Attention: This chapter contains special features that are unique to this engine series. For general information on minor engine repairs, see the previous chapters of this book.
The gearbox is not removed. Remove the coolant manifold between the cylinder heads at the rear.
Remove the intake manifold. Remove the ignition cables with the distributor cap.
Remove the cylinder head covers.
Remove the distributor slider, adapter and distributor housing.
Turn the crankshaft to the TDC position of the piston of the first cylinder and block it with a rotation tool.
Loosen the camshaft drive chain.
Remove the camshaft sprocket top cover.
Remove the middle bar of the chain guide.
Loosen the left damper bar and remove it from the guide.
Remove the camshaft chain sprockets.
Remove the rear of the upper camshaft sprocket box. Keep track of the free guides.
Loosen the cylinder head bolts from outside to inside in the reverse order shown, and remove the heads.
Place the heads on the sealing surfaces. The heads must always lie in this way, otherwise oil will pour out of the hydraulic tappets.
Installation
Degrease the gasket surfaces.
For precise installation, make guide pins from 4 old head bolts. To do this, cut off the heads of the bolts and saw through the slots for a screwdriver.
Screw the guide pins into the outer holes for the head (inlet side).
Take the head gaskets out of the packaging and place them on the block.
Attention: Both gaskets must be removed from the packaging immediately before installation. The coating of the gaskets oxidizes very quickly, because of this, the safety of the gaskets suffers.
Make sure that the crankshaft is in the TDC position of the piston of the first cylinder.
Install the head camshafts as shown. The dowel pins point inward.
Bring the camshaft into the installation position.
In this position, install the heads and tighten the bolts by hand (clean and lightly oiled).
Use bolts instead of guide pins.
Install the rear of the camshaft box with guide bushings. Tighten the bolts by hand.
Tighten the cylinder head bolts in the sequence shown in the figure.
- 1st reception - with a force of 15 Nm, a pause of 15 minutes.
- Step 2 - Tighten 120°.
Fasten the upper timing gear box with a force of 10 Nm. First the vertical bolts, then the rest. Install the camshaft chain with sprockets so that the chain can be adjusted in the area of the bolt splines. Tighten the bolts by hand.
Install damper bars.
Adjust the chain tensioner:
- Loosen the set screw completely.
- Rotate the engine in the direction of travel one revolution.
- Measure A.
Push the tensioner bar all the way against the force of the spring.
Measure dimension B. The difference should be A-B = 6±0.5 mm.
Install the set screw and tighten the lock nut.
Align the camshafts with a feeler gauge and tighten the chain sprockets to 10 Nm.
After cranking the engine two more revolutions, check the installation position of the camshafts again. Correct if required.
Install the outer top cover of the camshaft box.
Center the distributor cap on the camshaft with special tool 11 3 220.
Install adapters and tighten to 24 Nm. Take note of the center pin.
Install the distributor sliders. Tightening torque 6 Nm.
Install the distributor caps with ignition wires.
Attach the exhaust manifold to the pipeline.
Fill the cooling system and remove air from it.
Check engine operation while driving.