Camshaft: Service and Repair

Camshafts and camshaft adjusters, removing and installing
Removing
- Remove toothed belt from camshaft sprockets. Service and Repair
- Remove camshaft sprockets from cylinder bank 5-8.





- Loosen bolts -1-.
- Remove bolts -2- and toothed belt cover.
- Remove cylinder head cover.
- Remove Camshaft Position (CMP).





- Check TDC position of camshafts:
Both markings on camshafts must align with arrows on bearing caps.

When re-using drive chain:





- Clean drive chain and camshaft sprockets. Mark position with paint.

CAUTION! DO NOT mark chain with punch or scriber, use paint only.

Continuation:





- Secure camshaft adjuster with bracket for chain tensioning tool 3366.

CAUTION!
- Do not over-tighten bracket for chain tensioning tool, otherwise camshaft adjuster may be damaged





- Regardless of how bearing caps are marked, mark sequence and installation position of all bearing caps as shown in illustration.





- Remove bolts for camshaft adjuster -arrow-.
- Remove bearing cap 0.
- Remove bearing caps 1, 3, 5, 7 and 8 and place in order on clean surface.
- Loosen bearing caps 2, 4, and 6 diagonally and remove.
- Remove camshafts with camshaft adjuster.

Installing:
- Install camshaft adjuster in reverse order of removal but note the following:
- Replace half-round cap.





- Replace rubber-metal gasket for camshaft adjuster and coat the hatched area lightly with sealer AMV 1 8802.

CAUTION! Part numbers are listed for reference only. Always check with your Parts department for latest information.

- Place drive chain on camshaft sprockets as follows:

When using the old chain:





- Align paint markings -arrows-.

When using a new drive chain:





- The distance between camshaft markings -A- and -B- must be 16 rollers of the drive chain. Position rollers 1 and 16 according to illustration.
- Chain rollers 1 and 16 are offset by 1/2 tooth width to the left in relation to markings -A- and -B-.
- Insert camshaft adjuster next to chain (requires second technician).
- Place camshafts with drive chain and camshaft adjuster into cylinder head.
- Lubricate running surfaces of camshafts with oil.

Note: Be sure locating dowels for bearing caps and camshaft adjuster, are installed in cylinder head.





- Tighten camshaft adjuster (observe locating dowels).
- Install bearing caps 3, 5, and 7 according to markings.
- Tighten bearing caps 3, 5, and 7 of intake and exhaust camshafts diagonally (observe locating dowels).
- Install remaining bearing caps of intake and exhaust camshafts and tighten them from inside to outside in alternating diagonal sequence.
- Tighten camshaft adjuster -10- (pay attention to alignment bushings).
- Remove bracket for chain tensioner 3366.
- Check camshafts for correct adjustment.





Alldata Editor NOTE:
Always check camshafts for correct final alignment as per instructions below.

- Both markings at camshafts must align with markings on bearing caps -arrows-.

Note: To make sure that alignment is correct, turn camshaft in direction of engine operation.





- Coat gray area of double bearing cap -5 and outer bearing cap -0- next to camshaft adjuster lightly with sealer AMV 18802. Install bearing cap with camshaft seals (observe locating dowels).
Install remaining bearing caps (observe locating dowels).

CAUTION! Part numbers are listed for reference only. Always check with your Parts department for latest information.

- Tighten remaining bearing caps.
- Install toothed belt (adjust timing).

Note: Observe all notes regarding removing and installing toothed belt, Refer to Engine; Service and Repair.

- Install cylinder head cover, Refer to Cylinder Head.

Note:
- DO NOT immediately start engine after installing camshafts. Wait for at least 30 minutes, otherwise valves may hit pistons. The hydraulic lifters have to settle first.
- After work on the valve train, carefully turn crankshaft by hand for two revolutions to be sure that no valve contacts a piston.

Tightening torques
Bearing Cap To Cylinder Head 10 Nm + 90 degrees (7 ft. lbs. + 90 degrees)
Camshaft Adjuster To Cylinder Head 10 Nm + 90 degrees (7 ft. lbs. + 90 degrees)
Camshaft Position (CMP) Sensor Rotor To Camshaft 23 Nm (17 ft. lbs.)
Camshaft Position (CMP) Sensor Housing To Cylinder Head 10 Nm (7 ft. lbs.)