Valve Guide Seal: Service and Repair
Valve Stem Seals
Special tools, testers and auxiliary items required
• Spark plug removal tool (3122 B)
• Valve seal removal tool (3364)
• Valve stem seal driver (3365)
• Valve cotter disassembly and assembly device (VAS 5161) with guide plate (VAS 5161/26)
• Adapter (T40012)
Procedure
• Engine removed.
- Camshafts, removing => [ Camshafts ] Service and Repair.
- Mark the allocation of the roller rocker lever and hydraulic adjusting elements so they can be installed again.
- If necessary, remove roller rocker levers with hydraulic adjusting elements and place them on a clean surface.
- Remove ignition coils.
- Remove spark plugs with spark plug removal tool (3122 B).
- Move piston for respective cylinder to "Bottom Dead Center " (BDC) position.
- Position drift (VAS 5161/3) on valve spring plate.
- Loosen stuck valve keepers with a plastic hammer.
- Position guide plate (VAS 5161/26) on cylinder head.
- Tighten guide plate with nuts - 1 and 2 - on cylinder head.
- Install adapter (T40012) with sealing ring in respective spark plug thread and hand tighten.
- Connect hose to compressed air.
• Minimum pressure: 6 bar positive pressure.
Outer Valve Row
- Install engaging device (VAS 5161/6) with installation fork (VAS 5161/5) in guide plate as shown in illustration.
- Slide installation cartridge (VAS 5161/8) in guide plate.
- Engage pressure fork (VAS 5161/2) on engaging device and press installation cartridge down.
- At the same time, rotate installation cartridge knurled screw right until points engage in valve keeper.
- Move knurled screw back and forth slightly.
• Valve keepers are pressed against each other and capture in the installation cartridge.
- Release pressure fork.
- Remove installation cartridge.
- Unfasten guide plate and turn it aside.
• Pressurized air hose remains connected.
- Remove valve spring with valve spring plate.
Inner Valve Row
- Install engaging device (VAS 5161/6) with installation fork (VAS 5161/5) in guide plate as shown in illustration.
- Slide installation cartridge (VAS 5161/8) in guide plate.
- Slide knurled spacer ring (VAS 5161/17) onto installation cartridge (VAS 5161/8).
- Slide installation cartridge in guide plate.
- At the same time, rotate installation cartridge knurled screw right until points engage in valve keeper.
- Move knurled screw back and forth slightly.
• Valve keepers are pressed against each other and capture in the installation cartridge.
- Release pressure fork.
- Remove installation cartridge.
- Unfasten guide plate and turn it aside.
• Pressurized air hose remains connected.
- Remove valve spring with valve spring plate.
Procedure for Both Valve Rows
- Remove valve stem seals using valve seal removal tool (3364).
Risk of damage when installing valve stem seals.
• Place plastic sleeve - A - that is attached to valve stem seals - B - on valve stem.
- Lightly oil valve stem seal.
- Slide valve shaft seal onto plastic sleeve.
- Carefully press valve stem seal onto valve guide with valve stem seal drive (3365).
- Remove plastic sleeve.
If valve keepers were removed from installation cartridge, they must next be inserted in valve keeper inserting tool (VAS 5161/18):
• The large diameter of valve keeper point upward.
- Press installation cartridge from above onto valve keeper inserting tool and capture keepers.
- Insert valve spring and valve spring plate.
• Installed location: Large diameter - arrow - on valve spring faces toward cylinder head.
- Fasten guide plate on cylinder head again as shown in illustration.
Outer Valve Row
- Insert installation cartridge in guide plate.
- Press pressure fork down and pull knurled screw up, turning left and right.
• The valve keepers are inserted in this manner.
- Release pressure fork with knurled screw still raised.
Inner Valve Row
- Insert installation cartridge in guide plate.
- Press pressure fork down and pull knurled screw up, turning left and right.
• The valve keepers are inserted in this manner.
- Release pressure fork with knurled screw still raised.
- Repeat procedure on each valve.
Assembling
Assembly is in reverse order of removal, noting the following:
- Install camshafts => [ Camshafts ] Service and Repair.
- Install spark plugs.
- Install ignition coils.
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.