key JAGUAR XJ 1994 2.G AJ16 Engine Manual
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Page 24 of 73

AJ16 Engine Service Manual
Symptom
Joisy chains
)etonation knock pinking)
.oss of power
Gugh running at iormal engine speed Possible
Cause
Low oil pressure
Tensioners not released
Chains worn
Sprockets worn
Tensioner worn
Ignition timing too far ad
- vanced
Head gasket leaking
Fuel
/ air mixture too weak
Engine running
too hot
Valve timing incorrect
Incorrect grade fuel
Burned valves Sticking valves
Poor engine tune
Insufficient valve clearance
Fuel injection fault
Lowcompression in cylinders
Ignition fault
Valve timing incorrect
Partial seizure of engine
Worn
camshaftb)
Incorrect grade fuel
Sticking valves Broken valve springs Piston fault
Leaking head gasket
Valve burned out
Valve seat burned out
Ignition fault
Fuel injection fault
Check
Take reading from oil pres- sure gauge when engine is
hot
Remove camshaft cover and
check tension of chain (top
chain). Remove timing cover
to check bottom chain tension
Visually check
/ remove and
check for wear
Visual check
Visual check
Refer to EDM
Check engine oil level and
checkfor contamination of oil
Pressure test cooling system
and check for contamination
of coolant in header tank
Refer to EDM
Check valve timing
If all other checks
OK, this
could be the cause
Check cylinder compressions
Check cylinder compressions
Refer to EDM
Check valve clearance
Check compressions
Refer to EDM
Check valve timing
Remove spark plugs and ro
- tate crankshaft
Remove
camshaft(s) and
check for wear
If all other checks OK this
could be the cause
Check cylinder compressions
Check cylinder compressions
and for bent valve stems
Check cylinder cornpressions
Check cylinder compressions
Check cylinder compressions
Refer to
EDM
Remedy
Refer to Insufficient Oil Pres- sure fault finding
Insert
3 mm Allen key and
turn tensioner anti-clock- wise, compress tensioner to
release bottom chain
Renew as necessary
Renew as necessary
Renew as necessary
Rectify as required
Renew head gasket
Rectify
as required
Refer
to Overheating fault
finding in Section 4.1, VSM
Adjust valve timing
Drain fuel tank and refill with
correct grade fuel
Remove cylinder head and
renew valves
Remove cylinder head and
renew valves
/ guides or
springs
Rectify as required
Adjust as necessary
Refer to Fuel System fault
finding in Section 5.1, VSM
Rebore
1 re-ring as necessary
Rectify as required
Adjust valve timing
Overhaul engine as required
Renew
camshaft(s)
Drain fuel tank and refill with
correct grade fuel
Renew valve, springs or
guides
Renew valve springs and
valves as required
Renew pistons
Refer to Detonation Knock
fault finding
Renew valve
Re
-cut or renew valve seat
Rectify as required
Refer to Fuel System fault
Tindim in Section 5.1, VSM
issue 1 August 1994 5
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AJ16 Engine Service Manual
SERVICE OPERATIONS
4.1 Camshaft, Renew
SRO 12.13.01
Remove camshaft cover, see Section 4.2.
Drain the cooling system, see Section 4.1 in the appropri
- ate Vehicle Service Manual.
1 Rotate the engine and set No. 1 cylinder at TDC using Ser- viceTool 18G 1433 (1 Fig. 1).
Push back the lock tabs (1 Fig.2) from the camshaft
sprocket securing bolts (2 Fig. 2). and slacken off the bolts.
Remove the upper chain tensioner valve clamp bolt
(3 Fig.
2), remove the clamp (4 Fig. 2) and remove the
valve (5 Fig. 2).
1 Using a 3 mm Allen key, wind backthe tensioner (6 Fig. 2) (turn clockwise) until the snail engages in the park posi- tion. Remove the tensioner housing securing bolt (7 Fig. 2) and withdraw the tensioner assembly (8, 9 Fig. 2).
