Camshaft: Service and Repair

Camshafts

Special tools, testers and auxiliary items required

• Thrust Piece (T10174)

• Assembly Tool (T10352)

• Counter Hold Tool (T10355)

• Locking Pin (T40011)

• Ignition Coil Puller (T40039)

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

• Silicone Sealant (D 154 103 A1)

• Cable Ties

• Flat Scraper

• Hand Drill with Plastic Brush Attachment

• Protective Eyewear

Removing

• The sealing surfaces of the cylinder head cover and the cylinder head must not be reworked.

• The camshaft bearings are integrated in the cylinder head and the cylinder head cover. The tension must be released from the camshaft timing chain before removing the cylinder head cover.

• If the cylinder head cover was removed, the sealing cap must be replaced.

• All cable ties which are opened or cut off when removing, must be replaced in the same position when installing.


When doing any repair work, especially in the engine compartment, pay attention to the following due to clearance issues:

• Route lines of all types (for example, fuel, hydraulic, Evaporative Emission (EVAP), coolant, refrigerant, brake fluid and vacuum) and electrical wiring so that the original path is followed.

• To prevent damage to the lines, make sure there is sufficient clearance to all moving or hot components.

- Remove the engine cover. Refer to => [ Engine Cover ] Engine Cover.

- Remove the vacuum pump. Refer to => [ Vacuum Pump ] Vacuum Pump.

- Remove the noise insulation.

- Remove the right front wheel.

- Remove the front part of the right wheel housing liner and/or the entire right front wheel housing liner.

- Remove the bolts - arrows -.






- Remove the charge air pipe by lifting the clamps - 1 and 2 -.

- Disconnect the connector - 1 - from camshaft adjustment valve 1 (N205).






- Remove the bolts - arrows - and remove the camshaft adjustment valve 1.

- Remove the upper timing chain cover. Refer to => [ Upper Timing Chain Cover ] Upper Timing Chain Cover.


The control valve has a left hand threads.

- Remove the control valve using the assembly tool (T10352) in the - direction of the arrow -






- Remove the bolts - arrows - and remove the bearing bracket.






- Use the counter hold tool (T10355) to rotate the vibration damper to Top Dead Center (TDC) - arrow -:






• The notch on the vibration damper must line up with the arrow mark on the lower timing chain cover.

- Carefully mark the drive chain/sprockets - arrows - with a waterproof marker. These marks are necessary for reinstallation.






- Remove the plug - arrow -.






- Lift the chain tensioner locking wedge by inserting a scribe or a suitable screwdriver into the hole in the chain tensioner - arrow direction 1 -.






- Rotate the crankshaft opposite the engine rotation direction - arrow direction 2 - and secure the tensioner using a locking pin (T40011).

• The intake camshaft switches in the engine rotation direction.

- Remove the guide pin - 1 - and guide the tensioning rail - 2 - downward.






- Remove the upper guide rail - 3 - by unlocking the latch with a screwdriver and pushing the guide rail forward.

• When the lower timing chain cover is installed, the loose chain on the crankshaft cannot jump off.

- Remove the camshaft timing chain from the sprockets.


Danger of damaging the valves, piston head and lower timing chain cover.

• If the camshaft timing chain was removed from the cylinder head, then the crankshaft must not be rotated further.

• Panels are installed on the lower timing chain cover to prevent the chain from falling down. The panels can bend if the crankshaft is rotated when the chain is loose.

- Remove the ignition coils with output stages, refer to => [ Ignition Coil with Power Output Stage ] Service and Repair, and lay the wiring harness to the side.






- Disconnect the hose - 1 - from the crankcase ventilation.

- Remove the bolts - arrows -.

- Remove the charge air pipe bolt - arrow -.






- Loosen the hose clamp - 2 - and remove the charge air pipe together with the crankcase ventilation.






- Disconnect the vacuum line - 1 - and free up the wire.

- Disconnect the connector from the camshaft position sensor (G40) - 2 -.

- Remove the cylinder head cover bolts in sequence - 1 through 6 -.






- Remove the cylinder head cover.

- Remove the camshafts.

- Prevent dirt and adhesive residue from entering the cylinder head.

Installing

• Tightening specifications, refer to => [ Valvetrain Overview ] Service and Repair.

• The sealing surfaces must be completely free of oil and grease.

• The pistons must not be positioned at TDC.

• Make sure that all roller rocket arms make contact correctly on the valve stem ends.

• Note the expiration date of the silicone sealant.

• The cylinder head cover must be installed within 5 minutes after applying the silicone sealant.

- Remove any sealant residue on the cylinder head using a flat blade scraper.


Risk of eye injury.

• Wear protective eyewear.

• Prevent dirt and adhesive residue from entering the cylinder head.

- Remove any sealant out of the groove in the cylinder head cover as well as from any sealing surface using, for example, a rotating plastic brush.






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

- Cut the sealant tube nozzle at the front mark (nozzle diameter: approximately 2 mm).






- Lubricate the running surfaces of both camshafts.

- Place the camshafts into the cylinder head; the recesses - arrows - must be perpendicular to each other.






- Replace the cylinder head cover bolts.

- Apply the silicone sealant to the clean sealing surface of the cylinder head cover as shown - arrows -.






• Thickness of sealant bead: 2 to 3 mm.

• The cylinder head cover must be installed within 5 minutes after applying the silicone sealant.

• The sealant bead may not be thicker than specified, otherwise the excess sealant could enter the oil pan and clog the oil intake tube.

• Note the expiration date of the sealant.

- Tighten the bolts in several steps:

• Tightening sequence and specification, refer to => [ Cylinder Head Cover Bolt Tightening Sequence and Specification ] Service and Repair.

• Make sure the cylinder head cover is not tilted.

- Insert the cap - 1 - without sealant using the thrust piece (T10174) :






• Dimension - a - = 1 to 2 mm.


When rotating the crankshaft, make sure the timing chain cannot damage any other components.

- Use the counter hold tool (T10355) to rotate the vibration damper to TDC - arrow -:






• The notch on the vibration damper must line up with the arrow mark on the lower timing chain cover.

• The marked links on the timing chain must be positioned on the marks on the chain sprockets.

- Install the camshaft timing chain:






• The marked drive chain/sprockets - arrows - must align.

- Turn the intake camshaft using the wrench in the - direction of the arrow - and install the timing chain.

Further installation is in the reverse order of removal.