ESP FORD SIERRA 1988 2.G SOHC Engines Workshop Manual

Piston ring end gap:
Top:
Up to 1985 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.038 to 0.048 mm
From 1985 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.400 to 0.600 mm
Centre:
Up to 1985 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.038 to 0.048 mm
From 1985 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.400 to 0.600 mm
Bottom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.400 to 1.400 mm
Auxiliary shaft
Endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.050 to 0.204 mm (0.002 to 0.008 in)
Cylinder head
Specifications as for 1.3 litre engine
Valves
Specifications as for 1.3 litre engine except for the following:
Valve clearance (cold engine):
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.20 ±0.03 mm (0.008 ±0.001 in)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.25 ±0.003 mm (0.010 ±0.001 in)
Valve timing:All except code NAEEngine code NAE
Inlet opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24¼ BTDC18¼ BTDC
Inlet closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64¼ ABDC58¼ ABDC
Exhaust opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70¼ BBDC70¼ BBDC
Exhaust closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18¼ ATDC6¼ ATDC
Lubrication system
Specifications as for 1.3 litre engine
Torque wrench settingsNmlbf ft
Specifications as for 1.3 litre engine except for the following:
Crankshaft pulley bolt:
Fuel injection models up to 1987 . . . . . . . . . . . . . . . . . . . . . . . . . . . .115 to 13085 to 96
Fuel injection models from 1987 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 to 11574 to 85
SOHC engines 2A¥7
2A
The engine is of a four-cylinder, in-line,
single overhead camshaft type, mounted at
the front of the vehicle and available in 1.3,
1.6, 1.8 and 2.0 litre versions.
The crankshaft incorporates five main
bearings. Thrustwashers are fitted to the
centre main bearing in order to control
crankshaft endfloat.
The camshaft is driven by a toothed belt
and operates the slightly angled valves via
cam followers which pivot on ball-pins.
The auxiliary shaft which is also driven by
the toothed belt, drives the distributor, oil
pump and fuel pump.
The cylinder head is of crossflow design
with the inlet manifold mounted on the left-
hand side and the exhaust manifold mounted
on the right-hand side.
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 where it
is distributed to the crankshaft, camshaft and
auxiliary shaft. 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 big-ends.
The distributor shaft is intermittently supplied
with oil from the drilled auxiliary shaft. The
camshaft followers are supplied with oil via adrilled spray tube from the centre camshaft
bearing.
A semi-closed crankcase ventilation system
is employed whereby piston blow-by gases
are drawn into the inlet manifold via an oil
separator and control valve.
Refer to Chapter 1, Section 8.
Refer to Chapter 1, Section 23.
Refer to Chapter 1, Section 35.
1When engine performance is poor, or if
misfiring occurs which cannot be attributed to
the ignition or fuel system, a compression test
can provide diagnostic clues. If the test is
performed regularly it can give warning of
trouble before any other symptoms become
apparent.2The engine must be at operating
temperature, the battery must be fully
charged and the spark plugs must be
removed. The services of an assistant will also
be required.
3Disable the ignition system by
disconnecting the coil LT feed. Fit the
compression tester to No 1 spark plug hole.
(The type of tester which screws into the
spark plug hole is to be preferred.)
4Have the assistant hold the throttle wide
open and crank the engine on the starter.
Record the highest reading obtained on the
compression tester.
5Repeat the test on the remaining cylinders,
recording the pressure developed in each.
6Desired pressures are given in the
Specifications. If the pressure in any cylinder
is low, introduce a teaspoonful of clean
engine oil into the spark plug hole and repeat
the test.
7If the addition of oil temporarily improves
the compression pressure, this indicates that
bore, piston or piston ring wear was
responsible for the pressure loss. No
improvement suggests that leaking or burnt
valves, or a blown head gasket, may be to
blame.
8A low reading from the two adjacent
cylinders is almost certainly due to the head
gasket between them having blown.
9On completion of the test, refit the spark
plugs and reconnect the coil LT feed.
5Compression test
4Crankcase ventilation system -
inspection and maintenance
3Valve clearances - checking and
adjustment
2Engine oil and filter - renewal
1General information

Note: A valve spring compressor will be
required during this procedure. New valve
stem oil seals should be used on reassembly.
Dismantling
1With the cylinder head removed, remove
the camshaft.
2Using a valve spring compressor, compress
one of the valve springs until the split collets
can be removed from the groove in the valve
stem. Release the compressor and remove
the cap and spring, identifying them for
location. If the cap is difficult to release, do
not continue to tighten the compressor, but
gently tap the top of the tool with a hammer.