1 Remove and discard the '0' ring (9 Fig. 2) and gasket (10 Fig. 2).
. Remove the camshaft sprocket securing bolts and tab
washers (1,2 Fig. 2) and remove the sprockets (11 Fig. 2) (ensure that neither the bolts nor the tab washer drop into
the timing case).
CAUTION: Do not rotate the engine while the camshaft is
disconnected.
. Remove the cylinder head bolt from No. 2 cap, left-hand
1 Remove No. 2 cap from the left-hand camshaft.
1 Fit spacer tool 18G 1435 (2 Fig. 3) to the head.
Fit and torque tighten the cylinder head bolt.
Repeat the procedure for Nos 3,4,5 and 6 caps, left-hand
camshaft (3 Fig. 3).
Remove the cylinder head bolt from
No. 7 cap, left-hand
camshaft.
Loosen in sequence the securing bolts from Nos 1 and 7 caps, until theleft-handcamshaft isfree. Liftthecamshaft
from the cylinder head and fit spacer tool 18G 1435 to No. 7 cylinder head bolt position (5 Fig. 3). Fit and torque
tighten the bolt.
Clean
all components and examine for wear and damage.
Renew all worn or damaged components.
Lubricate the new left
-hand camshaft.
Fit the camshaft at approximately TDC.
Lubricate Nos 1 and 7 caps.
Fit No. 1 cap but do not tighten the securing bolts. Remove No. 7 cap cylinder head bolt.
1 Remove the spacer tool. Fit No. 7 cap but do not tighten
the securing bolts.
1 Finally tighten Nos 1 and 7 cap securing bolts in sequence.
Remove No. 4 cap cylinder head bolt and remove the
spacer tool. Lubricate and fit No. 4 cap.
CAUTION: The cylinder head bolts MUST be renewed dur- ing assembly and torque tightened as de- scribed in Section 2.1, SPS Joint Control System.
camshaft
(1 Fig. 3).
1 Repeat
the procedure for the right-hand camshaft.
1
Fia. 1
Fia. 2
Fig. 3
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AJ16 Engine Service Manual
4.3
SRO 12.29.48
1 Remove camshaft cover, see Section 4.2.
1 Rotate the engine as necessary to measurethevalve clear- ances between the heel of the cam and the cam follower
(Fig.
1). See Service Data in the Preliminary Pages for the
correct valve clearances.
1 Make a note of each clearance measurement.
1 Should the clearances be incorrect, proceed as follows:
1 Rotate the engine and set No. 1 cylinder at TDC using Ser- viceTool 18G 1433 (1 Fig. 2).
Push back the lock tabs (1 Fig. 3) from the camshaft
sprocket securing bolts (2 Fig. 3).
1 Slacken off the bolts and tab washers.
1 Remove the upper chain tensioner valve clamp bolt
(3 Fig. 3), remove the clamp (4 Fig. 3) and remove the
valve (5 Fig. 3).
1 Using a 3 mm Allen key, wind back the tensioner (turn
clockwise) until the snail engages in the park position.
1 Remove the tensioner housing securing bolt (7 Fig. 3) and
remove the tensioner assembly (8,9 Fig. 3).
1 Remove and discard the '0' ring (9 Fig. 3) and gasket (10 Fig. 3).
1 Remove the camshaft sprocket securing bolts/tab washers (1,2 Fig. 3) and remove the sprockets (1 1 Fig. 3).
1 Remove the cylinder head bolt from No. 2 cap, left-hand
camshaft (1 Fig. 4).
1 Remove the cap securing bolts from No. 2 cap, left-hand
cams haft.
. Remove No. 2 cap from the left-hand camshaft.
1 Fit spacer tool 18G 1435 (2 Fig. 4) to the head.
1 Fit and torque tighten the cylinder head bolt.
1 Repeat the procedure for Nos 3,4,5 and 6 caps, left-hand
camshaft
(3 Fig. 4).
1 Remove the cylinder head bolt from No. 7 cap, left-hand
camshaft.
