Timing Belt: Service and Repair
Toothed Belt
Special tools, testers and auxiliary items required
• Spanner Wrench (3212)
• Pin Wrench (3387)
• Locking Pin (T40011)
• Locking Pin (T40026)
• Socket (T40028)
• Camshaft Adjuster Gauge (T40030)
• Ignition Coil Puller (T40039)
Removing
- Bring the lock carrier into service position. Refer to => [ Lock Carrier, Moving into Service Position ] Lock Carrier, Moving Into Service Position.
- Remove ribbed belt tensioner. Refer to => [ Ribbed Belt Tensioner ] Ribbed Belt Tensioner.
- Remove power steering pump belt pulley - arrows - using Pin Wrench (3387) to counterhold.
- Remove 8 bolts - 1 -.
- Remove vibration damper - 2 - and, if equipped, thrust washer - 3 -.
• Thrust washer - 3 - is only equipped with toothed belt gear (06C 105 063 A). Thrust washer must not be installed with toothed belt gear (06C 105 063 B).
- Remove bolts - 1 to 12 - and remove left front, right front and lower toothed belt guards.
- Pull rear engine cover off - arrows -.
- Remove coolant expansion tank - arrow -.
- Disconnect electrical connection from Engine Coolant Level (ECL) Warning Switch (F66) at bottom of coolant reservoir and set aside coolant reservoir with coolant hoses - 1 to 3 - connected.
- Remove air filter housing - arrows -.
- Disconnect electrical harness connector - 1 - at Mass Air Flow (MAF) Sensor (G70).
- Disconnect air duct hose - 2 - together with Mass Air Flow (MAF) Sensor (G70).
- Remove the bolts - 1 - and - 3 -.
- Disconnect hose - 4 - to Secondary Air Injection (AIR) system pipe.
- Remove oil dipstick guide tube - 2 - upward out of upper part of oil pan and swivel forward.
- Remove screws - 5 - and - 6 - on right cylinder head cover.
- Disconnect electrical harness connectors - 1 to 4 -.
- Remove ignition coils - arrows - using Ignition Coil Puller (T40039).
- Disconnect crankshaft housing ventilation hose - arrow -.
- Remove bolts for right cylinder head cover in the sequence - 12 to 1 -.
- Remove cylinder head cover.
- Remove bolts - 4 - and - 5 - on left cylinder head cover.
- Disconnect electrical harness connectors - 1 to 3 - and - 6 -.
- Remove ignition coils - arrows - using Ignition Coil Puller (T40039).
- Disconnect crankshaft housing ventilation hose - arrow -.
- Remove bolts for left cylinder head cover in the sequence - 12 - 1 -.
- Remove cylinder head cover.
CAUTION!
Only turn over the engine at the crankshaft in direction of engine rotation (clockwise).
- Turn engine until cam lobes - arrows - to cylinder 3 (right cylinder bank) intake and exhaust camshafts face upward evenly.
• Turning over the engine is performed at the central bolt of the crankshaft.
- Insert Camshaft Adjuster Gauge (T40030) into right cylinder head camshafts.
• Turn crankshaft back and forth slightly so that Camshaft Adjuster Gauge (T40030) claws can engage on camshafts correctly.
- Spread Camshaft Adjuster Gauge (T40030) with threaded rods (specified torque max. 10 Nm) until it is seated with no play.
- Insert Camshaft Adjuster Gauge (T40030) in the same way in left cylinder head.
- If equipped, disconnect electrical connector to After-Run Coolant Pump (V51).
- Remove TDC mark sealing plugs from cylinder blocks.
- Install Locking Pin ( T40026) into hole, if necessary rotate crankshaft very slightly back and forth to completely center the pin.
• Catch escaping oil with a cloth.
- Pry circlips - 1 - for cover caps - 2 - using a screwdriver - 3 - at all camshaft gears.
- Loosen but do not remove bolts - 1 to 4 -.
• The bolts remain loose but screwed in.
- Turn toothed belt tensioning roller using 8 mm hex socket in direction of - arrow - until tensioning element on tensioning lever is pushed together enough that Locking Pin (T40011) can be inserted in piston and housing holes.
• The toothed belt tensioner is oil-dampened. Compress it by slowly applying constant pressure.
• Before removing toothed belt, mark the turning direction on it with chalk or a felt tip pen. A reversed turning direction can cause damage to the used toothed belt.
- Remove eccentric roller screw - arrow -.
- Remove toothed belt.
Installing (Adjusting valve timing)
• Camshafts locked using Camshaft Adjuster Gauge ( T40030).
• Crankshaft secured using Locking Pin (T40026).
• Camshaft gears loosened.
• Replace seals, sealing rings, O-rings and self-locking bolts.
• When turning camshaft, crankshaft must not be at TDC with any cylinder. Valves and/or pistons may be damaged.
- Screw on camshaft gears - 1 to 4 - until they can just still be turned and do not tilt.
- Place toothed belt as shown in illustration.
• Toothed belt and all toothed belt gears must fit exactly on front edge for a precise valve timing adjustment.
- Turn eccentric roller - 1 - using Pin Wrench (3387) clockwise until spanner wrench handle lies directly over coolant pump sprocket center axis - 2 -.
- Hold Pin Wrench (3387) securely in this position and tighten screw - 3 - to 45 Nm.
- Place torque wrench horizontally on tensioning lever hex socket.
- Turn toothed belt to 45 Nm in direction of - arrow - to pre-tension.
- Rotate toothed belt tensioning roller using 8mm hex socket in direction of - arrow - until Locking Pin (T40011) can be removed.
- Place torque wrench horizontally on tensioning lever hex socket.
- Turn toothed belt to 25 Nm in direction of - arrow - to tension.
- Place Socket (T40028) on exhaust camshaft adjuster on left cylinder bank.
- Rotate camshaft adjuster rotor clockwise to 10 Nm to stop - arrow -.
- Rotate camshaft adjuster rotor on right cylinder bank clockwise to 10 Nm to stop - arrow -.
- Tighten bolts for all four camshaft gears to 100 Nm.
- Insert cover caps - 2 - with new O-rings - 1 - on camshaft gears and secure with circlip.
• Ignore - 3 -.
- Remove Camshaft Adjuster Gauge (T40030).
- Remove crankshaft holder (T10026) and install TDC mark sealing plugs with new O-ring in cylinder block.
The rest of the installation is performed in reverse order of removal, noting the following:
- Install cylinder head covers. Refer to: Left => [ Left Cylinder Head Cover ] Left Cylinder Head Cover, right => [ Right Cylinder Head Cover ] Right Cylinder Head Cover.
- Install toothed belt covers. Refer to => [ Toothed Belt Covers Component Overview ] Service and Repair.
- Install vibration damper. Refer to => [ Vibration Damper ] Vibration Damper.
- Install ribbed belt tensioner. Refer to => [ Ribbed Belt Tensioner ] Ribbed Belt Tensioner.
- Install ribbed belt. Refer to => [ Ribbed Belt ] Ribbed Belt.
- Install the lock carrier with attachments. Refer to =>
Radiator Support Radiator Support
- Install the front bumper cover.
Tightening Specifications
