clock FORD SIERRA 1987 2.G DOHC Engine Workshop Manual

42Fit a new upper timing chain guide to the
plate at the front of the cylinder head.
43Turn the crankshaft clockwise until the
inlet camshaft begins to turn.
44If the chain tensioner plunger piston
protrudes from the cylinder, unlatch the piston
by pressing the chain tensioner arm down by
hand.
45If the plunger piston is below the top
surface of the cylinder, a tool similar to that
shown(see illustration)must be fabricated to
unlatch the piston. It is suggested that a 2.5
mm diameter welding rod is used to
manufacture the tool. Use the tool to release
the piston as follows.
46Carefully lift the chain tensioner arm with
a screwdriver, and insert the tool between the
tensioner arm and the piston. Remove the
screwdriver, and release the piston by
pressing the tensioner arm down by hand.
Carefully withdraw the tool once the piston
has been released.
47Tighten the camshaft sprocket securing
bolts to the specified torque, holding the
sprockets stationary as during removal.
48Turn the crankshaft clockwise through
two complete revolutions, and check that the
timing marks on the camshaft sprockets are
still aligned with the top face of the cylinder
head as described in paragraph 4.
49Turn the crankshaft clockwise through
another complete revolution, and check that
the timing marks on the camshaft sprockets
are facing each other, directly in line with the
top face of the cylinder head. 50If the timing marks do not align as
described, the timing chain has been
incorrectly fitted (probably one chain link
away from the correct position on one of the
camshaft sprockets), and the chain should be
removed from the sprockets and refitted
again in the correct position as described
previously.
51Inspect the oil seal in the upper timing
chain cover. If the oil seal is in good condition,
the cover can be refitted as follows, but if the
seal is damaged, or has been leaking, a new
seal should be fitted to the cover. If
necessary, carefully prise the old oil seal from
the cover using a screwdriver, and drive in the
new seal using a suitable metal tube. Make
sure that the seal lip faces into the engine.
Take care not to damage the timing chain
cover.
52Fit the upper timing chain cover using a
new rubber gasket. Great care must be taken
to avoid damage to the oil seal when passing
the seal over the end of the inlet camshaft.
Careful manipulation will be required (possibly
using a thin feeler blade) to avoid damage to
the oil seal sealing lip. Note that the oil seal
should be fitted dry.
53Refit the timing chain cover securing bolts
and studs in their original locations, and
tighten them to the specified torque (see
illustration).
54Remove the reinforcing sleeves from the
camshaft cover, and renew the rubber sealing
rings. Note that the four short reinforcing
sleeves fit at the front of the cover (see
illustration).
55Refit the camshaft cover using a new
gasket, and tighten the securing bolts and
studs to the specified torque.
Note: A valve spring compressor will be
required during this procedure. New valve
stem oil seals should be used on reassembly.
1Proceed as described in Chapter 2, PartC,
noting the following points:
a)Ignore the references to removing and
refitting the camshaft.
b)Double valve springs are used on all the
valves (see illustration).c)Ignore the reference to inlet valve
dampers.
d)Refer to the following Section if the
cylinder head is to be inspected and
renovated.
1Refer to Chapter 2, PartA, noting the
following points:
a)Valve and valve seat cutting and
regrinding can be carried out using
conventional tools.
b)The cylinder head cannot be resurfaced,
and if the surface distortion exceeds the
specified limits, the cylinder head must be
renewed.
Note: Once the timing chain has been
removed from the camshaft sprockets, do not
turn the crankshaft until the timing chain has
been correctly refitted - this is to prevent
contact between the valves and pistons. A
new timing chain tensioner plunger assembly,
a new upper timing chain cover gasket, and a
new camshaft cover gasket and reinforcing
sleeve sealing rings, must be used on refitting.
Removal
1If the engine is in the vehicle, carry out the
following operations:
a)Disconnect the battery negative lead.
b)On carburettor models, remove the air
cleaner.
c)On fuel injection models, remove the air
inlet hose, plenum chamber, and air
cleaner lid as an assembly.
d)Disconnect the breather hose from the
camshaft cover.
e)Remove the distributor cap and HT leads,
and the rotor arm and housing. If
necessary, mark the HT leads to aid
refitting.
2Proceed as described in paragraphs 2 to 15
inclusive of Section 18.
21Camshafts and cam
followers - removal, inspection
and refitting
20Cylinder head - inspection
and renovation
19Cylinder head - dismantling
and reassembly
2B•14DOHC engine
18.45 Fabricated tool used to unlatch
tensioner plunger piston
18.54 Fitting a camshaft cover reinforcing
sleeve and sealing ring
19.1 Withdrawing the double valve springs
from the cylinder head
18.53 Upper timing chain cover securing
stud locations (arrowed)