Always make sure that the compressor is
firmly located on the valve head and the cap.
Withdraw the valve (see illustrations).
3Repeat the procedure given in paragraph 2
for the remaining valves, keeping all
components identified for location so that
they can be refitted in their original positions.
4Prise the valve stem oil seals from the tops
of the valve guides (see illustration).
5Unscrew the cam follower ball-pins from
the cylinder head, keeping them identified for
location.
Reassembly
6Commence reassembly by refitting the cam
follower ball-pins to their original locations,
where applicable.
7Lubricate the valve stems and guides with
SAE 80/90 hypoid oil, then insert the valves
into their original guides.
8Wrap a thin layer of adhesive tape over the
collet groove of each valve, then smear the
new oil seals with a little SAE 80/90 hypoid oil
and slide them down the valve stems onto the
guides. If necessary use a suitable metal tube
to press the oil seals into the guides. Remove
the adhesive tape.
9Working on each valve in turn, fit the valve
spring and cap, then compress the spring
using the valve spring compressor and fit the
split collets to the groove in the valve stem.
Release the compressor and tap the end of
the valve stem with a soft-faced mallet tosettle the components. If the original
components are being refitted, ensure that
they are refitted in their original locations.
10Refit the camshaft.
Note: On engines fitted with hardened valve
seats for use with unleaded petrol, valve and
valve seat grinding and recutting cannot be
carried out without the use of specialist
equipment. Consult a Ford dealer for further
advice.
1This operation will normally only be
required at comparatively high mileages.
However, if persistent pre-ignition (ÒpinkingÓ)
occurs and performance has deteriorated
even though the engine adjustments are
correct, de-carbonizing and valve grinding
may be required.
2With the cylinder head removed, use a
scraper to remove the carbon from the
combustion chambers and ports. Remove all
traces of gasket from the cylinder head
surface, then wash it thoroughly with paraffin.
3Use a straight edge and feeler blade to
check that the cylinder head surface is not
distorted. If it is, it must be resurfaced by a
suitably equipped engineering works.
4If the engine is still in the vehicle, clean the
piston crowns and cylinder bore upper edges,
but make sure that no carbon drops between
the pistons and bores. To do this, locate two
of the pistons at the top of their bores and
seal off the remaining bores with paper andmasking tape. Press a little grease between
the two pistons and their bores to collect any
carbon dust; this can be wiped away when
the piston is lowered. To prevent carbon
build-up, polish the piston crown with metal
polish, but remove all traces of the polish
afterwards.
5Examine the heads of the valves for pitting
and burning, especially the exhaust valve
heads. Renew any valve which is badly burnt.
Examine the valve seats at the same time. If
the pitting is very slight, it can be removed by
grinding the valve heads and seats together
with coarse, then fine, grinding paste.
6Where excessive pitting has occurred, the
valve seats must be recut or renewed by a
suitably equipped engineering works.
7Valve grinding is carried out as follows.
Place the cylinder head upside down on a
bench on blocks of wood.
8Smear a trace of coarse carborundum
paste on the valve seat face and press a
suction grinding tool onto the valve head.
With a semi-rotary action, grind the valve
head to its seat, lifting the valve occasionally
to redistribute the grinding paste. When a dull
matt even surface is produced on the mating
surface of both the valve seat and the valve,
wipe off the paste and repeat the process with
fine carborundum paste as before. A light
spring placed under the valve head will greatly
ease this operation. When a smooth unbroken
ring of light grey matt finish is produced on
the mating surface of both the valve and seat,
the grinding operation is complete.
9Scrape away all carbon from the valve head
and stem, and clean away all traces of
grinding compound. Clean the valves and
seats with a paraffin soaked rag, then wipe
with a clean rag.
10If the guides are worn they will need
reboring for oversize valves or for fitting guide
inserts. The valve seats will also need
recutting to ensure that they are concentric
with the stems. This work should be entrusted
to a Ford dealer or local engineering works.
11Check that the free length of the valve
springs is as specified, and renew if
necessary. Do not renew individual springs; if
any springs are excessively worn, renew all
the springs as a set.
23Cylinder head - inspection
and renovation
22Cylinder head - dismantling
and reassembly
2A¥16SOHC engines
22.2a Compressing a valve spring22.2c Removing a valve
22.4 Removing a valve stem oil seal
22.2b Removing a valve spring and cap

4Mark the rotor faces so that the rotors can
be refitted in their original positions, then lift
the rotors from the pump body.
