Attention! Work on replacing valve stem seals should be carried out when the corresponding cylinder is at BDC.
One of the reasons for the increased oil consumption is the wear of the oil scraper (oil deflectors) valve stem caps. Replacement can be carried out without removing the cylinder head from the engine using a special tool and a source of compressed air with a pressure of 6-8 bar (kgf/cm2).
Removal of valve stem seals must be carried out in the following order. Remove camshafts. Remove the cylindrical valve lifters. Set the piston of the corresponding cylinder to the TDC position by turning the crankshaft by the central bolt securing the belt pulley to the shaft until the camshaft cams take the position indicated in fig. 3.106.
In this case, the piston of the 1st cylinder will take the TDC position of the end of the compression stroke.
Put a chalk mark on the crankshaft pulley below and a second mark on the engine, strictly at an angle of 180°and move the cylinder piston to the BDC position, continuing to turn the crankshaft with a wrench (180°) until the chalk risks match. The piston of the 1st cylinder will take the BDC position.
Remove all spark plugs. Install the tool in the spark plug hole of the corresponding cylinder. Connect the tool with an air hose to a pressure source. Supply air to the cylinder at a pressure of 6-8 bar (kgf/cm). Install the tool and use it to remove the spring and valve plates.
Attention! Firmly seated valve cotters can be loosened by lightly tapping the fixture with a plastic mallet. Install the oil seal only if there is a plastic mandrel (cartridge cases).
Remove the tool, remove the valve stem seals using the tool «11.1.480» (see fig. 3.125).
Install the valve stem seal in reverse order, while lubricating the valve stem with engine oil.
Place a plastic mandrel on the valve stem «11.1.960» (pic. 3.126), which is included in the delivery of oil seals (1).
Lightly coat the inside of the oil seal with engine oil. Install the valve stem seal in the tool «11.1.200» (pic. 3.127).
Carefully and smoothly fit the valve stem seal onto the valve guide. Remove the plastic mandrel and the device for its installation. Assemble the valve by replacing the poppets, spring and valve cotters as described above. Replace valve stem seals on adjacent valves of the same cylinder.
Shut off the air supply to the cylinder and remove the tool «653/3» from the threaded hole of the spark plug.
Similarly, replace the valve stem seals on the valves of the remaining cylinders. Install cylindrical hydraulic tappets and valve camshaft. Reassemble the engine and check its operation at idle.