The oil seal must be replaced if oil is leaking from under the camshaft pulley
Oil splashing through the oil seal gets onto the timing belt and quickly corrodes it.
Before replacing the oil seal, you need to make sure that the engine crankcase ventilation system is not clogged.
Check if the ventilation hoses are pinched.
Because excess pressure in the engine crankcase will squeeze oil through all the oil seals and gaskets.
To replace the oil seal, prepare the car and the necessary tool.
Remove the upper and lower covers of the timing belt.
Turn the crankshaft and set the top dead center of the first cylinder according to the mark.
Using a 16 mm socket, loosen the camshaft toothed pulley mounting bolt, holding the shaft from turning with a screwdriver.
Insert the screwdriver through the pulley hole into the recess in the cylinder head.
Remove the timing belt (for more details, see the article - "Replacing the timing belt").
After removing the belt, do not turn the crankshaft and camshaft.
Unscrew the camshaft toothed pulley mounting bolt and remove the pulley.
Use a screwdriver to pry the oil seal out of the cylinder head seat.
Apply a thin layer of engine oil to the working part of the oil seal.
Carefully put the oil seal on the end of the camshaft
Using a suitable head or pipe, press in with light hammer blows
Install the camshaft pulley so that the protrusion on the pulley fits into the groove on the end of the camshaft
Further assembly is carried out in the reverse order
Tightening torque of the camshaft pulley mounting bolt - 67.42–83.3 Nm (6.88–8.5 kgf.m)