Camshaft: Service and Repair
Camshafts
Special tools, testers and auxiliary items required
• Impact Puller (T10133/3) from Tool Set (T10133)
• Locating Pins (T40116)
• Locking Pin (T40069)
• Camshaft Clamp (T40133)
• Hand drill with plastic brush attachment
• Protective goggles
• Sealant, refer to the Parts Catalog
• Here, removal and installation at left cylinder head is depicted in the following description.
Removing
- Remove the camshaft timing chains from the camshafts. Refer to => [ Camshaft Timing Chains ] Camshaft Timing Chains.
- To remove the camshafts in the left cylinder head, remove the vacuum pump.
- To remove the camshafts in the right cylinder head, remove the high pressure pump and pump motor housing.
- Remove the bolt - arrow - and remove the camshaft adjustment valve (N205) / (N208).
- Disconnect the connector - 1 - from the Camshaft Position (CMP) sensor (G40) / (G163).
• Ignore - arrow -.
- Remove the Ground (GND) wire bolt - 2 -.
• Ignore - 1 -.
- Free up the vacuum hose - 1 - on cylinder bank 2 (left).
- Remove the bolts - arrows - and remove the cover - 2 -.
- Loosen the guide frame bolts in the following sequence: - 21 to 1 -.
• Proceed in the same way with the right guide frame.
- Remove the bolts, carefully loosen the guide from out of the bond and place it with the camshafts on a soft surface.
- Remove the (T40133) - arrows -.
- Mark the camshafts, remove them and lay them on a clean surface.
Installing
• For the correct tightening specifications, refer to => [ Valvetrain Overview ] Valvetrain Overview.
• Replace the seals and sealing plugs.
• Secure crankshaft - 1 - in Top Dead Center (TDC) position using (T40069) in TDC.
• The hydraulic adjusting elements and roller rocker lever are inserted.
Risk of contaminating lubricating system and bearing.
• Cover open parts of the engine.
Danger of eye injury.
• Wear protective goggles.
- Remove the sealant residue on the cylinder head and guide frame and the upper section of the oil pan, for example using a rotating plastic brush.
- Clean the sealing surfaces; they must be free of oil and grease.
- Check the screen - arrow - for dirt; clean it if necessary.
- Oil running surfaces of both camshafts.
- Insert the camshafts in the guide frame.
• The placement of the camshafts must be exactly within the axial bearings - arrows - of the guide frame.
• The compression ring ends - 1, 2 and 3 - must face up or down. They must never face sideways.
- Rotate the guide frame with the camshafts inserted while holding them securely in the frame.
- Rotate the camshafts until the threaded holes - arrows - face upward.
- Check if the camshafts still lie in the guide frame axial bearings.
- Install the (T40133) in both cylinder heads and tighten - arrows - to 25 Nm.
• Note the expiration date of the sealing compound.
- Cut the tube nozzle at the front marking (nozzle diameter approximately 2 mm).
- Rotate the guide frame again.
Risk of contaminating camshaft bearing with excess sealant.
• Do not apply sealant beads thicker than indicated.
- Apply sealant beads - 4 through 8 - to the clean sealing surfaces on the guide frame as shown in the illustration.
• Thickness of sealant beads: 2.0 mm.
- Apply sealant beads - 1 through 3 - to the clean sealing surfaces on the guide frame as shown in the illustration.
• Thickness of sealant beads: 2.5 mm.
• The guide frame must be installed within 5 minutes after applying the sealant.
- Place the guide frame on the cylinder head.
- Insert the (T40116) in the guide frame and cylinder head.
- Tighten the camshaft guide frame bolts. Refer to => [ Camshaft Guide Frame Tightening Specifications and Sequence ] Valvetrain Overview.
• After installing the guide frame, let the sealant harden for approximately 30 minutes.
- Clean the hole in the cylinder head of any oil and grease.
- Coat the outer circumference of the sealing plug - arrow - with sealant; sealant, refer to the Parts Catalog.
- Drive in the sealing plugs until they are flush.
- Remove the (T40116) with the (T10133/3).
Install in reverse order of removal paying attention to the following:
- Install the camshaft adjustment valves (N205) / (N208). Refer to => [ Cylinder Head Overview ] Cylinder Head Overview.
- Install the high pressure pump motor housing and the high pressure pump.
- Install the vacuum pump.
- Position the camshaft timing chain on the camshafts. Refer to => [ Camshaft Timing Chains ] Camshaft Timing Chains.
Risk of damaging valves and piston heads after working on valve train.
• The motor must not be started for about 30 minutes after installing camshafts because the hydraulic equalization elements must seat themselves.
• To ensure valves do not strike pistons when starting, carefully rotate engine at least 2 full revolutions.