in the engine increases, and the level continues to fall (that is, you are replenishing several hundred grams of oil every week), then this is very bad. This means your power unit has a problem which will need to be removed immediately, otherwise you can easily hear a “knock” sound.
No, of course, the engine has an allowable lubricant consumption, usually 0.05 – 0.25% of the fuel you use. This means that if the gasoline is filled with 100 liters, the oil consumption will be around 5 grams. This is a valid value.
Excess oil consumption may not occur, if the engine is new, usually excess consumption will occur if the engine is worn. However, if the oil consumed is more than five grams, it definitely needs attention. Easy to check the level on the measuring stick.
I divided the damage into complex (which is difficult to remove and requires a complex machine disassembly) and light (disassembly of the entire unit is not required). So, in our article I will begin, perhaps, with complex breakdowns.
Damage Complex With High Engine Oil Consumption
- Wear (excess heat) of the piston rings. There are oil scraper rings on any engine pistons, they are the ones that prevent oil from entering the combustion chamber. This ring always rubs against the cylinder block wall. When they grind, oil begins to enter the combustion chamber slightly, burns there, and exits with exhaust gas.
- In addition, this ring can overheat, for example, if there is no coolant (or insufficient level), the engine warms up to a critical point and this ring “lies down”, that is, it loses its elasticity and compresses the piston.
- Perhaps many have seen cars that have blue exhaust (rare, but can be found on the road), this indicates damage to the oil scraper ring. So, the oil burns out and the level drops (“FAT” appears). You need to disassemble the engine and replace the oil scraper ring. Repairs are also quite expensive.
- Cylinder block wall wear. Another reason is the wear and tear of the cylinder block walls, where the piston moves. That is, not the ring itself, but the wall on which the piston is located with the oil scraper ring applied to it. There’s nothing you can do, either, hold back or change it. Repair costs are also very expensive.
- Through the valve stem seal. Those valve oil seals, they remove oil from the valve gears themselves. With wear or temperature fluctuation, this cap becomes inelastic, and does not remove grease from the valve, this is another direct cause of consumption. Everything is a little simpler here, because this flap is located at the top, head of the block. And to replace it, you don’t need to take the entire power unit apart. Often times, you just need to remove the head cover block.
- Leaking through cylinder block gasket. By the way, it should be noted that the V8 unit has two of them. This can happen only for two reasons, or a manufacturing defect, simply not tightening the fastening bolts. And second, your engine is so worn out that even the gasket catches fire. Here it is also more or less cheaper, the gasket is at the back of the head, so there is no need to remove the engine. Easy to diagnose, there are two options. It flows along the beam walls – from the outside to be precise from the point of installation. Either there was no external leak, but a lump of oil was observed in the cooler, and the level dropped. Just remove the block head, replace the gasket and then tighten it well.
- Leaking through the crankshaft and camshaft oil seal. Another “complex” reason for excess oil consumption is a leak in the crankshaft and camshaft oil seal. The front of the engine has a cover through which the initial crankshaft exits. It has an oil seal that can leak. Either because of wear (poor quality), or because of low temperature or because of bad engine oil (wrong choice), engine oil will just come out. The rear crankshaft oil seal is even more difficult to diagnose, the problem of the rear often gets into the gearbox, it is impossible to see it, you need to remove the “box”, but again, if a puddle is under this place and the level is constantly dropping, it is likely big you have to start unpacking it.
- The same story goes for the camshaft, (although it does not have a rear oil seal, only front seal), it is not always possible to see stains, because it is covered with a timing belt cover (usually plastic), The stain on the crankcase guard will blow your mind, and often the belt can come loose, which will cause the valve to bend! So there’s no point in delaying replacement. Here the solution is to replace the oil seal as needed.
- Leaking oil filter. The most common type of “minor” damage is an oil filter leak. An oil puddle will form under the vehicle. There are several reasons for this, they are simply not tightening the oil filter, tearing up the casing (sometimes from low-quality manufacturers), or the gasket adjacent to the block is absent. After all, you’re better off buying a new one.
- Through the cylinder block cover. The cylinder block has a cover fastened with 6 to 12 bolts, it also has a gasket which can also leak which increases the oil consumption. This is because the gasket is of poor quality so it doesn’t last long. Try holding the lid, if it doesn’t help you need to replace it again.
- Machine pot. It also has a gasket, only at the bottom. It’s easier to see, just get the car in the elevator, or just enter the pits. He also voices from time to time, or from poor quality performance. We just changed.
Separately about oil and its waste
- First, I want to tell you that burning engine oil is a completely normal process in the operation of any internal combustion engine, not a single unit does not burn.
- The problem is that oil envelops the cylinder walls (lubricates it and increases its resource), of course it is removed by the oil scraper ring, but a part (very small in a working engine) remains in the combustion chamber, when the combustible mixture ignites, it burns and excreted together with exhaust gas through the exhaust system.
- BUT, as I wrote above, there is a special average rate for this, which is confirmed by the manufacturer – usually 50 – 100 grams per 10,000 km, up to a maximum of 300 – 400 grams. But it happens when the oil burns more than necessary! So why is this happening, there is a logical reason for this.
- Bad or unsuitable oil. If everything is more or less clear with bad or fake lubrication, you just “mess” with a fake and it is better to replace it, if it burns in liters, turns black after 500 km, without damage. The wrong parameter is a little more complicated.
- I want to say that each manufacturer determines what kind of oil can be poured on this particular device. If you fill in too much liquid oil, it will stick to the walls and burn in the room. If the filling is too thick, then the film that will form on the walls will become too thick, by the way, it can cause increased wear of the rings.
- Remember – make sure to choose a lubricating fluid exactly according to your manufacturer’s recommendations, they give it for a reason, everything is calculated at the production level.
- Severe mode of operation. Usually, this is called high-speed operation of the power unit! For example, suppose you like to crank your engine to the limit, and the higher the rpm, the higher the oil consumption. Simple physics works here, the revolution is high, the temperature rises more than necessary, the lubricant becomes thinner and more remains in the combustion chamber.
- Also, temperature conditions play a role, in winter, oil is consumed more in the engine than in summer. It becomes thick and cannot form a normal film for the first few seconds of work. That is why if you warm up the engine in a frozen state, it is difficult to start at no load for a few minutes, because there is increased wear on the rings and walls of the cylinder block. I recommend changing the oil before winter, because it loses its properties with high mileage.
Separately about the turbo engine
It’s no secret that turbocharged engines consume more oil than conventional engines (by the way, which one is better – talking here). The problem is that old turbines are properly cooled from the engine’s lubrication system, and if the turbine breaks down, it can move oil through its bearings, and the consumption can be quite large, around 1 – 3 liters per 10,000 kilometers, and in some cases damage can occur.
In addition, in the event of a turbine failure, an increase in crankcase gas pressure may occur. This allows oil to enter the cylinder directly through fuel injection from the crankcase ventilation system. The turbine definitely needs to be replaced or repaired.
I wrote a lot, and as you can see, the reasons are not always clear, you need to consider each case.