1 Loosen in sequence the securing bolts from Nos 1 and 7 caps, until the left-hand camshaft is free. Lift the camshaft
from the cylinder head and fit spacer tool 18G 1435 to No. 7 cylinder head bolt position (5 Fig. 4). Fit and torque
tighten the bolt.
Valve Clearance, Check and Aa'just
1 Repeat the procedure for the right-hand camshaft.
CAUTION: The cylinder head bolts
MUST be renewed dur- ing assembly and torque tightened as de- scribed in Section 2.1, SPS Joint Control
System.
111 ...
Fig. 1
1
Fig. 2
Fig. 3
Fig. 4
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AJ16 Engine Service Manual
1 Move all the slack in the chain to the tensioner side.
1 Fit upper chain tensioner tool 18G 14361A (2 Fig. 1). Fit and
tighten the tool securing bolts (1 Fig. 1).
1 Tension the cam chain.
1 Remove the camshaft coupling (12 Fig.2) from the
sprocket (11 Fig. 2) and align the securing bolt holes. Fit
the bolts (2 Fig. 2) and tab washers (1 Fig. 2), tighten the
securing bolts and lock over the tabs.
1 Repeat the procedure for the other sprocket.
1 Slacken off the chain tensioner tool securing bolts
1 Remove the tensioner tool.
1 Clean the tensioner assembly and gasket faces.
= Fit a new housing gasket (10 Fig. 2). Fit and lubricate a
new ‘0’ ring (9 Fig. 2).
1 Fitthetensionerassembly (8,9 Fig. 2)tothecylinderhead.
Fit andtighten thetensioner assembly securing bolt (3 Fig.
2).
(1 Fig. 1).
1 Fit but do not tighten the valve clamp bolt.
1 Clean the valve assembly and fit new ‘0‘ rings (13 Fig. 2).
Lubricate the tensionervalve (5 Fig. 2). Using an Allen key,
release the tensioner, by turning the
Allen key anti-clock- wise.
1 Fit the tensioner valve (5 Fig. 2). Position the clamp (4 Fig. 2) over the valve.
1 Tighten the clamp bolt (3 Fig. 2).
1 Refit the camshaft cover, see Section 4.2. Fig.
1
I Fia. 2
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AJ16 Engine Service Manual
4.4 Cylinder Head Gasket, Renew
SRO 12.29.01
Drain the cooling system, see Section 4.1 and depressurize
the fuel system,see Section 5.1 (thesesections are in the ap- propriate Vehicle Service Manual). Disconnect the exhaust
system with the vehicle supported on axle stands. Remove
components as required for access to the cylinder head and
proceed as follows.
1 Rotate the engine to TDC No. 1 cylinder.
1 Remove the camshaft cover, see Section 4.2.
1 Push backthe lock tabs and remove the camshaft sprocket
securing bolts (2 Fig. 1). Remove the tab washers (1 Fig. 1).
1 Remove the upper chain tensioner valve clamp bolt (1 Fig. 2), remove the clamp (2 Fig. 2) and remove the
valve (3 Fig. 2).
1 Using a 3 mm Allen key, wind back the tensioner (turn
clockwise) until the snail engages in the park position.
1 Remove the tensioner housing securing bolt (4 Fig. 2) and
withdraw the tensioner assembly.
1 Re-position thetiming chain between the upper dampers.
1 Remove the cylinder head front securing bolts.
1 Remove the remaining cylinder head securing bolts/ nuts.
Remove the upper static damper pedestal assembly and
remove the cylinder head.
0 1 Fit an elastic band to retain the dampers and chain.
. Remove and discard the head gasket.
1 Remove and discard the exhaust manifold sealing rings.
1 Place the cylinder head on suitable blocks on a bench.
Clean the cylinder head thoroughly and check the cylinder
head and cylinder block for warping, bowing or cracks.
Renew if defective.
1 Fit a new cylinder head gasket.
1 Fit the cylinder head assembly to the engine, ensure no
hoses or cables are trapped.
A2616
Fig. 1
Fin. 2
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AJ16 Engine Service Manual
= Refit the upper static damper assembly.
lighten the cylinder head bolts with reference to the se- quence shown in Fig. 1.
