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4.3.
Adjusting camshaft timing
Once the procedure for checking camshaft timing has been carried out
and the camshaft timing has been found to be incorrect, it will be
necessary to adjust the timing.
Turn the engine over, in the normal direction of rotation, and return to a
position where the camshaft lobes on the inlet and exhaust camshafts
on 1st cylinder, face each other (Fig.8).
Fit the VS118/02 Flywheel Locking Pin and remove the Twin Vanos
Adjustment Unit as detailed in - 4.2 Removing and Replacing Twin
Vanos Adjustment Unit.
Depress the secondary chain tensioner and 'lock' down using
VS4311.02 Locking Pin from VS4425 Kit (Fig.9).
Remove the timing chain tensioner and fit VS4323 Pre-load Tool, but
DO NOT apply pre-load at this stage (Fig.10).
Release 3 screws ("A") by half a turn, then release 3 nuts ("B") by
two turns (Fig.11).
Release 3 nuts ("C") by one turn (Fig.12).
Carefully pull out the Toothed Sleeve (Inlet camshaft) until approx.
1mm of spline is visible (Fig.13).
Pull out Toothed Sleeve (Exhaust camshaft) to the 'stop' (Fig.14).
Fit the Camshaft Setting Plate Assembly at the rear of the camshafts,
ensuring it rests fully on the surface of the cylinder head (Fig.4).
Depress the secondary chain tensioner and remove VS4311.02
Locking Pin.
Pre-load the chain tensioner rail to 0.7Nm, using Pre-Load Tool
VS4323.
Pre-load cup spring on the exhaust sprocket by pressing it together
with the sensor gear and tighten the 3 nuts ("B") to finger-tight only
(Fig.15).
IMPORTANT: "Front" must be visible on Inlet sprocket
Remove the gasket and fit the VS4897 Twin Vanos Setting Tool
(without gasket fitted), and ensure Tool is in full contact with the
cylinder head. Fit and tighten bolts to secure (Fig.16).
Tighten 3 Screws ("A") on exhaust side to 5Nm (Fig.17).
Tighten 3 Nuts ("B") on exhaust side to 5Nm (Fig.18).
Tighten 3 Nuts ("C") on Inlet side to 5Nm (Fig.19).
Finally tighten 3 Screws ("A") and 6 Nuts ("B") and ("C") to specific
torque.
Remove the VS118/02 Flywheel Locking Pin and the Camshaft Setting
Plate Assembly.
Turn the engine over twice, in the normal direction of rotation, until the
camshaft lobes of the inlet and exhaust camshaft on 1st cylinder face
each other (Fig.4).
Re-fit the Flywheel Locking Pin and Camshaft Setting Plate Assembly,
ensuring that the Setting Plate rests fully on the surface of the cylinder
head.
Remove VS4323 Tensioner Pre-Load Tool and replace the chain
tensioner.
Remove all tools.
4.4.
Removing and Replacing front sprocket assembly to
remove/replace camshafts.
4.4.1. Removing
Remove the Twin Vanos Adjustment Unit as described earlier.
Remove timing chain tensioner. Depress the secondary chain
tensioner and lock with Pin VS4311.02 (from VS4425 kit).
Dismantle the front camshaft sprocket assemblies, ie. sensor gear,
plate springs, toothed sleeves and sprockets and sprocket chain.
Remove the secondary chain tensioner to achieve the dis-assembled
condition as shown in Fig.20.
NOTE: The timing chain should not be allowed to drop into the engine.
It can be suspended over the exhaust camshaft.
Remove the thrust washer and sensor gear off the Inlet camshaft.
WARNING: DO NOT release the screws (arrowed) at the ends of
the camshafts (Fig.20).
Fig.11
Fig.13
Fig.15
Fig.17
Fig.19
Fig.12
Fig.14
Fig.16
Fig.18
Fig.20
VS4895 - 1 - 210207
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