1994 JAGUAR XJ low oil pressure

AJ16 Engine Service Manual
Exhaust Manifold
Exhaust manifold to cylinder head
Heatshield to exhaust manifold
Lifting eye setscrew (slave item only)
.~ Fuel System
Fuel pressure regulator to bracket
Fuel rail connecting nut
. i------
44,5 - 59.5
21.5
- 28,5
21.5 - 28,5
~- 30.5 - 41,5
12,5 - 15,5
Fixing
- Adjuster bracket to oil pan
Adjuster sleeve
to generator
Generator mounting bracket pivot bolt
Sleeve to adjuster bolt
21,5 - 28,5
17 - 23
34
- 46
11 - 15
__~___.___ 21.5 - 28,5 __ ~~ ~ Generator
Mounting
bdjuskr bolt to timing cover
Intake Manifold
Blanking plate to intake manifold (in place of adapter) 9,5 - 12,5
8,5- 11,5
9,5 - 12,5
36 - 44
14.5
- 19.5
LBreather adapter to intake manifold (4,O liter normally aspirated)
l EGR adapter to intake manifold
EGR pipe to adapter
EGR sensor to intake manifold 1
1 Intake manifold steady screw (4,O liter supercharged)
Intake manifold
to cylinder head
Pedestal to throttle body
22 - 28
21,5 - 28,5
9,5 - 12,5
Pressure regulator to intake manifold
Pressure regulator to intake manifold
(4.0 liter supercharged)
9,5 - 12,5
5-7
Throttle linkage baseplate to pedestal
assembly nut
Purge adapter
to intake manifold
Throttle body to intake manifold
9,5 - 12,5
21,5 - 28,5
9,5 - 12.5
1.8 - 2,2
'Throttle cable abutment to intake manifold
Throttle linkage actuator nut
9,5 - 12,5
Throttle stop screw locknut
Miscellaneous Hoses
Hose clamp, breather hose to restrictor
Hose clamp, heater return hose to throttle body
4,3 - 5,7
1.5
- 2,5
1,5
- 2.5
Hose clamp, hose to cam cover 2,5 - 3.5
' Hose clamp, restrictor to throttle body
I Oil cooler clamp screw 5-7
1.5
- 2,5
Oil
cooler pipe bracket screw 1.5 - 2.5
l Hose clamp, thermostat housing to restrictor ~
Hose
clamp, water pump
Oil Cooler (4.0 Liter Supercharged)
Hose clamp, oil cooler hose to radiator cradle
..
Oil cooler pipes to engine 14-18
1,5
- 2,5
2,5
- 3.5
7
-10
Oil cooler to body
Tube nut, all except those shown below 17 - 23
17
- 23
16 - 20 ,Tube nut, transmission pipes to transmission
Issue 1 August 1994 ix

AJ16 Engine Service Manual
0 GENERAL DESCRIPTION - The engine is available as a 3,2 and 4,O liter unit. A 4,O liter supercharged version is also available. Fuel is supplied
to each cylinder via an injector fed from a regulated fuel rail. To comply with statutory regulations in some countries
and to reduce emissions during the warm
-up period, secondary air is delivered to the exhaust manifold by an electri- cally operated air injection pump. This improves oxidation until the catalytic converters are fully effective. All engine
functions are controlled by an integrated engine management system, which incorporates the on-board diagnostic
system (OBDII).
1.1 Construction
The skirted design crankcase is manufactured in cast aluminum alloy with shrink fit dry cast iron cylinder sleeves.
Thecrankshaft ismanufactured from cast
ironforthe3,2 literengine,forged steel forthe 4,O liter engineand is nitro-car-
burize treated to give a very high quality finish on the bearing surfaces and increase the life of the journals.
The crankshaft is supported by seven iron bearing caps having bearings, which are lead bronze on split steel backed
shells with a lead indium overlay.
Crankshaft end
-float is controlled by half thrust washers fitted on each side of the center main bearing journal. The
connecting rods are manufactured from carbon manganese steel, forged in an 'H' section. The small end bushes are
lead bronze with steel backing, machined to size after being pressed into the connecting rods. The connecting rod bear- ings are of a lead bronze alloy on split steel backed shells and with lead indium overlay.
The pistons are of monometal construction (aluminum) and have a spring assisted micro
-land oil control ring situated
below a barrel-faced internally tapered chrome plated compression ring and an externally stepped taper-faced second-
ary ring.
