Replacing the left cylinder head
The left cylinder head includes cylinders 5–8. Removal of the left cylinder head must be carried out in the following order.
Remove left exhaust manifold, drain and dispose of coolant.
Remove the covers of both cylinder heads, unscrew the spark plugs. Remove intake manifold (see fig. 4.108)
and coolant manifold (see fig. 4.107).
Remove VANOS adjustment unit from left cylinder head. Remove retainer «11.5.180» enough to free the crankshaft flywheel (pic. 4.43).
Pull back the camshaft timing chain and keep it taut.
Turn the crankshaft at the central bolt against the direction of rotation to a position of 45°before top dead center (TDC) end of compression stroke (pic. 4.44)
and remove fixtures «11.2.444/443/ 442/446» (pic. 4.45).
Loosen the bolt (arrow, fig. 4.46) cylinder heads.
Loosen and unscrew the cylinder head bolts in the sequence 10 - 1 (pic. 4.47).
Remove the cylinder head and gasket; the gasket is no longer usable.
Installation of the cylinder head must be carried out in the reverse order, while it is necessary to clean the sealed (docking) surfaces on the timing cover, engine head and cylinder block using only a hardwood scraper for this purpose (oak, hornbeam, beech). Make sure that seal residues do not get into the air, oil and coolant channels.
At the junction of the cylinder head with the timing case cover, apply an elastic sealing compound such as Drei Bond 1209 (arrow, fig. 4.48).
Check the centering sleeves for damage and correct installation. Replace the cylinder head gasket by installing it on the dowel sleeves.
Attention! For the cylinder head with a machined sealing surface, install a thicker (by 0.3 mm) sealing gasket.
Do not wash off the surface coating of new cylinder head bolts. Insert the bolts and tighten them by hand, crosswise, starting from the middle and moving to the edges of the block head. Using a manometric wrench and tool «00.9.120», tighten the bolts (M10) in sequence 1 - 10 (see fig. 4.47) in three consecutive steps:
- 1st reception, torque 30 Nm (3.0 kgf·m);
- 2nd reception, turn at an angle of 80°:
- 3rd reception, tighten by an angle of 80°.
Install chain guide bolt (see fig. 4.46) and tighten it.
Attention! When exposing camshafts, exclude their damage, use a modified key.
Rotate the camshafts until the alignment marks on the shafts («A5–8», «E5–8», arrows, fig. 4.49), will not face up.
Install fixtures «11.2.446/442» (see fig. 4.45) on the camshafts on the bank of cylinders 5-8.
Using a modified wrench (fig 4.50),
center the camshafts so that the tools «11.2.446/442» adjoined to the head of the block without gaps. Install fixture «11.2.443» on adaptation «11.2.446/442» and fix it with bolts «11.2.444», screwed into the spark plug socket.
Pull the drive chain up and keep it taut. Rotate the crankshaft from 45°to TDC in the direction of rotation to TDC at the end of the compression stroke. Lock the crankshaft at TDC with a lock «11.5.180» (see fig. 4.43).
Attention! At the end of the engine assembly, do not forget to remove the retainer.
Install the VANOS assembly on the left cylinder block. Assemble the engine, while replacing the bolt gasket (M14x1.5) drain hole of the engine block and tighten it to 25 Nm (2.5 kgf·m). Bleed the cooling system and check for leaks.
Replacing the right cylinder head
Cylinders 1–4 belong to the right head of the block and its removal must be carried out in a similar technological sequence, taking into account the fact that before removing the intake manifold, the cooling system fan and its drive clutch must be removed.
Rotate the camshafts until the alignment marks on the shafts («A1–4», «Е1–4», arrows, fig. 4.51) will not be turned upwards, by analogy with Fig. 4.49.