Sometimes situations arise when operating a car, when the engine begins to lose power, and fuel consumption increases significantly. One of the reasons may be valve burnout as a result of the use of low-quality fuel. Replacing them on a classic VAZ car is not particularly difficult. To do this, you only need to follow the order during disassembly and assembly.
Necessary
- - puller for drying valves;
- - socket heads for 10, 13, 22;
- - lapping grease.
Instructions
Step 1
Remove the cylinder head from the car engine in order to check or replace the valves. To do this, it is not necessary to remove the engine itself. Drain the cooling system, remove the air filter. Disconnect the wires from the battery, spark plugs and temperature sensor. Disconnect the carburetor choke actuator. Use a spark plug wrench to unscrew the sensor and candles. Disconnect the throttle rods with a screwdriver. Remove the valve cover with a 10-point socket.
Step 2
Align the mark on the crankshaft with the middle mark on the front cover of the engine, and the mark on the camshaft sprocket with the filler on the housing of its bearings. Using a screwdriver or a 6 key, remove the hose clamps for the interior heater. Disconnect the hoses of the cooling jacket, carburetor. Remove the starter protective casing with socket head 13 and disconnect the muffler pipe ("pants") from the manifold.
Step 3
Loosen the chain tensioner nut, depress its stem and fix it. Remove the sprocket and bearing housing with it from the camshaft. Remove the cylinder head bolts. Place the cylinder head on a flat surface and disconnect the exhaust manifold, then remove the carburetor with intake manifold. Remove the cooling jacket outlet. Remove the levers ("rocker arms") of the valves, freeing them from the springs. Unscrew the adjusting bolts and their bushings by loosening the locknuts.
Step 4
Take the spring remover and remove the valve nuts. Also remove the valve springs with poppets and washers. Turn the cylinder head and pull out the valves. Remove the valve stem seals from the guide bushings.
Step 5
Inspect valve seats. They should be free of corrosion, pits and other damage. If found, grind the seats. At the same time, try to remove as little metal as possible. This can be done either manually or with a special machine. To do this, place the head on a flat surface. Take a countersink and clean the carbon chamfers from the saddles. Note that the diameter of the inlet seat is smaller than the outlet. Take a new valve and check the gap between its rod and the guide sleeve by measuring it and its diameter: for exhaust valves it is 0.029-0.062 mm, for intake valves 0.022-0.055 mm. If you cannot eliminate it, replace the bushings.
Step 6
Install the valves and grind them to the seats with "Diamond Lubricant". To do this, take the valve stem, press it against the seat, after having lubricated it, and rotate it quickly left and right. After the chamfer is completely across the width of the valve chamfer, reassemble the valve train in reverse order. Adjust the valves and install the cylinder head on the engine, while always replacing the gasket between the head and the cylinder block.