The cylinder head is cast from aluminum alloy with pent
-roof shaped combustion chambers with cross-flow valve
porting. Running directly in the cylinder head are
twocast iron camshafts retained by machined aluminumcaps. Each
camshaft uses chilled cams to drive two valves per cylinder via chilled cast iron bucket tappets with shim adjustment.
Control of each of the four valves per cylinder is maintained by single valve springs.
The camshafts are operated by a two stage 'duplex' chain drive from the crankshaft. Each stage is controlled by a hy
- draulic tensioner operating through a pivoted rubber-faced curved tensioner blade. The first stage incorporates a three
point drive via the crankshaft, intermediate shaft and auxiliary shaft. The intermediate shaft is live and provides a 0.75 x crank speed drive through the timing cover. This drive access is blanked off. The 'live' auxiliary shaft is driven at
crankshaft speed and is situated on the right hand side of the engine (looking from rear). In addition to driving the
engine position sensor via a set of 2 : 1 reduction spiral gears, it provides an external drive for the power assisted steer- ing pump at the rear. The second stage is a three point drive via the intermediate shaft and two camshafts. The 2:l reduction ratio from crank speed is achieved by the combined ratio of the intermediate and camshaft sprockets sizes.
The oil pump is a rotor
-type mounted on the underside of the front of the crankcase and driven by a 'simplex' chain
from the crankshaft nose. The pump incorporates a built-in pressure relief valve. Below the line of the crankcase, but
abovetheoil pan
oillevel aretwowindagetrays; these prevent oil beingsucked upand thrown into thecrankcasethere- by alleviating windage and power losses through oil surge.
At the rear of the crankshaft is
a new design of lip-type PTFE oil seal which provides a high degree of oil retention. It also allows the use of higher engine speeds and easier serviceability.
1.2 Cylinder Head Design
The four valves per cylinder are smaller in diameter than on a conventional two valve per cylinder engine and have a greater combined effective area. They are also lighter and apply less stress to the operating gear. The design in- creases the power at high engine speeds and allows an efficient combustion of the fuel. It also allows the spark plug
to besituated in its ideal central position which creates efficient combustion and consequently enhancesfuel economy.
1.3 Crankcase Breather
Blow-by gases are recycled via the air intake system to maintain a crankcase depression and so prevent their escape
to the atmosphere. A baffled vent from the camshaft cover is used for both full and part load breathing. For full load
breathing,
a connection is made direct to the clean side ofthe air filter upstream ofthe throttle disc. Part load breathing is provided by a spur off the full load pipe to downstream ofthe throttle disc via the water heated restrictor. In this way,
a crankcase depression is maintained at all throttle settings.
1.4 Lubrication System
Oil is drawn from the oil pan via a gauze filter. Pressurized oil, having been regulated by a relief valve, is then fed via
internal galleries on the left hand side of the cylinder block. Pressurized and filtered oil is fed into the main oil gallery,
the seven main bearings are fed and thence via crankshaft drillings to the connecting rod bearings. The intermediate
shaft, auxiliary shaft and camshaft bearings are pressure lubricated by means of internal drillings directly fed from the
front of the main oil gallery. For some markets an oil cooler is fitted to vehicles with
4,O liter supercharged engines.
The pistons run on hardened steel piston pins offset from the center line of the piston towards the thrust face.
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AJ16 Engine Service Manual
FAULT DIAGNOSIS
3.1 Introduction
The following diagnostic procedures are provided to assist properly qualified persons to identify and rectify the faults
relating to the engine which are most likely to encountered. Reference is made to the Electrical Diagnostic Manual
(EDM), which should be consulted where necessary. Faults related to the cooling system are dealt with in Section 4.1
and to the fuel system in Section 5.1 in the appropriate Vehicle Service Manual (VSM).
3.2 Diagnostic Procedures
(fails to rotate)
I Engine rotates but 0 I will not fire
I
i
/Overheating
Overheating at tick-
Too cold
Loss of coolant Possible
Cause
Battery leads loose or ter
- minals corroded
Battery discharged
Starter motor inoperative
Starter motor speed too
low
Faulty ignition system
Fuel system defect
Oil requires changing
Worn crankshaft journals
Excessive crankshaft
end- float
Worn main bearing shells
Worn oil pump Oil pressure relief valve stick
- ing open
Oil pressure relief valve
spring too weak
Insufficient oil in oil pan
Engine overheating
Faulty gauge or sensor
Incorrect grade oil (viscosity
too low)
Water in oil Check
Check the condition of the
leads and terminals
Check condition of battery
with hydrometer
If the lights dim when ignition
switch is operated, the starter
may be jammed in starter
ring.
