Increased oil consumption is the result of two types of malfunctions:
1) a breach of the tightness of the connections of engine parts and units, due to which oil leaks out. The defect, as a rule, occurs due to loosening of the tightening of the mating parts (cylinder head cover, cylinder head, fuel pump - cylinder block, cylinder block - sump, etc.) or deformation of the sealing gaskets;
2) failure of the crank mechanism parts; wear of piston rings, pistons or cylinders; piston ring seating in piston grooves; piston ring failures; damage to valve stem seals; increased wear of the valve stem or guide bushings. The listed defects occur due to prolonged engine operation with overheating. Oil easily gets into the combustion chamber and is thrown out of the muffler already half-burned. In order to correctly assess the malfunction based on the emissions from the muffler, we remind you that blue smoke from the exhaust occurs when oil gets into the combustion chamber, black smoke - with a rich mixture, white - when coolant gets into the combustion chamber. Spark plugs are not ignored either; they increasingly have to be removed and burned.
There is no need to worry when filmy oil stains appear in certain places of the engine. This is not a crime. Another matter is when the oil clearly tends to penetrate through the leaks in the connections and, mixing with dust, contaminate the engine surface. The places where oil can penetrate are well studied.
If dirt periodically forms along the contour of the contact between the timing cover and the cylinder head, the culprit is either the gasket, or insufficient uneven tightening, or the gasket protruding from under the flange of the cover.
The front of the engine is difficult to access, and oily dirt tends to accumulate there. The reason is the loosening of the camshaft drive cover. The heads of the bolts securing the cover are suitable for a 10 mm spanner, and if you artificially lengthen the key rod, tightening the cover fastening will not be difficult.
If you open the hood and find oil stains around the oil filler neck more and more often, you should thoroughly wash the filler cap in gasoline. The culprits of oil penetration and contamination of the front and rear parts of the engine in the crankshaft area are usually the seals. Here you need to realistically assess the situation. If only a small surface is oiled directly at the crankshaft pulley and the crankcase cover, then there is no reason to replace the seals.
Dealing with all types of oil leaks is unpleasant, but not so difficult, if only because it is clear where it is leaking from. It is more difficult when the cause is unclear. If you suspect that the crank mechanism parts are faulty, you need to contact specialists.
So, when the muffler emits blue smoke, the reason is clear. The engine needs to be disassembled and, most likely, a number of parts need to be replaced. But it happens that everything is fine with the exhaust gases, there are no traces of oil leaks, but the oil still disappears. The reason will become clear if one or more engine cylinders periodically refuse to work. Remove the spark plug or spark plugs from these cylinders and you will see that they are splashed with oil. The rubber oil deflector cap 10 (see fig. 47), and the oil was able to enter the combustion chamber.
The cap costs pennies, and the work to replace it is more than 25 rubles. Naturally, experienced car enthusiasts solve this problem themselves, although to solve the problem, preparatory work is necessary to dismantle the parts that interfere with access to the caps, and to make the appropriate equipment and, above all, the device shown in Fig. 49.
The operation must be performed with an assistant in the following order:
- using a starting handle or a special key to turn the crankshaft of a car engine VAZ-2105 and VAZ-2107 turn the crankshaft to such an angle that the piston in the cylinder being examined reaches the top dead center;
- given that the chain or belt is free from tension, it is necessary to artificially roll the gear along the chain. This work should be performed by an assistant;
- using a device (see fig. 49) remove the valve springs. To hold the valve in place, an assistant should hold the valve with a long screwdriver or a metal rod with a diameter of 9-10 mm and a length of 300 mm, acting through the spark plug hole. To prevent all sorts of accidents, the device (its working organ) and it is advisable to cover the spring being removed with a rag when dismantling the valve;
- using two screwdrivers to pry the lower edge of the cap, remove it. When doing this, you need to be careful, since one unsuccessful movement of the screwdriver and the thin-walled part of the valve guide bushing is deformed and it is necessary to remove the cylinder head to replace the bushing;
- press on a new cap using a mandrel and a tube of the appropriate diameter. The main thing is that the cap sits in its place without skewing, since a new one, but installed skewing, will not be able to keep the oil from penetrating the spark plug.
After completing the work on replacing the cap, it is necessary to install all previously dismantled parts, and then carry out adjustment operations similar to those performed after replacing the engine camshaft.