Replacing the left upper timing cover
Removing the left upper timing cover (pic. 4.64) engine must be carried out in the following order.
Remove left cylinder head cover, blower coupling with impeller and VANOS adjustment solenoid valve.
Disconnect plug connector (ShS) from the air shut-off valve, to purge the engine crankcase, from the left and right upper timing covers of the engine. Loosen the bolt (arrow, fig. 4.65), disconnect the air supply pipe from the bracket and remove it.
Remove bolts (6, 7, see fig. 4.64) fastening the upper timing cover and remove it. Remove profiled rubber seal (5).
The installation of the upper, left timing cover of the engine should be carried out in the reverse order, while it is necessary to clean the groove for the profiled rubber gasket and the sealing surfaces from the remnants of the old seal. Sealing surfaces must be free of dirt and oil.
Apply to the mating surfaces of the parting plane between the cylinder head and the timing cover (arrows, fig. 4.66) type sealant layer «Drei Bond 1209».
Insert a new profiled rubber seal into the groove, paying special attention to correct seating. install bolt (1, see fig. 4.67) in the timing cover, because later it will not be possible to insert it, and install the timing cover on the engine cylinder head.
Install the fastening bolts in the timing case cover and screw them in by hand until they are in contact with the engine cylinder head. Remove the outer and inner gaskets from the cylinder head cover.
Insert fixture «11.6.432» (pic. 4.68) from the kit «11.6.430», into the groove on the cylinder head cover and install the cover.
Fit nuts (1, fig. 4.69) and tighten them in several steps of half a turn, with a final tightening torque for M7 nuts - 15 Nm (1.5 kgf·m), for M6 nuts - 10 Nm (1.0 kgf·m).
In this case, the timing cover is pressed by the head cover to the surface of the cylinder head.
Tighten the bolts (6, 7 see fig. 4.64) on the timing cover in two steps, crosswise, with the final tightening torque for the M8 bolts - 22 Nm (2.2 kgf·m), for M7 bolts - 15 Nm (1.5 kgf·m), for M6 bolts - 10 Nm (1.0 kgf·m).
Remove cylinder head cover and remove tool «11.6.432» (see fig. 4.68). Install solenoid valve for VANOS adjustment unit. Clean the sealing surfaces of the cylinder head, replace the secondary air pipe o-rings, and coat it with a thin layer of grease to make it easier to slide. Continue assembling the engine.
Replacing the right upper timing cover
The removal of the right upper timing cover of the engine should be carried out in the same technological order, taking into account the following points.
After removing the right cylinder head cover, remove the chain tensioner plunger. Remove bolts (arrows, fig. 4.70) fixing the sealing flange, which is installed on top of the solenoid valve (EMC) and seals the timing cover.
Clean the EMC from contamination and remove the sealing flange.
If necessary, remove the camshaft position sensor or disconnect the loop on the cable box.
When installing the upper, right timing cover, replace the sealing ring in the oil supply channel (1, fig. 4.71) to the chain tensioner in the cylinder head.
Before installing the timing cover, press the tensioner bar to the center and only then install the timing cover on the engine cylinder head.
When installing the right timing cover, use instead of tool «11.6.432», fixture «11.6.431» from the kit «11.6.430». Clean the EMC and the sealing surface.
Check and, if necessary, replace the sealing flange (1, fig. 4.72).
Lightly lubricate with oil the inner surface of the flange to be sealed, adjacent to the EMC, and carefully fit the flange. Insert and tighten the mounting bolts.
Continue assembling the engine.
Replacing the lower timing cover
The design of the lower timing cover is shown in Figure 4.73.
Replacing the lower timing cover must be carried out in the following order. Disconnect «–» terminal from AB, drain the coolant and send it for recycling.
Remove the right and left upper timing case covers. Pull out the vibration damper hub and remove the coolant pump together with the thermostat housing.
Attention! When a liquid-cooled generator is removed from the engine, coolant residue flows out of the timing cover, which must be collected and sent for disposal.
Remove the liquid-cooled alternator, top of the oil sump, press the tensioner bar against the drive chain and fix it in this position with a bracket (1, fig. 4.74).
Remove bolts (arrows) fastening the lower timing cover to the cylinder block and remove it.
Clean the sealing surfaces on the lower timing case cover and cylinder block using a hardwood scraper (beech, hornbeam or oak) and check the centering sleeves for damage and correct installation.
Attach new gaskets (6, see fig. 4.73) on the cylinder block with a small amount of sealant type «Drei Bond 1209», applied on the front and back surfaces of the gaskets in a thin layer.
Install the timing cover and screw in all the bolts (15 pcs.) its attachment to the cylinder block. Bolts pre-tighten to 5 Nm (0.5 kgf·m). Tighten all bolts (M7) fastening the timing cover to the cylinder block in a checkerboard pattern with a torque of 15 Nm (1.5 kgf·m).
Attention! When all the bolts are tightened, for control, go through them again in a checkerboard pattern with a tightening torque of 15 Nm (1.5 kgf·m).
Replace the crankshaft front oil seal, screw plug O-ring (M14x1.5) drain hole of the cooling system and tighten it with a torque of 25 Nm (2.5 kgf·m). Assemble the engine.
Fill with coolant. Remove air from the cooling system and check it for leaks.