Check for loose and dirty con
- nections to the starter motor
Check battery leads and ter
- minals
Check state of battery charge
Refer to EDM
Remove the spark plugs
Check oil level and color
Listen for rumble or knock
Fit dial gauge and measure
Listen for rumble
Remove oil pump and check
the clearances
Remove valve and check for
sticking
Remove spring and check
spring rates
Check oil level
Refer to EDM
Check oil viscosity
Checkoil level and check if oil
is a milky white color
Check for leaking head gasket Remedy
Clean and tighten as necess
-
ary
Charge or renew battery as
necessary
Remove starter motor, free
off pinion and refit
Clean and tighten connec
- tions
Clean and tighten terminals
Charge or renew battery
as necessary
Rectify as required
Clean and re
-gap the spark
plugs, renew if worn out
Refer to Fuel System fault
finding in Section
5.1, VSM
Refer to Section
4.1, VSM
Refer to Section
4.1, VSM
Refer to Section
4.1, VSM
Refer to Section
4.1, VSM
Change oil and filter
Renew crankshaft
Renew thrust washers
Check crankshaft journals for
wear and renew shells
Renew oil pump
Renew valve
Renew spring
lop-up as required
Refer to Overheating fault
finding in Section
4.1, VSM
Rectify as required
Renew oil and filter
Renew oil and filter
Renew head gasket
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AJ16 Engine Service Manual
Symptom Possible Cause ~~
nsufficient
oil pres- ure (continued)
lil pressure too high
3urning oil
.osing oil (leaking)
Excessive noise
'rom valve gear Cracked
oil pump housing
Blocked oil pick
-up pipe
strainer
Oil pump pipe
'0' rings
Main oil gallery seals leaking
or gallery blocked
Relief valve stuck shut
Wrong pressure relief valve
Incorrect grade engine oil
(viscosity too high)
Gauge or sensor fault
Engine temperature too low
Worn cylinder bores
Worn valve guides
Worn intake valve seals
Worn piston rings
Cylinder head gasket leaking
Incorrect grade of engine oil
Worn front oil seal
Worn rear oil seal
Leaking gaskets
Cylinder block cracked
Excessive valve clearance
Broken valve
spring(s)
Broken valve guide
Broken valve seat insert
Lack of lubrication
Valve clash
Worn
camshaft(s)
Worn camshaft drive chains i tensioners
Check
Remove oil pan and visually
check
Remove oil pan and visually
check
Removeoil
panand pipesand check Eliminate other possible
causes
Remove valve and check for
sticking
Remove spring and check the
rate
Check oil viscosity
Refer to EDM
Check wear with
a compara- tor
Insert valve in guide and
check side movement
Remove seals and check for
splits or wear
Measure rings in bore
Check for blue smoke from
exhaust
Check oil viscosity
Wipe clean, run engine and
visually check
Wipe bell housing clean, run
engine and visually inspect
for cleanliness
Visual check
Visual check
Check valve clearances
Remove valves and check
springs
Remove valves and check
guides
Remove valves and check in
- serts
Check oil pressure gauge re
- ading
Check valve timing
Check valve clearances and
for lack
of lubrication
Remove front timing cover
and check for wear
Remedy
Renew the pump
Remove oil pick
-up pipe and
clean strainer
Fit new '0' rings
Fit new '0 rings or clear oil
gallery
Clean or renew the valve
Renew spring
Renew oil and filter
Rectify as required
RefertoToo Cold fault finding
in Section 4.1, VSM
Rebore cylinders as necess
-
ary
Renew valve guides as
necessary
Renew in sets
Renew rings in sets and re
- bore as necessary
Renew head gasket
Renew oil and filter
Renew seal
Renew seal
Renew gasket Renew cylinder block
Adjust valve clearances
Renew as necessary
Renew as necessary
Renew as necessary
Refer to Insufficient Oil Pres
- sure fault finding
Adjust valve timing
Adjust valve clearances.
Refer to Insufficient Oil Pres
- sure fault finding
Renew as
necessaw
0
0
0 ~~~
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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
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AJ16 Engine Service Manual
Fit a new linkto the drive chain (2 Fig. 1).
Fit and align a link plate to Service Tool JD 130 (1 Fig. 1).
Ensure that the link and tool clamp holes are aligned. Fit the tool /link plate assembly to the drive chain.
. Fit the ‘E’ gate (3 Fig. 1) to the tool and chain link. Ensure
that the chain is central to the tool. Tighten the tool center
bolt, fully seating the plate
on to the link.
