Engine Installed

Removing suction-filter housing with air-mass sensor, refer to Powertrain Management.
Removing gear-case cover, top, refer to Timing Components.
Removing all spark plugs, refer to Powertrain Management.





Drain coolant from engine block.
Installation:
Replace sealing ring.
Tightening torque, refer to Engine, Specifications.

Removing exhaust pipe from exhaust manifold, refer to Exhaust System, Service and Repair
Removing lower section of manifold, refer to Intake Manifold, Service and Repair.
Remove the hydraulic chain tensioner, refer to Timing Components.

Release water hose from rear branch flange.
Disconnect heater feed and return hoses.

Removal
Removal of cylinder head is described separately from installation.
Assembly sequence for removal and installation is different.





Turn central screw to rotate crankshaft in normal direction of rotation until piston of first cylinder is at firing TDC.





Note: At firing TDC, alignment bores are pointing upwards.





Position camshaft with Special Tool 11 3 240 in firing TDC position of first cylinder.





Remove the chain wheels.





Release the slide rail from the cylinder head.





Turn the adjusting screw of the slide rail back approx. two revolutions.

Caution:
Turn the engine back approx. 45° on the central screw.
This prevents contact between valves and pistons.





Note: Use Special Tool 11 2 250.

Release cylinder-head bolts in sequence 10 through 1.
Remove cylinder head and cylinder-head seal.

Installation
Installation of cylinder head is described separately from removal.
Assembly sequence for removal and installation is different

Clean sealing faces of cylinder head and engine block; if necessary, remove traces of sealing compound with hardwood spatula
Ensure that no gasket debris drops into the oil and coolant ducts.





Check that dowel sleeves are undamaged and correctly located.
Replace cylinder-head seal and rubber-profile seal.

Caution:
Use cylinder-head bolts once only.
Threaded bores in engine block must be free of dirt and oil.

Note: Risk of cracking, incorrect tightening values.





Put the cylinder head on.
Install the new cylinder-head bolts (lightly oiled).
For torsion angle adjustment, use Special Tool 00 9 120 or Special Tool 11 2 110.





Tighten down the cylinder-head bolts in order 1 through 10.
Tightening torque, refer to Engine, Specifications.





Place the adjusting screw of the slide rail free of play on the cylinder head.





Insert the screw and tighten down the slide rail.





Locate camshaft with Special Tool 11 3 240 in firing TDC position of first cylinder.





Note: At firing TDC, alignment bores are pointing upwards.





Remove dust cover from locating bore.





Rotate engine from 45° before TDC position engine-wise until in TDC position.
Secure crankshaft in TDC position with Special Tool 11 2300.

Caution: Remove Special Tool 11 2 300 before starting engine.





Place the chain with the chain wheels.

Note: Arrow on chain wheel in cylinder axis points up.

Align long bores centrally.





Place the sensor gear onto the inlet chain wheel.

Note: Arrow on sensor gear in cylinder axis points up.





Insert all chain wheel screws and tighten so that they are free of play; the chain wheels remain loose.

Install hydraulic chain tensioner.

Caution: Note installation instructions, refer to Timing Components.





Tighten down the chain wheels.
For tightening torque, refer to Engine, Specifications.
Remove Special Tools 11 2 300 and 11 3 240.
Assemble engine.