Cylinder Head Assembly: Service and Repair
Cylinder Head
Cylinder heads can only be removed and installed with engine removed.
Special tools, testers and auxiliary items required
• Torque wrench (VAG 1331)
• SW 17 socket (VAG 1331/6)
• SW 14 socket, open ring (VAG 1331/8)
• Multi point socket (T10070)
Removing
• Removal and installation of the left cylinder head is depicted in the following procedure.
• All cable ties opened or removed during engine removal must be reinstalled at the same locations during installation.
- Drain the cooling system. Refer to => [ Cooling System, Draining and Filling ] Cooling System, Draining and Filling.
- Remove engine. Refer to => [ Engine, Removing ] Engine, Removing.
- Separate engine and transmission. Refer to => [ Separating transmission from engine ] Engine, Removing.
- Remove left primary catalytic converter. Refer to => [ Left Primary Catalytic Converter ] Left Primary Catalytic Converter.
- Remove electrical connectors - 1 - and - 2 - for knock sensor 3 (G198) and knock sensor 4 (G199) from bracket.
- Remove air guide hose to Secondary Air Injection (AIR) combination valves - arrows -.
- Remove intake manifold.
Vehicles with aluminum intake manifolds, refer to => [ Intake Manifold ] Intake Manifold.
Vehicles with plastic intake manifolds, refer to => [ Intake Manifold ] Intake Manifold.
- Remove left coolant pipe.
- Remove right coolant pipe.
- Remove rear coolant pipe.
- Remove camshaft timing chains from camshafts.
- Remove bolts - 1 - and - 2 - and remove right chain tensioner.
With Aluminum Intake Manifold
- Disconnect electrical connectors - arrows - at fuel injectors.
- Remove high pressure line - 2 - from connector on fuel rail.
- Remove high pressure line - 1 - from connector on fuel rail. To do this, counterhold at hex with and open end wrench and loosen the union nut.
• Do not change the angles of the high pressure lines.
With Plastic Intake Manifold
- Disconnect the connectors - arrows - and the vacuum hose - 1 -.
- Remove the fuel pipe bolts - 1 -.
- Remove the union nuts - 2 and 3 -. Counter hold on the hex with an open end wrench.
- Remove the fuel pipe.
Continuation for All
- Remove locking bolt - arrow -.
- Remove the bolts - arrows -.
- Loosen cylinder head bolts - 1 through 10 - using the polydrive bit and drive socket (T10070) in sequence.
- Remove cylinder head bolts and carefully remove cylinder head.
- Lay cylinder head on a soft surface (foam).
Installing
• Replace cylinder head bolts.
• During assembly, replace self locking nuts and bolts.
• Always replace bolts that have been tightened to specifications as well as O-rings and gaskets.
• Carefully remove sealant residue from cylinder head and cylinder block. Make sure that no long scrapes or scratches result.
• Carefully remove all grinding and sanding residue.
• There must be no oil or coolant in the blind holes for the cylinder head bolts in the cylinder block.
• Only unpack new cylinder head gasket immediately prior to installation.
• Handle gasket carefully. Damages to the silicone layer and in areas of recesses may result in leaks.
• Cylinder heads with cracks between the valve seats, or between the valve seat and the spark plug threads, can continue to be used without reducing the service life, as long as the cracks have a max. width of 0.3 mm, or only the first 4 threads of the spark plug threads are cracked.
• After installing a replacement cylinder head with camshafts installed, oil contact surfaces between roller rocker levers and cam lubricating surfaces after installing cylinder head.
• Do not remove plastic bases protecting freed up valves until immediately before installing cylinder head.
• Secure all hose connections with hose clamps appropriate for the model.
• During installation, all cable ties must be reinstalled at the same location.
• After working on the valvetrain and lifters, carefully rotate the crankshaft by hand at least 2 full revolutions before starting to be sure that valves do not strike the pistons.
• When replacing the cylinder head or cylinder head gasket, coolant must be completely replaced.
- Check whether camshafts of both cylinder heads stand in Top Dead Center (TDC) position.
• Camshaft clamp (T40070) must be installed on both cylinder heads and the bolts tightened to 25 Nm.
• Crankshaft holder (3242) must be installed.
- Position cylinder head gasket.
• Pay close attention to alignment pins in cylinder block - arrows -.
• Pay attention to installation position of cylinder head gasket, marking "oben" (top) or part number must face up towards cylinder head.
- Install cylinder head.
- Insert new cylinder head bolts and tighten by hand.
- Tighten cylinder head bolts - 1 through 10 - in 4 stages in sequence as follows:
- Using a torque wrench, tighten to 30 Nm.
- Using a torque wrench, tighten to 60 Nm.
- Using a wrench, tighten an additional 90° (1/4 turn).
- Using a wrench, tighten an additional 90° (1/4 turn).
• There is no requirement to retighten the cylinder head bolts after repairs.
- Insert bolts - arrows - with locking compound and tighten to 8 Nm; for locking compound.
- Tighten bolts - arrows - an additional 90° (1/4 turn) using a wrench.
- Tighten locking bolt - arrow -.
- Check whether camshaft timing chain tensioner guide rail is secured with locking pin (T40071).
• If the tensioning element is to be removed from the chain tensioner, observe the installed position: Hole in housing floor faces toward chain tensioner, piston faces toward tensioning rail.
• Disregard - arrow -.
- Clean chain tensioner oil screen - 2 - if necessary.
- Place a new gasket - 3 - onto the rear of the chain tensioner - 1 -.
- Set the chain tensioner in place and install the camshaft timing chain, as shown in the illustration.
- Tighten bolts - 1 - and - 2 -.
The rest of the installation is performed in reverse order of removal, noting the following:
- Install camshaft timing chains. Refer to => [ Installing ] Service and Repair.
- Install left and right timing chain covers. Refer to => [ Installing ] Service and Repair.
- Install rear coolant pipe. Refer to => [ Rear Coolant Pipe ].
- Install left coolant pipe. Refer to => [ Left Coolant Pipe ].
- Install right coolant pipe. Refer to => [ Right Coolant Pipe ].
- Install cylinder head cover.
- Install the intake manifold.
Vehicles with aluminum intake manifold.
Vehicles with plastic intake manifold.
- To tighten SW 14 union nut at fuel rail, use torque wrench (VAG 1331) with socket Insert AF 14, open ring (VAG 1331/8).
- To tighten SW 17 union nut at fuel rail, use the torque wrench (VAG 1331) with SW 17 socket (VAG 1331/6).
- Install left primary catalytic converter. Refer to => [ Left Primary Catalytic Converter ] Left Primary Catalytic Converter.
- Install engine. Refer to => [ Engine, Installing ] Engine, Installing.
- Align exhaust system free of tension. Refer to => [ Exhaust System, Installing ] Service and Repair.
- Replace coolant. Refer to => [ Cooling System, Draining and Filling ] Cooling System, Draining and Filling.
Tightening Specifications
