Camshafts

Camshafts

• 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 tears have a width of max. 0.5 mm.

• After installing the camshafts, the engine may not be started for approximately 30 minutes. The hydraulic adjusting elements 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 gaskets and seals.

Special tools, testers and auxiliary items required

• Securing pin (3359)

• Counter-holder tool (T10051)

• Removal tool (T10052)

• Camshaft insertion tool (T40094)

• Camshaft clamping tool (T40095)

• Camshaft tensioning tool (T40096)

• Torque Wrench (V.A.G 1331)

• Torque Wrench (V.A.G 1332)

• Hand drill with plastic brush attachment

• Protective eyewear

• Silicone adhesive sealant (D 176 501 A1)

Removing

- Remove toothed belt from the camshaft and high pressure fuel pump. Refer to --> [ Toothed Belt, Removing, Installing and Tensioning ] Toothed Belt, Removing, Installing and Tensioning.

- Remove cylinder head cover. Refer to --> [ Cylinder Head Cover ] Cylinder Head Cover.

- Remove bolts - 1 - for camshaft sprocket.





- Remove camshaft sprocket from the hub.

- Counterhold hub with the counterhold tool (T10051) and loosen hub bolt - 1 -.





- Remove bolt for hub by approximately 2 turns.

- Position puller (T10052) and align it to the bores in the hub.





- Tighten mounting bolts - 1 -.

- Tension hub by tightening puller (T10052) - 2 - evenly until it can be removed from the camshaft taper.

• Hold puller (T10052) with a 30 mm wrench.

- Remove hub from the cone of the camshaft.

- Remove vacuum pump. Refer to --> [ Vacuum Pump ] Service and Repair.

- Remove bearing frame bolts or nuts in the sequence - 24 to 1 -.





- Remove bearing frame.

- Carefully remove camshafts.

Installing

• Note the expiration date of the sealant.

• Seal separating surfaces between the bearing frame and cylinder head with silicone adhesive sealant (D 176 501 A1).

CAUTION!
• Only install the camshafts with the camshaft insertion tool (T40094) as described below. Otherwise the axial bearing in the bearing frame will be destroyed and the cylinder head will have to be replaced.

• Make sure that no sealant residue enters the cylinder head and bearings.

CAUTION!
Wear safety glasses.

- Using rotating plastic brush, remove any remaining sealant from cylinder head and guide frame.

- Clean sealing surfaces, they must be free of oil and grease.

- Oil journal surfaces of camshafts.

Assemble camshaft insertion tool (T40094) as follows:

- Remove mounts (T40094/3), (T40094/4) and (T40094/5) from base plate. Loosen threaded connections from below.





• If the mounts on the camshaft insertion tool (T40094) are not marked, mark the removed mounts, for example with numbers, to ensure it can be assembled later.

- Install mounts (T40094/9) and (T40094/10) in the empty outer locations.





- Position mount (T40094/2) on location " A" and mount (T40094/1) on location " F".

- Insert intake camshaft first as illustrated. Make sure the indentation - arrow - for the cylinder head bolt faces "outward".





- Position 0.50 mm feeler gauge and slide the mount (T40094/8) into groove on the intake camshaft.

- Insert exhaust camshaft.

- Secure exhaust camshaft at its groove - arrow - with cover (T40094/11).





- Position tensioning tool (T40096/1) on the exhaust camshaft sprockets.

CAUTION!
Make sure the clamping jaw marked with an arrow is on the wider sprocket.

- Tighten tensioning tool (T40096/1) with thumb wheel until the tooth faces align. Use a 13 mm open end wrench if necessary.





- Slide intake camshaft toward the exhaust camshaft until the splines engage.

- Position bearing frame on the camshafts.

• All the camshaft bearings must lie on the camshafts.

- Position clamping tool (T40095) as illustrated and secure the camshafts in the bearing frame.





- Remove cover (T40094/11).

- Remove mount (T40094/8) from the intake camshaft groove.

- Cut tube nozzle at front marking (nozzle dia. approximately 3 mm).





- Apply silicone sealant to the clean sealing surface of the cylinder head as illustrated. The sealing compound bead must be:





• 2 to 3 mm thick

• Apply on the inner side in the area with the threaded holes

• The sealant beads must not be thicker than 2 to 3 mm or excess sealant can enter the camshaft bearing.

- Remove camshafts with bearing frame and the clamping tool (T40095) from the camshaft insertion tool (T40094).

- Carefully insert the camshafts and bearing frame in the cylinder head.

- First tighten bearing frame bolts or nuts by hand in sequence - 1 to 24 -.





• The guide frame must be in contact with the entire contact surface of the cylinder head.

- Tighten bearing frame bolts or nuts in sequence - 1 to 24 -.

• Tightening specifications --> [ 2 10 Nm ] Valvetrain Assembly Overview and --> [ 3 10 Nm ] Valvetrain Assembly Overview.

- Remove clamping tool (T40095) and tensioning tool (T40096/1).

- Replace camshaft seal. Refer to --> [ Camshaft Gasket ] Service and Repair.

- Drive a new sealing cover --> [ (item 15) Cap ] Valvetrain Assembly Overview onto cylinder head with a suitable drift until it is flush.

The rest of installation is in reverse order of removal, noting the following:

• After installing the camshafts, the engine may not be started for approximately 30 minutes. The hydraulic adjusting elements must seat themselves (otherwise the valves will seat themselves on the pistons).

• After working on the valvetrain, carefully rotate engine by hand at least 2 full revolutions to ensure that valves do not strike the pistons when starting.

- Place hub on the camshaft.

- Counterhold hub with the counterhold tool (T10051) and tighten hub bolt - 1 -.





• Tightening specifications --> [ 11 100 Nm ] Toothed Belt Drive Assembly Overview.

- Push camshaft sprocket onto hub.

• The toothed segment - arrow - of the camshaft sprocket must face upward.





- Install bolts - 1 - into camshaft sprocket by hand to eliminate play.

- Lock hub with rig pin (3359).

- How to install and tension the toothed belt. Refer to --> [ Toothed Belt, Removing, Installing and Tensioning ] Toothed Belt, Removing, Installing and Tensioning.

- Install vacuum pump. Refer to --> [ Vacuum Pump ] Service and Repair.

- Install cylinder head cover. Refer to --> [ Cylinder Head Cover ] Cylinder Head Cover.