We are replacing valve stem seals, guide bushings and valves on the VAZ 2107 - how to do it right
Excessive smoke from the exhaust pipe or an increase in engine oil consumption indicate wear on the valve stem seals, also called valve seals. It is not recommended to operate the car in this case in order to avoid serious damage to the engine. Even an inexperienced motorist can replace the valve seals with his own hands.
Oil scraper caps of the VAZ 2107 engine
Foreign matter must not enter the combustion chamber of a running engine, so cylinder protection is necessary. The role of the protective element is played by oil seals (seals). They prevent oil from entering when the valve stems move. If the caps do not cope with their functions, they will need to be replaced. Otherwise, carbon deposits may appear on individual engine elements and an increase in lubricant consumption.
Purpose and arrangement of caps
When the engine is running, the elements of the gas distribution mechanism (GRM) are in constant motion. To reduce their friction and wear, oil enters the timing from the sump under pressure, which should not enter the working area of the valves. Otherwise, the stable operation of the power unit will be impaired. Valve seals prevent oil from entering the combustion chamber.
More about the timing device: https://bumper.guru/klassicheskie-modeli-vaz/grm/grm-2107/metki-grm-vaz-2107-inzhektor.html
Oil scraper caps are arranged quite simply and consist of the following parts:
- Base. It is a sleeve made of steel, which is the frame of the cap and gives it strength.
- Spring. Provides a tight fit of the rubber to the valve stem.
- Cap. Removes excess grease from the stem. It is made of rubber and is the main structural element.
Previously, PTFE was used instead of rubber. Now manufacturers use materials that have increased wear resistance, long service life and are resistant to aggressive environments. If the caps fail, serious problems can arise. This is the reason for the high demands on the quality of the materials from which they are made.
Signs of wear
Timely detection of wear and replacement of VAZ 2107 caps will prevent serious engine malfunctions. The first signs of valve seal wear are as follows:
- Exhaust gases turn blue or white.
- Oil consumption increases.
- A layer of soot appears on the spark plugs.
If there are signs of wear on the valve stem seals, it will be necessary to check not only the caps themselves, but also the entire gas distribution mechanism, including the valves. Worn caps must be replaced. If this is not done in time, the following problems may appear:
- the engine will start to lose power;
- the engine will run unstable or stall at idle;
- the pressure in the cylinders will decrease;
- carbon deposits will appear on cylinders, pistons, valves, which will lead to loss of tightness.
The appearance of oil soot on the engine elements will reduce its resource and accelerate the need for major repairs. Timely replacement of caps will avoid these problems.
When to change valve stem seals
When the sealing material of the glands hardens, that is, becomes less elastic, oil will begin to seep into the cylinder. However, it can begin to flow there even when the piston rings are worn. You should be puzzled by the urgent replacement of the caps when the oil level drops without visible leaks. In the process of movement, it is necessary to observe the exhaust. You must first slow down the engine, and then sharply press the gas pedal. If thick bluish smoke comes out of the muffler, then the valve stem seals are worn out. A similar effect will be observed after a long parking of the car.
This is explained quite simply. If there is a leak between the valve stem and the guide sleeve, oil will begin to flow into the engine cylinder from the cylinder head. If the piston rings are worn or coked, the behavior of the engine will be somewhat different. In this case, a characteristic smoke trail will remain behind the machine only when the engine is running under load (when driving dynamically, driving downhill, etc.). Indirectly, worn rings can be judged by increased fuel consumption, reduced engine power and problems with starting it.
Choice of new caps
When buying new valve stem seals, the owners of the VAZ 2107 have a choice problem. There is a wide range of such products on the market - from really high-quality products to outright fakes. Therefore, the acquisition of new caps should be attributed extremely responsibly, primarily paying attention to the manufacturer. When buying, preference should be given to products from Elring, Victor Reinz, Corteco and SM.
Replacement of valve stem seals VAZ 2107
The following tools are required to replace the valve stem seals:
- cracker (valve puller);
- torque wrench;
- tin bar;
- screwdriver;
- new oil seals.
The replacement itself is carried out in the following order:
- We drain part of the coolant (about two liters).
- We remove the air filter together with the body and the carburetor throttle rod.To remove the valve cover, you will need to remove the air filter and housing.