CAUTION: The cylinder head bolts MUST be renewed dur- ing assembly and torque tightened as de-
scribed in Section 2.1, SPS Joint Control
System.
Ensure that the camshaft is still on TDC using Ser
-
vice Tool 18G 1433 (1 Fig. 2).
Fit the harness clip and hose bracket to the cylinder head
front securing bolts.
Fit and tighten the front securing bolts.
1433 (1 Fig. 2).
b:
= Check the camshafts are set atTDC using Service Tool 18G
= Raise the timing chain from between the upper dampers.
Remove the elastic band.
= Fit and engage the sprockets to the chain and camshafts.
. Move all the chain free play to the tensioner side.
Fit upper chain tensioner tool 18G 1436/A (2 Fig. 3).
Fit and tighten the tool securing bolts (1 Fig. 3).
Tension the timing chain.
sprocket
(1 1 Fig. 4) and align the securing bolt holes.
bolts
(2 Fig. 4). Lock over the tabs.
Release the tension on the timing chain.
Re
-position the
chain over the camshafts.
. Remove the camshaft coupling (12 Fig. 4) from the
. Fit the tab washers (1 Fig. 4). Fit and tighten the securing
. Slacken off the upper chain tensioner tool securing bolts.
Remove the upper chain tensioner tool 18G 14361A (2 Fig.
Clean the tensioner assembly and gasket faces.
3).
Fit a new housing gasket (10 Fig. 4). Lubricate andfita new '0' ring (9 Fig. 4).
. Fit the tensioner to the cylinder head.
. Fit and tighten the tensioner assembly securing bolt
Clean the valve assembly and fit new '0' rings.
Using an Allen key, release the tensioner, ie turn the Allen
(4 Fig. 3).
Lubricate the tensioner valve.
key
anti-clockwise.
I
104 2 5 7 I l2
I Fig. 1
1
Fig. 2
Fig. 3
Fig. 4
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AJ16 Engine Service Manual
4.10 Crankshaft, Renew
SRO 12.21.33
m Remove the engine and transmission unit from the ve-
hicle, see Section 3.1 in the appropriate Vehicle Service
Manual.
Detach the transmission unit from the engine.
Fit the engine to a stand.
Remove the cylinder head, see Section 4.4.
. Remove the crankshaft damper pulley assembly, see Sec-
. Remove the oil pan , see Section 4.27.
Remove the oil pump, see Section 4.31.
. Remove the flywheel (Manual), see Section 4.15, or re-
. Remove the timing cover.
. Remove the windage trays securing bolts (1 Fig. 1) and re- move the windage trays (2 Fig. 1).
Remove the timing chains - upper and lower and the
upper and lower tensioners see Section 4.19.
. Remove theseal/crankshaft damper spacer, the woodruff
key (1 Fig. 21, the crankshaft sprockets (2 Fig. 2) and the
inner woodruff key.
tion
4.11.
move the drive
-plate (Automatic), see Section 4.16.
. Remove the rear oil seal housing, see Section 4.14.
Remove the connecting rod bearing nuts and remove the
connecting rod bearing caps in pairs
(1-6,2-5,3-4), turn- ingthecrankshaftfor accessas required. As each connect- ing rod bearing cap is removed, ensure that each
connecting rod and connecting rod bearing cap are identi- fied to each other for re-pairing during assembly.
. As each cap is removed, its relative connecting rod and
piston assembly should be pushed up the bore, enabling
the crankshaft to be rotated to remove the remaining caps.
Care should be taken not to push the piston too far up the
cylinder bore as this will release
the piston rings.
Ensuring that the main bearing caps are marked relative
to the cylinder block (1 Fig. 3), remove the main bearing
cap bolts and the bearing caps, and carefully lift out the
crankshaft.
Remove and discard the bearing shells and the thrust
washers.
. Clean the bearing caps and the cylinder block main bear- ing housings.
Fit the new bearing shell halves to the cylinder block and
lubricate with clean engine oil.
