Replacing the seals of both cylinder head covers, the engine must be carried out in the following order.
Disconnect «negative» terminal from AB and remove the soundproof casing (see fig. 4.26) and a partition.
Remove the bellows from the throttle shaft and the upper part of the air filter housing together with the air flow meter. Remove the lower part of the air filter housing and unscrew «+» AB wire on the front panel of the engine compartment. Insulate the wire with a cap with insulating tape. take out «+» AB wire and put it aside.
Remove the washer fluid reservoir from the side of the cylinder head cover 1 to 4. Release the cooling system hoses from the clamps and from the bracket on the valve and take them to the side, from the side of the head cover of the block 5 - 8 cylinders. Do not disconnect hoses.
A ventilation duct is laid under the casing of the ignition coils (1, fig. 4.37) front axle gearbox and «+» the wire (2) AB.
Open the plugs of the casing of the ignition coils and remove the ignition coils.
On the bank of cylinders 5 - 8, disconnect the hose (1, fig. 4.38) crankcase ventilation from the cylinder head cover.
Unscrew the fastening bolts and move the right and left cable boxes to the center of the engine.
Unscrew the left and right fasteners (11 pcs.) cylinder head cover and remove the cover.
Install the covers in reverse order, checking the condition of the gaskets and, if necessary, replacing them.
Clean the sealing surfaces of the cylinder head and head cover from the remnants of the old seal. Use a hardwood scraper for cleaning (beech, hornbeam, oak).
Coat the entire perimeter of the outer and inner grooves, as well as on the sealing surface of the cylinder head cover, with a lubricant to improve rubber slip, such as glycerin or petroleum jelly (pic. 4.39).
Loosely fit the inner gasket into the groove, starting at the rounded corners. Loosely install and align the outer gasket with the groove in the cover into the groove, starting from the rounded corners.
At the joints between the cylinder head and the timing cover on the left and right sides (arrows, fig. 4.40 a)
and at the rounding points between the cylinder head and the VANOS adjustment units on the left and right sides (arrows, fig. 4.40, b) apply sealant bead type Drei Bond 1209. Check that the gasket is correctly installed around the edges and at the rear of the cylinder head.
Prepare the cylinder head cover bolts. The sequence of installation of bolt elements is shown in Figure 4.41.
Insert cover bolts at fixed points (arrows, fig. 4.42) and align the cylinder head cover.
Screw in all bolts (M6) fastening the cover by hand, without tightening them completely.
Tighten the cover bolts in a criss-cross pattern from the middle to the edges. Do not overtighten bolts.