- We dismantle the valve cover.To dismantle the valve cover, you need to use a 10-nut wrench to unscrew the fastening nuts
- We set the first cylinder to top dead center (TDC).The first cylinder must be set to top dead center
- Slightly loosen the chain tension nut and unscrew the bolt securing the camshaft sprocket.To remove the camshaft gear, loosen the chain tension
- We remove the gear together with the chain and tie them with wire so that they do not fall into the crankcase.
- Having unscrewed the fasteners, remove the bearing housing and rockers with springs.The fastening nuts are unscrewed and the bearing housing is dismantled, as well as rockers with springs
- We unscrew the candles. To prevent the valve from falling into the cylinder, we insert a tin rod into the candle hole.To prevent the valve from falling into the cylinder, a soft metal bar is inserted into the candle hole.
- Opposite the valve from which the "crackers" will be removed, we install a cracker and fix it on a hairpin.
- We compress the spring with a cracker until the crackers can be freely removed from the valve stem.The cracker is fixed on a pin opposite the valve from which it is planned to remove the crackers. The spring is compressed until the crackers are released
- After dismantling the spring and support washer with tweezers or a screwdriver, remove the oil scraper cap.The oil scraper cap is removed from the valve stem with a screwdriver
- Before installing a new cap, lubricate its working edge and valve stem with engine oil.Before installing a new cap, its working edge and valve stem are lubricated with engine oil.
- We put the springs in place, then the support washers and the spring plate.Springs, support washers and spring plate after replacing the cap are installed in place
- We repeat all these steps with the rest of the cylinders, not forgetting to turn the crankshaft so that the corresponding pistons are at TDC.
After replacing the caps, the crankshaft returns to its original position, the bearing housing, the camshaft sprocket are installed, and then the chain is tensioned. The assembly of the remaining nodes is carried out in the reverse order.
Video: replacing valve stem seals VAZ 2107
Replacing engine valves VAZ 2107
The need to replace the VAZ 2107 valves arises in the following cases:
- the valves are bent due to a jumped timing chain or as a result of severe stem wear;
- cracked plate;
- the valve burned out.
Learn how to replace the timing chain: https://bumper.guru/klassicheskie-modeli-vaz/grm/grm-2107/zamena-cepi-grm-vaz-2107-svoimi-rukami.html
For repairs, you will need to purchase new valves and prepare the tools used to replace the valve stem seals. In addition, the cylinder head must be removed from the engine. This is done in the following way:
- With a head of 10, we turn off the cylinder head fasteners.To remove the cylinder head, you need to unscrew the mounting bolts with a 10 head
- We dismantle the cylinder head.After unscrewing the fasteners, the cylinder head can be easily removed
- Remove the valves from the inside of the cylinder head.After cracking, the valves are removed from the inside of the cylinder head
- We install new valves, not forgetting about grinding.
- The assembly is carried out in the reverse order.
Replacing the valve guides
Valve bushings (valve guides) are designed to guide the movement of the valve stem. Due to the exact fit of the head on the seat, the combustion chamber is sealed. The correct operation of the valves largely depends on the serviceability of the seats and guides, which wear out over time and begin to negatively affect the operation of the engine. In this case, bushings and saddles must be replaced.
With severe wear of the bushings, oil consumption increases, oil scraper caps fail, and lubricant enters the cylinders. As a result, the temperature regime of the engine is disturbed, and carbon deposits form on its individual parts. The main signs of guide wear:
- increased oil consumption;
- the appearance of noise in the cylinder head area.
To make sure that it is the bushings that are faulty, you need to open the hood and listen to the operation of the motor. If uncharacteristic sounds and noises are heard, then it will be necessary to diagnose the valves and their guides.
For repair you will need:
- a hammer;
- sweeps for 8.022 and 8.028;
- mandrel for pressing out and pressing in bushings.
Valve bushings are replaced on the removed engine head in the following sequence:
- We strike the mandrel with a hammer and knock out the valve guide.The VAZ 2106 guide bushing is pressed out of the socket using a special tool
- We insert a new bushing into the saddle and press it into the plane of the head with a hammer and mandrel.The new bushing is inserted into the seat and pressed in with a hammer and mandrel.
- After mounting with a reamer, we adjust the holes of the bushings to the desired diameter.Having installed the guides in the head, it is necessary to fit them using a reamer
Replacing the valve seat
The operation of valves with seats, as well as the entire engine, is associated with exposure to high temperatures. This can lead to the formation of various defects on the parts, such as shells, cracks, burns. If the cylinder head overheats, misalignment between the valve sleeve and the seat may occur. As a result, the tightness of the connection will be broken. In addition, the seat wears faster along the cam axis than in other places.