Fig. 1
!- ,1101,
Fig. 2
Fig. 3
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AJ16 Engine Service Manual
1 Clean and polish the crankshaft journals, lubricate and
carefully assemble the crankshaft into the cylinder block,
fit the thrust washers ensuring that the steel side of the
washer is mated to the cylinder block (1 Fig. 1).
1 Rotate the crankshaft to ensure that it turns freely.
1 Fit the main bearing shells into the main bearing caps, lu- bricate and fit to the cylinder block.
1 Start the securing bolts and carefullytap the main bearing
caps to ensure they are seated to the cylinder block.
1 Rotate thecrankshaft to ensurethat it still turnsfreely, pull
down each bearing cap individuallyand torque tighten the
securing bolts.
1 Rotate the crankshaft between pulling down each bearing
cap.
1 Check and if necessary adjust the crankshaft end-float in
accordance with Section 4.12.
1 Renew the crankshaft rear oil seal, see Section 4.14.
1 Fit a new bearing shell to the connecting rod, lubricate
1 Fit a bearing shell to theconnecting rod bearing cap, lubri-
with clean engine oil and fit to the crankshaft.
cate and fit to the connecting rod.
Fit and torque tighten
1 Turn the crankshaft over ensuring that there are no 'tiaht'
the nuts.
spots, and that the crankshaft rotates freely.
-
1 Repeat this procedure for the remaining five cylinders.
WUTION: The connecting rod bearing nuts, bolts and
main bearing securing bolts MUST be renewed during assembly and torque tightened as de- scribed in Section 2.1, SPS Joint Control Sys- tem.
1 Clean and inspect for wear or damage all the timing gears,
chains, guides and tensioners.
1 Renew any suspect component.
1 Fit and seat the crankshaft sprocket woodruff key and fit the sprocket to the crankshaft.
1 Refit the timing chains - upper and lower; and the upper
and lower tensioners, see Section 4.19.
1 Fit a dial gauge to the top ofthe cylinder blockand turn the
engine over until No.1 and 6 pistons are at TDC (Fig. 2).
1 Lubricate the upper chain and fit it to the intermediate
sprocket.
0 1 Fit an elastic band to retain the upper dampers and chain.
. Lubricate the oil pump drive chain, fit the chain to the
crankshaft sprocket and lodge in the correct position.
1 Renew the timing cover oil seal and refit the timing cover.
. Lubricate and fit the oil seal distance piece. Fit and seatthe
1 Refit the oil pump, see Section 4.31.
1 Refit the flywheel (Manual), see Section 4.15, or refit the
1 Refit the oil pan, see Section 4.27.
1 Refit the crankshaft damper /pulley assembly, see Section
1 Refit the cylinder head, see Section 4.4.
1 Remove the engine from the stand and refit the trans-
1 Refit the engine/transmission unitto thevehicle, see Sec-
damper woodruff key.
drive
-plate (Automatic), see Section 4.16.
4.11.
mission unit.
tion
3.1 in the appropriate Vehicle Service Manual.. Fig.
1
Fig. 2
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AJ16 Engine Service Manual
4.18 &;ne Assembly, Overhaul
SRO 12.41.05
. Remove the engine and transmission unit, see Section 3.1
. Remove the transmission unit from the engine.
. Fit the engine to a stand.
. Place a drain tray belowthe cylinder block drain plug and
Overhaul the cylinder head, see Section 4.5.
1 Remove the oil pan, see Section 4.27.
. Remove the oil pump, see Section 4.31.
. Remove the windage trays.
. Clean all components, check for damage and wear and
. Remove the rear oil seal housing, see Section 4.1 4.
. Remove the timing cover assembly.
1 Remove the pedestal bolts and tab washer.
. Remove the pedestal / tensioner assembly and damper.
Slacken off the oil pump drive chain damper securing
bolts and move the damper clear of the chain. Push back
the lock tabs
(1 Fig. 1) and remove the securing bolts (2
Fig. 1) from the oil pump drive sprocket (3 Fig. 1).
in the appropriate Vehicle Service Manual.
drain any remaining coolant from the engine.
renew as required.
