VALVETRAIN Overview
Only remove the plastic protectors installed to protect the open valves immediately before positioning the cylinder head.
When replacing the cylinder head or cylinder head gasket, the coolant must be completely replaced.
Cylinder heads with cracks between the valve seats can continue to be used without reducing service life, as long as the cracks have a Max. width of 0.5 mm.
After installing the camshafts, the engine may not be started for approximately 30 minutes. The hydraulic equalization elements must seat themselves (otherwise the valves will crash into the pistons).
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.
Always replace gaskets and seals.
- Seal
- Do not additionally oil or grease the sealing lip of the seal.
- Before installing, remove any remaining oil from the camshaft journal with a clean cloth.
- To install, tape over the groove on the camshaft taper.
- Removing and installing, refer to CAMSHAFT SEAL .
- Bolt
- 10 Nm
- Nut
- 10 Nm
- Bearing Frame
- Follow the sequence for loosening and tightening CAMSHAFTS .
- Seal using silicone adhesive Sealant D 176 501 A1.
- Exhaust Camshaft
- Removing and installing, refer to CAMSHAFTS .
- Intake Camshaft
- Removing and installing, refer to CAMSHAFTS .
- Roller Rocker Lever
- Mark the installed position.
- Do not interchange.
- Check the roller for ease of movement.
- Lubricate the running surfaces before installing.
- Hydraulic Lash Adjusters
- Mark the installed position.
- Do not interchange.
- Lubricate the running surfaces before installing.
- Valve
- Mark the installed position.
- Do not grind, only hand lapping is permitted.
- Valve dimensions, refer to Fig 2.
- Checking valve guides, refer to VALVE GUIDE, CHECKING .
- Cylinder Head
- See the note above.
- Checking for distortion, refer to Figure.
- Removing and installing, refer to CYLINDER HEAD .
- All of the coolant must be replaced after installation.
- Valve Stem Seal
Replacing, refer to VALVE STEM SEALS, CYLINDER HEAD INSTALLED .
- Valve Spring
- Valve Spring Plate
- Valve Retainers
- Cap
- Always replace.
- Drive in using a suitable drift until it is flush.
Intake and exhaust valves must not be refaced by grinding. Only hand lapping is permitted.
| Dimension | Intake Valve | Exhaust Valve | |
|---|---|---|---|
| diameter a | mm | 26.60 | 26.00 |
| diameter b | mm | 5.940 | 5.940 |
| c | mm | 99.30 | 99.10 |
| α | ° angle | 45 | 45 |