Camshaft Timing Chain

Camshaft Timing Chain

Special tools, testers and auxiliary items required

• Camshaft Bar (T10068 A)

• Sealant

Removing the camshaft timing chain

• Engine installed.

- Drain coolant. Refer to => [ Cooling System, Draining and Filling ] Service and Repair.

- Remove intake manifold.

- Remove coolant thermostat housing. Refer to => [ Coolant Thermostat Housing ] Coolant Thermostat Housing.

Vehicles with engine code BUB:

- Remove the hose - 2 - from the secondary air injection (AIR) combination valve.





• Ignore - 1 -.

Vehicles with engine code CBRA:

- Disconnect the hose - 1 - and the vacuum hose - 2 - from the left Secondary Air Injection (AIR) combination valve.





• Ignore - 3 - and - arrows -.

All Vehicles

- Mark and disconnect electrical connectors:





1. Camshaft Adjustment Valve 1 (exhaust) (N318)

2. Camshaft Adjustment Valve 1 (N205)

3. Camshaft position sensor (G40)

4. Camshaft position (CMP) sensor 2 (G163)

- Remove Ground (GND) wire - 5 -.

- Disconnect coolant hose - 6 -.

- Remove electrical wiring bracket - arrows -.

- Place bracket with electrical wiring toward front.

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

- Adjust crankshaft at vibration damper bolt in direction of engine rotation to "TDC" marking - arrow -.





- Cams - A - of cylinder 1 must face each other.





- At the same time, (T10068 A) must engage in both shaft grooves. Turn crankshaft 1 additional turn if necessary.





- Remove camshaft timing chain tensioner - arrow -.





- Remove the bolts - 1, 2 and 3 -.





The cylinder head seal could be damaged.

• Remove upper timing chain cover horizontally from cylinder head.

- Remove bolts - arrows - and remove guide rail - 1 -.





- Remove (T10068 A).

• (T10068 A) must not be inserted when loosening or tightening camshaft adjuster bolts.

- Remove intake side camshaft adjuster bolt by counter-holding on camshaft hex head with open-end spanner.





- Remove intake-side camshaft adjuster.

- Remove exhaust side camshaft adjuster bolt by counter-holding on camshaft hex head with open-end spanner.





- Remove exhaust-side camshaft adjuster.

- Place camshaft timing chain over camshaft adjustment valves.

Installing (Adjusting valve timing)





• Tightening specifications, refer to => [ Timing Chain Covers Assembly Overview ] Service and Repair, => [ Upper Timing Chain Cover - Tightening Specifications
and Tightening Sequence ] Service and Repair and => [ Timing Chain Component Overview ] Timing Chain Component Overview.

- Insert guide rail - 1 - and tighten - arrows -.

- Check again if crankshaft is at "TDC" marking - arrow -.





- Verify camshaft TDC position:

• Cams - A - of cylinder 1 must face each other.





• It must be possible to insert camshaft bar (T10068 A) into both shaft grooves.





- If necessary, turn camshafts at hex head surfaces - arrows - to correct position using open end wrench SW 32.





Risk of damaging valves and piston crowns.

• If camshafts are rotated, crankshaft may not rest with any piston at "TDC".

- If necessary, rotate camshaft at hex head - arrows - with open-end spanner into correct position.







• Both camshaft adjusters (identification: 24E on intake side and 32A on exhaust side) can only be bolted in one position on the camshaft mountings - arrows - by an alignment pin.

- First install intake side camshaft adjuster:





- Rotate sensor wheel - 1 - clockwise in camshaft adjuster as far as stop - arrow -.

- Hand tighten intake side camshaft adjuster in this position to intake camshaft.





• Contact surface of sensor wheel at bolt head must be dry when installing.

• The "24E" marking - 1 - and the tooth behind it must align with notch - 2 - in control housing. Markings on control housing => [ Markings on Control Housing with MPI Engines ] Timing Chain Component Overview.

- Lay camshaft timing chain in this position tightly against intake side camshaft adjuster sprocket.

- Starting with the toothed that has the "24E" marking, count exactly 16 rollers to the right on the timing chain. Mark this roller with a color marker.





• Exhaust camshaft adjuster is locked in the rest state. Therefore the sensor wheel cannot be rotated when adjusting the valve timing. If locking mechanism in rest state is not engaged (locked) turn adjuster in both directions by hand until it locks. If that is not possible, replaced camshaft adjuster.

- Now insert exhaust camshaft adjuster "32A" with tooth at arrow marking - 1 - into camshaft roller chain so that the exact, previously counted 16 rollers lie between marking "24E" and "32A" and markings - 1 - and - 2 - align.





- Exhaust camshaft adjuster must be able to be inserted easily on exhaust camshaft and be tightened hand-tight.

- Check the position of both camshaft adjusters one more time for correct adjustment.





- Remove (T10068 A).





- Tighten bolt on camshaft adjuster intake side by counter-holding with open-end spanner on camshaft hex head.

- Tighten bolt on camshaft adjuster exhaust side by counter-holding with open-end wrench on camshaft hex head.





Risk of timing chain jumping off.

• If the crankshaft is rotated, forcefully press camshaft tensioning rail by hand (instead of with chain tensioner) against camshaft adjuster timing chain - arrow -.







- Rotate crankshaft 2 revolutions in direction of engine rotation at vibration damper bolt and place at "TDC" marking - arrow -.





• At the same time, the (T10068 A) must engage in both shaft grooves.





- If camshaft bar cannot be engaged, adjust timing again.

- Clean sealant residue from 3 mm bores - arrows - in cylinder head seal.





• With cylinder head installed, holes in cylinder head seal are only half visible.

- Fill 3 mm bores in cylinder head seal with sealant.

- Replace timing chain upper cover sealing ring. Refer to=> [ Timing Chain Upper Cover Seal ] Timing Chain Upper Cover Seal.

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

- Check whether fitting sleeves - 2 - and - 3 - are inserted in upper timing chain cover.





- Insert new sealing ring - 1 - and new seal - 4 -.

- Lightly coat clean sealing surface - shaded - on timing chain upper cover with sealant.

- Coat sealing surface below cylinder head seal with some sealant. Do not bend cylinder head seal.

• Timing chain upper cover must be installed with 5 minutes of applying sealant.





- Position upper timing chain cover and tighten => [ Upper Timing Chain Cover - Tightening Specifications
and Tightening Sequence ] Service and Repair.

- Install camshaft timing chain tensioner - arrow -.





- Rotate crankshaft 2 revolutions in direction of engine rotation at vibration damper bolt and place at "TDC" marking.

- Check timing again.

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

- Install intake manifold.

- Install coolant thermostat housing. Refer to => [ Coolant Thermostat Housing ] Coolant Thermostat Housing.