CAUTION: This operation applies to engines that do not have hydraulic valve lifters.
Start the engine and warm it up to a coolant temperature of 80-95°C.
Remove all spark plugs.
Remove the cylinder head cover.
Turn the crankshaft clockwise until the mark on the pulley aligns with the "T" mark on the scale on the lower camshaft drive belt cover.
Rock the rocker arms of the valves of the 1st and 4th cylinders to determine in which cylinder the piston is at TDC of the compression stroke; if there is a gap between the rocker arms of the valves of one of the cylinders, the piston of this cylinder is at TDC of the compression stroke.
If the piston of the 1st cylinder is at TDC of the compression stroke, check and adjust the clearances in the valve drive, shown in the figure by the white arrow; if the piston of the 4th cylinder is at TDC of the compression stroke, the adjustment is made on the rocker arms, shown in the figure by the black arrow.
Measure the clearance in the valve drive. If the clearance does not correspond to the required values, loosen the lock nut of the rocker arm adjusting bolt and adjust the clearance by measuring it with a measuring gauge and turning the adjusting bolt.
Required clearance value (hot engine): intake valve 0.20 mm, exhaust valve 0.30 mm.
Rotate the crankshaft 360° until the mark on the pulley matches the "T" mark on the scale of the lower camshaft drive belt cover. Adjust the clearances in the drive of the remaining valves as described earlier.