VALVETRAIN Overview

WARNING: This page is about a different car, the 2013 Volkswagen Jetta and 2012 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

The cylinder head and the cylinder head cover must be replaced together.

Do not start the engine for approximately 30 minutes after installing the camshafts. The hydraulic lash adjusters must seat themselves (otherwise the valves will seat themselves on 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 the gaskets and seals.

Fig 1: Identifying Valvetrain Overview

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Exhaust Valve
- Do not rework, only lapping is permitted.
- For the correct valve dimensions, refer to Fig 3.
- Checking the valve guides. Refer to VALVE GUIDE, CHECKING .
Cylinder Head
Valve Guide
- Checking, refer to VALVE GUIDE, CHECKING .
Valve Stem Seal
- Removing and installing, refer to VALVE STEM SEALS .
Valve Spring
Spring Plate
Valve Retainers
Roller Rocker Arm with Hydraulic Lash Adjuster
- Do not interchange.
- Lubricate the contact surfaces.
Exhaust Camshaft
- Removing and installing, refer to CAMSHAFTS .
- Checking the axial play. Refer to CAMSHAFT AXIAL CLEARANCE, CHECKING .
- Check the radial clearance using Plastigage (roller rocker arm arms are removed).
- Radial clearance at the bearing (24 mm diameter): 0.024 to 0.066 mm.
- Radial clearance at the bearing (32 mm diameter): 0.030 to 0.051 mm.
- Run out: Max. 0.04 mm.
Cylinder Head Cover
- With integrated camshaft bearings.
- Clean the sealing surface, reworking is not permitted.
- Remove the old sealant residue.
Bolt
- Always replace.
- Tightening sequence and specification, refer to Fig 2.
Plug
- 5 Nm
- With a ball head for the engine cover.
O-ring
- Always replace.
- Lubricate with engine oil.
Plug with O-ring
- Always replace.
- Lubricate the O-ring with engine oil.
Intake Camshaft
- Removing and installing, refer to CAMSHAFTS .
- Checking the axial play. Refer to CAMSHAFT AXIAL CLEARANCE, CHECKING .
- Check the radial clearance using Plastigage (roller rocker arms are removed).
- Radial clearance at bearing (24 mm diameter): 0.024 to 0.066 mm.
- Run out: Max: 0.04 mm.
Cap
- Always replace.
- Removing: With the cylinder head cover installed, pierce through one side of the cap with an awl and pry it out.
- Installing: Without sealant, press it in 1 to 2 mm using the thrust piece T10174.
Intake Valve
- Do not rework, only lapping is permitted.
- For the correct valve dimensions, refer to Fig 3.
- Checking the valve guides. Refer to VALVE GUIDE, CHECKING .

Fig 2: Identifying Cylinder Head Cover - Tightening Sequence

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Special tools and workshop equipment required

Torque Wrench (5-50 Nm) V.A.G 1331

Procedure

-- Tighten the new cylinder head cover bolts in 3 passes in sequence -1 through 6- as follows:

-- Tighten the bolts by hand.

-- Tighten the bolts to 8 Nm.

-- Tighten the bolts an additional 90° (1/4).

NOTE:

Ensure the cylinder head cover is not tilted.

Fig 3: Identifying Valve Dimensions

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

NOTE:

Intake and exhaust valves must not be refaced by grinding. Only lapping is permitted.

Dimension		Intake Valve	Exhaust Valve
Diameter a	mm	33.85 ± 0.10	28.00 ± 0.1
Diameter b	mm	5.980 ± 0.007	5.955 ± 0.007
c	mm	103.97	101.87
α	∠°	45	45