Slacken off the tool center bolt.
. Re-position the tool clamp (4 Fig. 1) away from the chain.
Locate the link riveting head on to the
clamp. Tighten the
tool center bolt (finger tight, then further /2 to 3/4 turn).
Slacken off the tool center bolt. Remove the tightening
bar.
Re-position the clamp away from the chain.
Re-position the ‘E’ gate away from the tool / chain. Re- move the tool retaining handle and remove the tool.
Attach a dial test indicatorto the topof the engine with the
stylus resting on a piston. Rotate the engine and set No. 1 cylinder (Fig. 2) at TDC. Refit the lower static damper. Fit and tighten the securing bolts and lock over the tab
washer. Fit the oil pump chain damper in position, do not
tighten the securing bolts at this stage. Take any slack out
of the chain using hand pressure to push the damper to
- wards the center of the engine.
Tighten the bolts securing the damper.
. Lubricate the intermediate sprocket bearing.
Lift up the chain, engage the sprocket in the chain, and lo-
cate the sprocket into the bearing.
. Refit the lower tensioner assembly.
. Lubricate the upper timing chain.
. Refit the upper chain to the intermediate sprocket.
. Refit the upper static damper.
Fit and tighten the securing bolts.
Refit the upper tensioner.
. Renew the oil seal (1 Fig. 3) and refit the timing cover.
Fig. 1
-v II
Fig. 2
.12-Kl
Fig. 3
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AJ16 Engine Service Manual
4.20
SRO 12.65.48
Remove the timing cover.
1 Remove the upper tensioner pedestal flanged securing
bolts (3 Fig. 1).
Remove the pedestal / tensioner assembly and chain
damper
(1 Fig. 1).
Remove the tensioner pivot pin (2 Fig. 1) and remove the
tensioner from the pedestal.
. Remove the flanged bolts (5 Fig. 1) securing the upper
static damper and remove the damper (4 Fig. 1) and re-
move the damper pedestal.
1 Remove the lower timing chain tensioner securing bolts (11 Fig. 1) and remove the tensioner assembly (10, 12
Fig. 1).
1 Remove the bolts (16 Fig. 1) securing the oil pump drive
chain damper, remove the damper (17 Fig. 1).
1 Remove the flanged bolts (14 Fig. 1) securing the lower
static damper, and remove the damper
(15 Fig. 1).
Clean all component parts and checkfor wear or damage,
renew worn or damaged components as necessary.
1 Fit the oil pump chain damper in position, do not tighten
the securing bolts
at this stage. Take any slack out of the
chain using hand pressure to push the damper towards
the
center of the engine and tighten the damper securing
bolts.
Timing Chain Damper, Vehicle Set, Renew
1 Refit the lower tensioner assembly.
Refitthe upper static damper. Fit and tighten thesecuring
bolts. Refit the upper tensioner.
Renew the timing cover oil seal and refit the timing cover.
1 13 19 18 17
Fig. 1
Issue 1 August 1994 40

D
Drive belt tensions, xvi
F
Fau It diagnosis
Diagnostic procedures, 3
Introduction, 3
Foreword, iii
General description
Construction, 1
Cooling system, 2
Crankcase breather, 1
Cylinder head, 1
Lubrication system, 1
Supercharger, 2
S
Service data, xiii
Service materials, xii
Service operations
Check & adjust
Crankshaft end
-float, 27
Valve clearances, 10
Cylinder head, 16
Engine assy., 33
Oil pump, 52
Auxiliary shaft, 44
Auxiliary shaf? rear seal, 45
Camshaft, 7
Camshaft cover gasket, 9
Connecting rod bearings, 22
Crankshaft, 24
Crankshaft damper /pulley assy., 26
Crankshaft front oil seal, 28
Crankshaft rear oil seal, 29
Cylinder head casting, 19
Cylinder head gasket, 13
Drive-plate, 31
Flywheel, 30
Main bearings, 23
Oil filter head gasket, 46
Oil pan gasket, 47
Oil pick-up strainer, 49
Oil pressure relief valve, 50
Oil pump, 51
Oil pump pipe ‘0’ ring, 48
Pistons &connecting rods, 20
Timing chain damper, 40
Timing chain tensioner
Overhaul
Renew
Lower,
42
Upper, 41
Timing chain, gear & tensioner, 37
Timing sprocket, Intermediate, 43
Transmission adapter plate, 32
Service procedures
Sealants, 2
SPS joint control system, 2
Service tools & equipment iv
T
Torque tightening specifications,
53