5Remove the pressure relief valve plug by
piercing it with a punch and levering it out,
then withdraw the spring and plunger.
6Thoroughly clean all parts in petrol or
paraffin and wipe dry using a non-fluffy rag.
Reassembly and inspection
7Commence reassembly by lubricating the
relief valve plunger. Fit the plunger and spring.
8Fit a new relief valve plug, flat side
outwards and seat it with a drift until it is flush
with the pick-up mating face.
9Lubricate the rotors and fit them. Note the
marks made when dismantling, if applicable.
10The necessary clearances may now be
checked using a machined straight edge (a
good steel rule) and a set of feelerblades. The
critical clearances are between the lobes of
the centre rotor and convex faces of the outer
rotor; between the outer and pump body; and
between both rotors and the end cover plate
(endfloat). The desired clearances are given in
the Specifications (see illustrations).
11Endfloat can be measured by placing a
straight edge across the pump body and
measuring the clearance between the two
rotors and the straight edge using feeler
blades (see illustration).
12New rotors are only available as a pair. If
the rotor-to-body clearance is excessive, a
complete new pump should be fitted.
13Refit the pump cover and tighten the
securing bolts.
14Fit the pick-up tube and strainer, using a
new gasket.
15Temporarily insert the driveshaft into the
pump and make sure that the rotors turn freely.16Prime the pump before refitting.
Removal
1Remove the sump and the cylinder head.
2Check the big-end bearing caps for
identification marks and if necessary use a
centre-punch to identify the caps and
corresponding connecting rods (see
illustration).
3Turn the crankshaft so that No 1 crankpin is
at its lowest point, then unscrew the nuts and
tap off the bearing cap. Keep the bearing
shells in the cap and connecting rod.
4Using the handle of a hammer, push the
piston and connecting rod up the bore and
withdraw from the top of the cylinder block.
Loosely refit the cap to the connecting rod.
5Repeat the procedure in paragraphs 3 and
4 on No 4 piston and connecting rod, then
turn the crankshaft through half a turn and
repeat the procedure on Nos 2 and 3 pistons
and connecting rods.
Refitting
6Commence refitting as follows.
7Clean the backs of the bearing shells and
the recesses in the connecting rods and big-
end caps.
8Press the bearing shells into the connecting
rods and caps in their correct positions and oil
them liberally. Note that the lugs in
corresponding shells must be adjacent to
each other (see illustration).
9Lubricate the cylinder bores with clean
engine oil.10Fit a piston ring compressor to No 1
piston, then insert the piston and connecting
rod into No 1 cylinder (see illustration). With
No 1 crankpin at its lowest point, drive the
piston carefully into the cylinder with the
wooden handle of a hammer, and at the same
time guide the connecting rod onto the
crankpin. Make sure that the arrow on the
piston crown is facing the front of the engine.
11Oil the crankpin, then fit the big-end
bearing cap in its previously noted position,
and tighten the nuts to the specified torque.
12Check that the crankshaft turns freely.
13Repeat the procedure given in paragraphs
11 to 13 inclusive on the remaining pistons.
14Refit the cylinder head and the sump.
1Examine the pistons for ovality, scoring,
and scratches. Check the connecting rods for
wear and damage. The connecting rods carry
a letter indicating their weight class; all the
rods fitted must be of the same class.
2The gudgeon pins are an interference fit in
the connecting rods, and if new pistons are to
be fitted to the existing connecting rods, the
work should be carried out by a Ford dealer
who will have the necessary tooling. Note that
the oil splash hole in the connecting rod must
be located on the right-hand side of the piston
(the arrow on the piston crown faces forwards).
3If new rings are to be fitted to the existing
pistons, expand the old rings over the top of
the pistons. The use of two or three old feeler
blades will be helpful in preventing the rings
dropping into empty grooves. Note that the oil
control ring is in three sections.
33Pistons and connecting rods
- examination and renovation
32Pistons and connecting rods
- removal and refitting
2A¥22SOHC engines
31.10a Checking the oil pump outer rotor-
to-body clearance31.11 Checking the oil pump rotor endfloat
32.10 Fitting a piston ring compressor32.8 The bearing shell lugs (arrowed) must
be adjacent to each other32.2 Big-end cap and connecting rod
identification numbers
31.10b Checking the oil pump inner-to-
outer rotor clearance