Cylinder Head
Cylinder Head
Special tools, testers and auxiliary items required
• Lifting tackle (3033)
• Shop crane (VAS 6100)
• Sealant
Removing
• Engine installed.
• During installation, all cable ties must be reinstalled at the same location.
There is a risk of injury because fuel is under very high pressure.
• Before opening high pressure components of the fuel injection system, pressure must be relieved to residual pressure.
- Reduce fuel pressure in high pressure area => [ Releasing Fuel Pressure on High Pressure Side ] Service and Repair.
- Drain coolant => [ Cooling System, Draining and Filling ] Service and Repair.
- Remove intake manifold
- Remove cylinder head cover => [ Cylinder Head Cover ] Service and Repair.
- Remove timing chain upper cover => [ Upper Timing Chain Cover ] Upper Timing Chain Cover.
- Remove camshaft timing chain from camshafts => [ Camshaft Timing Chain, Removing from Camshafts ] Camshaft Timing Chain, Removing From Camshafts.
- Remove ribbed belt tensioner => [ Ribbed Belt Tensioner ] Service and Repair.
Risk of injury from fuel.
• To reduce residual pressure in fuel system, lay a clean cloth around connector and carefully loosen connector.
- Remove fuel supply line - 2 -.
• Ignore - 1 -.
- Disconnect electrical connector - 2 - for low fuel pressure sensor (G410) at top of high pressure pump.
• Ignore - 1 -.
• Depending on version, the low fuel pressure sensor (G410) sits on the bulkhead.
- Disconnect electrical connector - arrow - for fuel metering valve (N290) at bottom of high pressure pump.
- Disconnect electrical connectors - arrows - on fuel injectors.
• Ignore - 1 through 7 -.
- Free up B+ wire to starter on left rear engine lifting eye.
- Remove bolts - arrows - on coolant connecting pieces.
• Ignore - 1, 2, 3 -.
- Remove bolts - arrows - and remove heat shield.
- Remove bolt - arrow - and remove ground (GND) wire.
- Roll up heat insulation sleeve - 1 - and remove coolant hose from cylinder head.
- Remove bolts - 2 - on main primary converter brackets.
• Ignore - 1 -.
- Remove nuts - arrows - and remove primary catalytic converters from threaded pins.
- Loosen and tighten cylinder head bolts in - 1 to 20 - sequence.
- Engage lifting tackle (3033) as follows:
• Belt pulley side: Position "3".
• Transmission side: Position "11".
- Carefully raise cylinder head.
Risk of contaminating cylinder wall and piston.
• Place clean cloths in cylinder.
Installing
• Tightening specifications => [ Cylinder Head Tightening Sequence ] Cylinder Head and Cover, Assembly Overview, => [ Exhaust Manifold, Assembly Overview ] Exhaust Manifold, Assembly Overview.
Risk of damaging sealing surfaces.
• Carefully remove sealant residue from cylinder head and cylinder block.
• Make sure that no long scrapes or scratches result.
Risk of damaging cylinder block.
• There must be no oil or coolant in the blind holes for the cylinder head bolts in the cylinder block.
Risk of cylinder head seal leaking.
• Carefully remove all grinding and sanding residue.
• Only unpack new cylinder head gasket immediately prior to installation.
• To prevent cylinder head seal silicone layer and recessed area from being damaged, always handle seal extremely carefully.
Risk of damaging open valves.
• If a replacement cylinder is installed, only remove plastic base right before cylinder head is installed to protect open valves.
Risk of damaging valves and piston heads after working on valvetrain.
• To ensure valves do not strike pistons when starting, carefully rotate engine at least 2 full revolutions.
• Replace bolts which have been tightened to torque.
• Replace sealing rings, seals and self-locking nuts.
• Note different sealant for cylinder head sealing surfaces and bolts.
• If a replacement cylinder is installed, contact surfaces between bearing elements, roller rocker levers and cam running surfaces must be lubricated before installing cylinder head cover.
• Secure all hose connections using hose clamps appropriate for the model type.
- Position camshafts at "TDC" before cylinder head is installed.
• Camshaft bar (T10068 A) must be situated in grooves in both camshafts.
- Check again if crankshaft is at "TDC" marking.
• Markings on vibration damper and sealing flange must align - arrow -.
- Check whether fitting sleeves are inserted in cylinder block - arrows -.
- Apply a sealant bead - arrows - to clean sealing surfaces on cylinder block joint and timing chain cover.
• Thickness of sealant beads: 2.0 mm.
Risk of plugging oil pump strainer with excess sealant.
• Do not apply sealant bead thicker than indicated.
- Immediately apply cylinder head seal.
• Installed location: Part no. must be visible.
- Always put some sealant in both of 3 mm holes that lie on sealant bead.
- Set cylinder head in place.
- Apply sealant in area - 1 - of cylinder head bolts.
- Insert long bolts in center bores in cylinder head.
- Tighten cylinder head bolts => [ Cylinder Head Tightening Sequence ] Cylinder Head and Cover, Assembly Overview
• Do not retighten cylinder head bolts after repairs.
- Install camshaft timing chain => [ Installing (Adjusting Valve
Timing) ] Camshaft Timing Chain, Removing From Camshafts.
- Install cylinder head cover => [ Cylinder Head Cover ] Service and Repair
- Install primary catalytic converters => [ Primary Catalytic Converters ] Primary Catalytic Converters.
- Install intake manifold
- Change engine oil.
- Replace coolant => [ Cooling System, Draining and Filling ] Service and Repair.