Removal and Replacement
Camshafts, removing and installing
Removing
Special tools, testers and auxiliary items required
^ Bracket for chain adjustment 3366
^ Torque wrench V.A.G 1331
^ Torque wrench V.A.G 1332
^ Sealant AMV 174 004 01
^ Sealant D 454 300 A2
Removing
- Perform work steps to remove toothed belt.
- Remove vibration damper/belt pulley.
- Remove toothed belt guard/belt pulley.
- Remove bracket for viscous fan clutch.
- Remove camshaft gears that have been loosened to remove toothed belt.
- Unscrew crankshaft holder 3242 and turn crankshaft 45° counter-clockwise so that no pistons are positioned at TDC.
- Remove rear toothed belt guard.
- Remove cylinder head cover.
- Remove camshaft position sensor housing.
- Unscrew sensor wheel for Camshaft Position (CMP) sensor. While doing this, carefully pry sensor wheel off camshaft.
- Clean drive chain and camshaft chain sprockets across from both - arrows - on bearing caps and mark installed position with a color marking.
Note:
^ Do not mark chain using punch, notch or similar.
^ The distance between both - arrows - or colored markings consists of 16 rollers of the drive chain.
- Next, secure crankshaft adjuster using bracket for chain adjustment 3366.
Note: The bracket for chain adjustment 3366 must not be tightened too much, otherwise the camshaft adjuster may be damaged.
- Independent of existing markings on bearing caps, mark sequence and installation position on all bearing caps, as shown in illustration.
- Remove bolts of camshaft adjuster - arrow -.
- Remove bearing cap - 0 -.
- Remove bearing caps - 1 -, - 3 -, and - 5 - and lay on a clean surface in correct order.
- Loosen bearing caps - 2 - and - 4 - of both camshafts, alternating in diagonal sequence.
- Lift out both camshafts together with camshaft adjuster.
Installing
Conditions
^ The pistons must not be positioned at TDC.
Work procedure
- Replace rubber/metal seal for camshaft adjuster and coat hatched surface with thin coat of sealant D 454 300 A2.
- Place drive chain onto camshaft chain sprockets as follows:
When using old drive chain
^ Move color markings - arrows - to aligned position.
When using a new drive chain
^ The distance between the notches - A - and - B - on the camshafts must consist of 16 rollers on the drive chain. Illustration shows where first and sixteenth drive chain rollers - arrows - must be installed on chain sprockets.
^ The chain rollers - 1 - and - 16 - are across from notches - A - and - B -, and are respectively a 1/2 tooth width offset to the left.
- Push camshaft adjuster in between drive chain.
- Oil journal surfaces of camshafts.
- Insert both camshafts together with camshaft adjuster.
Note: Alignment bushings for bearing caps and camshaft adjuster must be installed in cylinder head.
- Install bearing caps - 2 - and - 4 - for both camshafts according to markings.
- Intake camshaft: Casting marks point toward drive chain
- Exhaust camshaft: Casting marks point toward exhaust manifold side
- Fasten caps alternating diagonally and then tighten them to 10 Nm (pay attention to alignment pins).
- Install both bearing caps - 1 - on chain sprockets of intake and exhaust camshafts.
- Remove bracket for chain adjustment 3366.
- Check whether camshafts are correctly adjusted:
^ Both markings on camshafts must be aligned with both arrows on bearing caps - arrows -.
Note: So that both markings line up, turn camshaft slightly back or forth if necessary.
- Coat hatched surface of bearing cap - 0 - and of bearing cap - 5 - lightly with sealant AMV 174 004 01.
- Install bearing caps - 0 -, - 3 - and - 5 - and tighten to 10 Nm (pay attention to alignment pins).
- Tighten camshaft adjuster - arrow - to 10 Nm (pay attention to alignment pin).
- Using a small screwdriver, carefully apply a thin layer of sealant D 454 300 A2 to both edges of sealing surfaces between bearing cap and cylinder head - arrows -.
The rest of the assembly is basically a reverse of the disassembly sequence.
- Replace seal for intake and exhaust camshaft.
- Turn crankshaft 45° clockwise to set cyl. 3 to TDC again and secure it with crankshaft holder 3242.
- Install and tension toothed belt.
Note: After installing new valve lifters, do not start the engine for approx. 30 minutes. The hydraulic equalization elements must seat themselves (otherwise the valves will make contact with the pistons).