gas type FORD SIERRA 1985 1.G DOHC Engine Workshop Manual

Torque wrench settingsNmlbf ft
Main bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90 to 10466 to 77
Connecting rod (big-end bearing cap) bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 to 84 to 6
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 to 1711 to 13
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle-tighten a further 85º
Crankshaft pulley bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45 to 5833 to 43
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle-tighten a further 80º
Camshaft sprocket bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 to 6341 to 46
Flywheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82 to 9261 to 68
Oil pump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 to 127 to 9
Oil pump sprocket bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 to 1912 to 14
Oil pump chain tensioner bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 to 137 to 10
Sump bolts and nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 to 106 to 7
Sump studs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 to 84 to 6
Sump drain plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 to 2815 to 21
Sump front mounting plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 to 2817 to 21
Oil baffle nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 to 2113 to 15
Oil pick-up pipe-to-cylinder block bolts . . . . . . . . . . . . . . . . . . . . . . . . .9 to 137 to 10
Oil pressure warning lamp switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 to 2213 to 16
Cylinder head bolts:
M11 bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4030
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5541
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle-tighten a further 90º
Stage 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle-tighten a further 90º
M8 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 to 3927 to 29
Camshaft cover bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 to 84 to 6
Camshaft bearing cap nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 to 2616 to 19
Lower timing chain guide upper bolt . . . . . . . . . . . . . . . . . . . . . . . . . . .10 to 137 to 10
Lower timing chain guide lower bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 to 2818 to 21
Upper and lower timing chain cover bolts . . . . . . . . . . . . . . . . . . . . . . .7 to 105 to 7
Crankshaft rear oil seal housing bolts . . . . . . . . . . . . . . . . . . . . . . . . . .8 to 116 to 8
Engine-to-gearbox/transmission bolts . . . . . . . . . . . . . . . . . . . . . . . . . .29 to 4121 to 30
The 2.0 litre DOHC (Double OverHead
Camshaft) engine was introduced in August
1989 to replace the 2.0 litre SOHC engine
used previously in the Sierra range. The
engine is of four-cylinder, in-line type.
The crankshaft incorporates five main
bearings. Thrustwashers are fitted to the
centre main bearing in order to control
crankshaft endfloat.
The camshafts are driven by a chain from
the crankshaft, and operate the angled valves
via hydraulic cam followers. One camshaft
operates the inlet valves, and the other
operates the exhaust valves. The operation of
the cam followers is explained in Chapter 2,
Part C, but note that no rollers are fitted and
the base of each cam follower is in direct
contact with the cam profile.
The distributor is driven directly from the
front of the inlet camshaft, and the oil pump is
driven by a chain from the crankshaft. An
electric fuel pump is mounted in the fuel tank.Lubrication is by means of a bi-rotor pump
which draws oil through a strainer located
inside the sump, and forces it through a full-
flow filter into the engine oil galleries, from
where it is distributed to the crankshaft and
camshafts. The big-end bearings are supplied
with oil via internal drillings in the crankshaft.
The undersides of the pistons are supplied
with oil from drillings in the connecting rods.
The hydraulic cam followers are supplied with
oil from passages in the cylinder head. The
camshafts are lubricated by oil from spray
tubes mounted above the camshaft bearing
caps.
A closed crankcase ventilation system is
employed, whereby piston blow-by gases are
drawn from the crankcase, through a breather
pipe into the inlet manifold, where they are
burnt with fresh air/fuel mixture.
Refer to Chapter 1, Section 35.The following operations can be carried out
without removing the engine from the vehicle:
a)Removal of the camshafts.
b)Removal and servicing of the cylinder head
c)Removal of the timing chain and
sprockets.
d)Removal of the oil pump.
e)Removal of the sump.
f)Removal of the pistons and connecting
rods.
g)Removal of the big-end bearings.
h)Removal of the engine mountings
i)Removal of the clutch and flywheel.
j)Removal of the crankshaft front and rear
oil seals.
