ATTENTION: Checking and adjusting the valves is performed both on a hot and on a cold engine. In the latter case, it is necessary to recheck the valve clearance on a hot engine.
Examination
Start and warm up the engine until the coolant temperature reaches 80-90°C, then turn off the engine.
Remove the upper intake manifold and remove the glow plugs.
Remove the cylinder head cover.
Set the gearbox to neutral and apply the handbrake.
Rotate the crankshaft clockwise by the central bolt until the groove on the pulley aligns with the "T" mark. Pistons of cylinders 1 and 4 are now at TDC. Cylinders are counted from left to right. Cylinder 1 is located on the V-belt side of the engine.
By moving the rocker arms of cylinders 1 and 4 up and down, check which of the cylinders is in the TDC position. If there is a gap in both the intake and exhaust valves, then this cylinder is in the TDC position of the compression stroke.
If the piston of the 1st cylinder is in the TDC position of the compression stroke, then the clearance of the valves indicated by white arrows is adjusted.
If the piston of the 4th cylinder is in the TDC position of the compression stroke, then the valve clearance indicated by black arrows is adjusted.
CAUTION: To change the position of the cylinders, turn the crankshaft one revolution clockwise.
Measure the valve clearance between the rocker arm and the valve surface using a feeler gauge.
If the feeler gauge is pulled through with tension, then the gap is adjusted correctly.
Required valve clearance values
| Required value on a hot engine | |
| Inlet valve | 0.25 mm |
| Exhaust valve | 0.25 mm |
| Required value with cold engine | |
| Inlet valve | 0.15 mm |
| Exhaust valve | 0.15 mm |
Loosen the lock nut approximately 1/2 turn while holding the adjusting screw with a screwdriver.
Turn the adjusting screw to set the valve clearance, constantly moving the feeler gauge.
Tighten the lock nut.
Recheck the valve clearance and repeat the adjustment if necessary.
Rotate the crankshaft one more revolution and check the clearance in the other valves.
Then check the insertion and tightening of the mounting screws and rocker arm mounting brackets.
Stop the cylinder head cover.
Screw in the glow plugs and install the upper part of the intake manifold.