. Remove the drive sprocket and shim pack.
. Remove the oil pump drive chain (5 Fig. l), remove the
elastic band from the upper dampers and remove the
upper timing chain.
1 Remove the lower tensioner securing bolts and remove
the tensioner.
. Push back the lower chain fixed damper securing bolt lock
tabs and remove the bolts.
. Remove the damper and tab washer.
. Repeat for the remaining fixed and pivot dampers and re- move the lower chain and intermediate sprocket.
Remove the crankshaft pulley spacer and the crankshaft
pulley woodruff key.
= Remove the drive sprockets and woodruff keys from the
crankshaft.
1 Checkall drive sprocketsforwear, distortion and damaged
teeth. Renew as required.
. Remove the power assisted steering pump assembly, see
Section 10 in the appropriate Vehicle Service Manual and
reposition away from the timing cover area.
. Renew the auxiliary shaft, see Section 4.24.
1 Renew the auxiliary shaft bushes, see Section 4.19.
1 Remove the oil pump drive chain damper.
. Remove the spacers from behind the damper.
. Remove the pistons and connecting rods and renew, see
Section 4.7.
. Refit the connecting rod bearing shells to one connecting
rod and cap and fit the rod to the crankshaft. Torque
tighten
the nuts and checkthe side clearance between the end face of the rod and the journal shoulder (Fig. 2) -see
Service Data in the Preliminary Pages.
Remove the connecting rod from the crankshaft.
. Repeat for the remaining five connecting rods. Fig.
1
Fig. 2
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AJ16 Engine Service Manual
0 1 Insert each new piston ring into the cylinder bore, (1 Fig. 1) ensuring they are square in the cylinders and checkthe gap using a strip gauge (2 Fig. 1).
. If the gap is insufficient, then a small flat file or carborun- dum stone can be used on the butting ends of the ring. En- sure that after filing no burrs remain.
Ensure that the rings are not inter
-mixed after they
have been gapped and that each piston/ring assem- bly is matched to its respective bore.
Measure the piston skirt clearance using a long strip
gauge. Insert the strip gauge down the right-hand side of
the cylinder bore, insert the correct piston INVERTED into
the bore (with the piston pin parallel to the axis of the
crankshaft).
. Push the piston down the cylinder until it reaches its
tightest point in the bore. At this point, withdraw the strip
gauge; a steady resistance should be felt.
1 If the tolerances are outside those given in Service Data in
the Preliminary Pages, the pistons must be renewed as a
complete set.
Note:
0
Fit the new main bearing shell halves to the cylinder block
and lubricate with clean engine oil.
1 Clean and polish the crankshaft journals (remove any
scratches with lapping tape, polishing in an anti-clockwise
direction ONLY. against the crankshaft rotation), lubricate
with clean engine oil and carefully assemble the crank
- shaft into the cylinder block.
1 Fit the thrust washers ensuring that the grooved bearing
Check the crankshaft rotates freely.
1 Fit the remaining new bearing shell halves into the main
1 Lubricate with clean engine oil.
. Fit the caps to the cylinder block.
1 Start off the securing bolts (approximately 2 or 3 turns)
and very gently tap the main bearing caps to ensure they
are seated on the cylinder block.
face contacts
the crankshaft
(1 Fig. 2).
bearing caps.
= Check the crankshaft still rotates freely.
. Pull down each bearing cap individually and torque
1 Check the crankshaft still rotatesfreely after pulling down
tighten
the bolts.
each bearing cap.
Check the crankshaft end-float, see Section 4.12.
. Fit new woodruff keys to the crankshaft, never re-use old
. Fit the timing and oil pump sprockets to the crankshaft.
1 Check the connecting rods for parallelism, twist and bend,
If any connecting rod is unusable, then the complete set
1 Lubricate the small end bush, slide the piston pin through
ones.
using
a suitable measuring jig (Figs.
3 and 4).
must be renewed.
the piston and connecting rod. Fia.
1
Fig. 2
Fig. 3
Fig. 4
Issue 1 August 1994 35