The following operation can only be carried out
after removing the engine from the vehicle:
a)Removal of the crankshaft and main
bearings.
4Major operations requiring
engine removal
3Major operations possible with
the engine in the vehicle
2Crankcase ventilation system -
inspection and maintenance
1General information
DOHC engine 2B•3
2B

Dismantling
1Refer to Chapter 2, PartA, Section 18,
paragraphs 1 to 8 inclusive.
2A suitable selection of splined and Torx
sockets will be required to remove many of
the bolts when dismantling the engine.
3Before dismantling the main engine
components, the following externally-
mounted ancillary components can be
removed, with reference to the relevant
Chapters of this Manual and the relevant
Sections of this Chapter, where applicable.
Inlet manifold (and carburettor, if applicable)
Exhaust manifold
Alternator.
Coolant pump, and thermostat
Alternator/coolant pump drivebelt tensioner
Distributor cap, HT leads and spark plugs
Oil pressure warning lamp switch
Crankshaft speed/position sensor
Oil filter
Dipstick
Engine mounting brackets (if not already done)
Crankcase ventilation pipe and hoses
Clutch
Alternator mounting bracket.
Air conditioning compressor mounting
bracket (where applicable).
Engine lifting brackets.
Examination and renovation
4Refer to Chapter 2, PartA, Section 18, but
note that the connecting rod bolts should be
renewed on reassembly, and when renewing
the cylinder head bolts, the latest type bolts
with hexagonal heads should always be used.
Reassembly
5Proceed as described in Chapter 2, PartA,
Section 18, noting the following:
6If they have been removed, new cylinder
head bolts (both M11 and M8, of the latest
type with hexagonal heads), flywheel bolts,
and connecting rod bolts must be used.
Note: Refer to the warning at the beginning of
Section 5 before proceeding. A suitable puller
will be required to remove the crankshaft pulley.
A new crankshaft pulley bolt, a new timing chain
tensioner plunger assembly, new upper and
lower timing chain cover gaskets, and a new
camshaft cover gasket and reinforcing sleeve
sealing rings, must be used on refitting.
Removal
1If the engine is in the car, carry out the
following operations:
a)Disconnect the battery negative lead.
b)To improve access, remove the radiator. It
will be difficult to remove the crankshaft
pulley with the radiator in place.c)On carburettor models, remove the air
cleaner.
d)On fuel injection models, remove the air
inlet hose, plenum chamber, and air
cleaner lid as an assembly.
e)Disconnect the breather hose from the
camshaft cover.
f)Remove the distributor cap and HT leads,
and the rotor arm and housing.
2Proceed as described in paragraphs 2 to 11
inclusive of Section 18 (see illustration).
3Remove the alternator drivebelt.
4Slacken the crankshaft pulley bolt. Prevent
the crankshaft from turning by engaging top
gear (manual gearbox only) and having an
assistant press the brake pedal hard, or by
removing the starter motor and jamming the
ring gear teeth with a lever.
5Unscrew the bolt part-way, and use a puller
to remove the crankshaft pulley. The legs ofthe puller must be suitably shaped to enable
them to rest on the metal surfaces of the
pulley. Do not use a puller on the rubber
surface of the pulley (see illustrations).
15Timing chain and sprockets -
removal and refitting
14Engine dismantling,
examination, renovation and
reassembly - general information
2B•8DOHC engine
15.2 Timing chain, oil pump drive chain and associated components
1 Upper timing chain guide
2 Exhaust camshaft sprocket
3 Timing chain
4 Lower timing chain guide
5 Crankshaft sprocket (double)
6 Crankshaft
7 Oil pump chain tensioner
8 Oil pump drive chain
9 Oil pump10 Oil pressure relief valve
11 Oil passage to timing chain tensioner
plunger
12 Plug
13 Timing chain tensioner plunger
14 Timing chain tensioner sprocket
15 Timing chain tensioner arm
16 Inlet camshaft sprocket
17 Copper chain links
15.5a Remove the crankshaft pulley using
a puller (viewed from under vehicle)

6Loosen the alternator lower mounting
through-bolt, then remove the alternator
upper mounting bolt, and swing the alternator
away from the engine.
