Checking the tightness of the cylinder head bolts
Check the tightness of the cylinder head bolts at the end of the run-in and every 40 thousand km on a warm diesel engine in the following order:
- - remove the cap and cylinder head cover;
- - remove the rocker arm axle with rocker arms and struts;
- - using a torque wrench, check the tightness of all cylinder head bolts in the sequence shown in Figure 1, and, if necessary, tighten them.
Tightening torque -220±10 Nm.
After checking the tightness of the cylinder head bolts, reinstall the rocker arm axle and adjust the clearance between the valves and rocker arms.
Checking the gap between valves and rocker arms
Check the gaps between the valves and rocker arms and, if necessary, adjust every 20 thousand km, as well as after removing the cylinder head, tightening the cylinder head bolts, and when valve knocking occurs.
The gap between the rocker arm striker and the end of the valve stem when checking on an unheated diesel engine (water and oil temperature no more than 60°C) should be:
- 1) intake valves - 0.25 mm;
- 2) exhaust valves - 0.45 mm.
When adjusting the gap between the end of the valve stem and the rocker arm on a cold diesel engine, set:
- intake valves - 0.25 mm;
- exhaust valves - 0.45 mm.
Adjustment is carried out in the following sequence:
- - remove the cylinder head cover cap and check the fastening of the rocker arm axle struts;
- - turn the crankshaft until the valves in the first cylinder overlap (the intake valve of the first cylinder begins to open, and the exhaust valve finishes closing) and adjust the clearances in the fourth, sixth, seventh and eighth valves (counting from the fan), then turn the crankshaft to one turn, setting the overlap in the fourth cylinder, and adjust the clearances in the first, second, third and fifth valves.
To adjust the gap, loosen the lock nut of the screw on the rocker arm of the adjustable valve in accordance with Figure 2 and, turning the screw, set the required gap using the feeler gauge between the rocker arm striker and the end of the valve stem.
After setting the gap, tighten the lock nut.
After adjusting the valve clearance, replace the cylinder head cover cap.