To replace the seat, you will need to remove it from the seat. The required set of tools and equipment may vary depending on the capabilities of the car owner:
- machine;
- electric drill;
- a hammer;
- metal tip;
- old valve.
The seat can be removed in the following ways:
- With the help of a machine. The saddle is bored and becomes thin and less durable. In the process, the rest of the saddle is rotated and removed with pliers.
- With an electric drill. A small abrasive wheel is clamped into the drill chuck, the tool is turned on and cut into the saddle. At a certain point, the part can be removed due to loosening of the tightness.
- By welding. The old valve is welded to the seat in several places. The valve together with the seat is knocked out by hammer blows.
Read about the overhaul of the VAZ 2107: https://bumper.guru/klassicheskie-modeli-vaz/poleznoe/remont-vaz-2107.html
The installation of a new seat is carried out in the following order:
- To ensure the necessary tightness of 0,1–0,15 mm, the cylinder head is heated on a gas stove to 100 ° C and the seats are cooled in the freezer of the refrigerator for two days.
- The seat is pressed into the engine head with gentle hammer blows through the adapter.
- After the heads have cooled, they begin to countersink the saddles.
It is best to cut the bevel on the machine. Rigid clamping of the part and centering of the cutter will provide high precision, which cannot be obtained using hand tools. If this is not possible, you can use cutters and a drill.
Three edges are cut on the saddle with cutters with different angles:
- external (60˚);
- internal (30˚);
- central (45˚).
The last edge is the narrowest. It is with her that the valve will come into contact. After that, it remains only to grind the valves.
Video: valve seat replacement
Lapping valves VAZ 2107
Lapping of valves is necessary to ensure the tightness of the combustion chamber. It is performed not only after replacing the seat, but also with a decrease in compression in the cylinders. You can perform lapping in the following ways:
- on a special machine;
- manual cutter;
- mechanically.
Since special equipment can only be found in car services or machine shops, in garage conditions the latter option is the most common. For manual grinding you will need:
- diamond paste;
- soft spring;
- kerosene;
- drill.
Lap the valves in the following sequence:
- We put a spring on the valve and insert its stem into the sleeve.The valve with a spring put on it is inserted into the sleeve
- We press the valve with a finger to the seat and clamp the stem into the drill chuck.
- We apply abrasive material to the surface of the plate.An abrasive paste is applied to the plate to grind the valves.
- We rotate the valve with a drill or screwdriver at a speed of about 500 rpm in both directions.The valve with the stem clamped into the drill chuck is lapped at low speed
- The procedure is performed until a characteristic matte ring appears on the saddle and plate.A characteristic matte ring appears on the lapped valve
- After lapping, wipe all valves with kerosene and wipe with a clean rag.
Video: lapping valves VAZ 2101-07
Watch this video on YouTube
Valve cover VAZ 2107
Sometimes the VAZ 2107 engine is covered with oil on the outside. The reason for this is usually a worn valve cover gasket, through which lubricant leaks. The gasket in this case is replaced with a new one.
Replacing the gasket
The valve cover gasket can be made of rubber, cork, or silicone. Each option has its own advantages and disadvantages. Therefore, the final choice of gasket material depends only on the personal preferences of the car owner.
To replace the gasket you will need:
- end head 10;
- small extension cord;
- vorotok or rattle;
- dry rag;
- new gasket.
The gasket is replaced in the following order:
- We dismantle the air filter together with the housing.
- Disconnect the throttle control rod on the carburetor.When replacing the valve cover gasket, disconnect the carburetor throttle control rod
- We unscrew the fasteners of the valve cover and remove all the washers.Nuts of fastening of a cover of valves are turned away by an end head on 10
- Remove the valve cover.The valve cover is removed from the studs
- We remove the old gasket and clean the surface of the cover and cylinder head from contamination.After removing the old gasket, you need to clean the surface of the cover and cylinder head from dirt
- We put on a new seal.
The cover is installed in the reverse order, and the nuts should be tightened in a strictly defined order.
Thus, it is quite simple to replace the valve seals and the VAZ 2107 valves themselves. Having prepared the appropriate set of tools and carefully studied the recommendations of professionals, even a novice motorist can do this.