7Unscrew the central securing bolt, and
withdraw the drivebelt tensioner assembly.
8Unscrew the eleven securing bolts, and
remove the lower timing chain cover. Recover
the rubber gasket.
9Using a suitable Torx socket, unscrew the
securing screw, and carefully withdraw the oil
pump chain tensioner (see illustration).
10Unscrew the Torx type securing bolt, and
withdraw the oil pump sprocket, complete
with the oil pump drive chain.
11Unscrew the two lower timing chain guide
securing bolts, noting their locations, and
withdraw the timing chain guide through the
top of the timing case (see illustration).
12Remove the Woodruff key from the end of
the crankshaft, prising it free with a
screwdriver if necessary, then slide the double
chain sprocket from the end of the crankshaft,
and lift the chain from the sprocket (see
illustration).
13Withdraw the timing chain through the top
of the timing case and, where applicable,
remove the cable-tie from the chain (see
illustration).
Refitting
14Commence refitting as follows. Note that
coppered links are provided in the timing
chain to assist with refitting, but these can be
difficult to see on a chain which has already
been in service. If possible, position thecoppered links as described during the
following procedure. If the coppered links are
not visible, the chain should still be refitted as
described, but ignore the references to the
coppered links.
15Make sure that the slot for the Woodruff
key in the end of the crankshaft is pointing
vertically downwards. If necessary,
temporarily refit the crankshaft pulley bolt in
order to turn the crankshaft to the required
position.
16Lower the timing chain into the timing
case from above, with the single coppered
link at the bottom. If desired, use a cable-tie
to prevent the chain from dropping into the
timing case, as during removal.
17Locate the double chain sprocket loosely
over the end of the crankshaft (larger sprocket
nearest the crankcase), with the timing mark
pointing vertically down.
18Fit the chain over the inner, larger
sprocket, aligning the coppered link in the
chain with the timing mark on the sprocket
(see illustration).
19Coat the threads of the lower timing chain
guide lower securing bolt with a suitable
thread-locking compound.
20Introduce the lower timing chain guide
through the top of the timing case,
manipulating the chain around the guide as
necessary, then fit the chain guide lower
securing bolt and tighten it finger-tight.
21Push the double chain sprocket onto the
crankshaft, engaging the notch in the
sprocket with the groove in the end of the
crankshaft.22Proceed as shown in paragraphs 34 to 42
of Section 18 but when fitting the chain over
the camshaft sprockets, align the timing mark
on each sprocket between the two
corresponding coppered links in the chain.
23Coat the threads of the lower timing chain
guide upper securing bolt with a suitable
thread-locking compound, then fit the bolt
and tighten it finger-tight.
24Proceed as shown in paragraphs 43 to 46
of Section 18.
25Tighten the two chain guide securing
bolts to the specified torque.
26Proceed as shown in paragraphs 47 to 55
of Section 18.
27Fit the oil pump drive chain around the
outer crankshaft sprocket and the oil pump
sprocket, then refit the oil pump sprocket, and
tighten the securing bolt to the specified
torque. If necessary, a screwdriver can be
inserted through one of the holes in the
sprocket to prevent it from turning as the
securing bolt is tightened.
28Refit the oil pump drive chain tensioner,
and tighten the securing bolt to the specified
torque.
29Refit the Woodruff key to the end of the
crankshaft.
30Inspect the oil seal in the lower 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. The new seal
DOHC engine 2B•9
2B
15.11 Withdrawing the lower timing chain
guide
15.18 Coppered link in timing chain aligned
with crankshaft sprocket timing mark
(arrowed)15.13 Withdrawing the timing chain
through the top of the timing case
15.9 Oil pump chain tensioner securing
screw (arrowed)15.5b Position the legs of the puller on the
metal surfaces of the pulley (A), not the
rubber surface (B)
15.12 Sliding the double chain sprocket
from the end of the crankshaft