Cylinder Head Assembly: Service and Repair
11 12 100 Removing and installing/sealing cylinder head W10
Special Tools Required:
- 00 9 120
- 11 8 200
- 11 8 250
- 11 8 370
- 13 5 280
- 33 2 140
Necessary preliminary tasks:
- Drain coolant.
- Remove wheel arch liner.
- Disconnect battery.
- Remove battery container.
- Remove tank vent valve with line.
- Remove cylinder head.
- Disconnect plug connector from DME.
- Remove cover from fuel rail.
- Release fuel injector wiring harness and place to one side.
- Detach heating hoses on cylinder head.
- Detach top water hose on thermostat.
- Unfasten exhaust manifold.
- Remove spark plugs.
Caution!
- Fit new cylinder head screws.
- Do not wash off bolt coating.
- There must be no oil or coolant in the pocket holes (risk of cracking).
- The fuel in the fuel lines is under pressure (approx. 3 bar). Catch and dispose of escaping fuel.
Remove fuel line from fuel rail; to do so, disconnect quick-release coupling (1) and connect special tool 13 5 280 to fuel rail and fuel line.
Unclip both lines on stabilizer bar bracket.
Detach vacuum line to brake booster from manifold and unclip from holder.
Press ring downwards to expose line (1).
Disconnect plug connector of camshaft sensor.
Remove dipstick.
Remove intake manifold screws (5-1).
Lift intake manifold over dipstick tube.
Disconnect line from filler neck to expansion tank, then the engine wiring harness can be moved around the thermostat housing.
Installation note: Tightening torque 26 Nm.
Tie back intake manifold.
Note: See illustration.
Remove screws (1) for stabilizer bar bracket.
Remove stabilizer bar bracket.
Tightening torque 100 Nm.
Detach oxygen sensor plug connector (1).
Remove holder for oxygen sensor plug connector from cylinder head (2).
Remove retaining screw (3) of coolant distributor pipe.
Detach plug connector (4) of coolant temperature sensor.
Support engine with trolley jack and a rubber pad on oil sump.
Caution! Risk of damage to oil sump.
Remove bolts (1) for engine carrier and unscrew
retaining nut (2) for engine mount.
Remove engine carrier.
Remove hydraulic engine mount with special tool 11 8 200.
Tightening torque 100 Nm.
Mount special tool 11 8 370 on cylinder block and body fixtures.
Note: See illustration.
Remove camshaft sensor (1).
Release screw plugs (2).
Tightening torque 18 Nm.
Rotate crankshaft until triangular adjustment mark on camshaft gear (2) is at 12 o'clock.
Important: For assembly, mark timing chain at triangular adjustment mark (2) with paint (1).
Mark vibration damper and timing case cover with paint.
Note: See illustration.
Installation note: The brass-colored links are of no importance to the timing.
Secure special tool 11 8 250 to camshaft gear.
Slacken central bolt (1).
Caution! Do not remove central bolt (1) yet.
Remove wiring harness holder (1).
Release timing chain tensioner (2).
Note: Remove clamping fixture.
Unscrew central bolt for camshaft gear.
Remove camshaft gear from timing chain and secure timing chain to prevent it dropping down.
Release screws (1).
Remove clamping rail and chain guides (2).
Note: Shown without timing chain cover for purposes of clarity. This illustration shows the layout of the timing chain guides
Note: The timing chain cover is designed in such a way that the timing chain can remain on the crankshaft gear without gear teeth being skipped.
Do not rotate crankshaft.
Installation note: Multilayer steel cylinder head gasket (MLS) require a scratch-free sealing surface, therefore proceed with care when cleaning aluminium engine components.
Clean all engine oil ducts.
Release cylinder head mounting elements 11 and 12.
Slacken cylinder head bolts (1 to 10) working from outside in.
Remove cylinder head.
Caution! Do not rest cylinder head on sealing surface.
Risk of damage to valves.
Use a commercially available straight edge to check the diagonal and horizontal surface evenness of the cylinder head.
Max. permitted cylinder head distortion is 0.1 mm.
Installation note:
Check dowel sleeves (1) for damage and replace if necessary.
The must be no oil or coolant in the tapped holes for the cylinder head bolts in the cylinder block.
If necessary, clean out holes with compressed air.
Replace cylinder head gasket.
Pay attention to adjustment (1) of cylinder head gasket.
Install cylinder head.
Insert cylinder head bolts (1 to 10) and tighten down in sequence (1-10).
Tightening torque:
1st stage: 40 Nm
2nd stage: 90°
Insert cylinder head bolts (11 to 12) and tighten down in sequence (11-12).
Tightening torque: 28 Nm.
Tighten down cylinder head bolts with special tool 00 9 120.
Install clamping rail and chain guides (2).
Install retaining screws (1) of guides.
Tightening torque: 28 Nm.
Place timing chain on camshaft gear.
Screw in central bolt.
Note: Shown without timing chain cover for purposes of clarity. This illustration shows the layout of the timing chain.
Installation note: Align camshaft and timing chain markings to each other.
Insert central bolt.
Fit special tool 11 8 250.
Caution! Risk of damage to timing chain.
Tighten down central bolt (1).
Tightening torque: 102 Nm.
Move timing chain tensioner into transition position.
Place clamping fixture (1) on a level surface.
Remove cap (2) from clamping fixture.
Place palm of hand against clamping fixture and exert continuous pressure until clamping fixture is completely compressed.
Replace cap (2) on clamping fixture.
Install timing chain tensioner.
Tighten down screw plug (2).
Installation note:
Tightening torque: 63 Nm.
Install cable holder (1).
Caution! Timing chain tensioner (1) is in transition position.
Note: Make sure timing chain is correctly arranged inside channel of timing chain guides.
Lever at clamping rail with special tool 33 2 140 until timing chain tensioner tensions timing chain.
Do not lever directly at timing chain. Risk of damage to timing chain.
Note: Shown without timing chain cover for purposes of clarity. This illustrations shows the layout of special tool 33 2 140.
Pay attention to release position of clamping fixture (1).
Assemble engine.
Fill cooling system and check for leaks.
Replace engine oil if necessary.
Check function of DME.