1997 JAGUAR XJ6 oil pressure

attached to the bolt threaded into the
front of the crankshaft. Apply pressure on
the bolt in a clockwise direction only.
Never turn the bolt anti-clockwise.
b) A remote starter switch, which may save
some time, can also be used. Follow the
instructions included with the switch.
Once the piston is close to TDC, use a
socket and ratchet as described in the
previous paragraph.
c) If an assistant is available to turn the
ignition switch to the Start position in
short bursts, you can get the piston close
to TDC without a remote starter switch.
Make sure your assistant is out of the car,
away from the ignition switch, then use a
socket and ratchet as described in
Paragraph a) to complete the procedure.
5Note the position of the terminal for the
number one spark plug lead on the distributor
cap. If the terminal isn’t marked, follow the
plug lead from the number one cylinder spark
plug to the cap.
6Use a felt-tip pen or chalk to make a mark
on the distributor body directly under the
number one terminal (see Chapter 5).
7Detach the cap from the distributor and set
it aside (see Chapter 1 if necessary).
8Turn the crankshaft until the small triangle
cast into the front edge of the crankshaft
sensor ring is aligned with the bottom edge of
the timing pointer located at the front of the
engine(see illustration).
9Look at the distributor rotor - it should be
pointing directly at the mark you made on the
distributor body. If so, you are at TDC for
number 1 cylinder.
10If the rotor is 180° off, the number one
piston is at TDC on the exhaust stroke.
11To get the piston to TDC on the
compression stroke, turn the crankshaft one
complete revolution (360°) clockwise. The
rotor should now be pointing at the mark
on the distributor. When the rotor is pointing
at the number one spark plug lead terminal in
the distributor cap and the ignition timing
marks are aligned, the number one piston is atTDC on the compression stroke. Note:If it’s
impossible to align the ignition timing marks
when the rotor is pointing at the mark on the
distributor body, the timing chain may have
jumped the teeth on the pulleys or may have
been installed incorrectly.
12After the number one piston has been
positioned at TDC on the compression stroke,
TDC for any of the remaining cylinders can be
located by turning the crankshaft and
following the firing order. Mark the remaining
spark plug lead terminal locations on the
distributor body just like you did for the
number one terminal, then number the marks
to correspond with the cylinder numbers. As
you turn the crankshaft, the rotor will also
turn. When it’s pointing directly at one of the
marks on the distributor, the piston for that
particular cylinder is at TDC on the
compression stroke.
4 Valve cover-
removal and refitting
1
Removal
1Disconnect the battery negative cable.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, makesure you have the correct activation code
before disconnecting the battery.
2Detach the PCV hose from the valve cover
(see illustration).
3Remove the spark plug leads from the
spark plugs, handling them by the boots and
not pulling on the wires.
4Remove the valve cover mounting screws,
then detach the valve cover and gasket from
the cylinder head. If the valve cover is stuck
to the cylinder head, bump the end with a
wood block and a hammer to jar it loose. If
that doesn’t work, try to slip a flexible putty
knife between the cylinder head and valve
cover to break the seal.
Caution: Don’t pry at the valve cover-to-
cylinder head joint or damage to the
sealing surfaces may occur, leading to oil
leaks after the valve cover is reinstalled.
Refitting
5The mating surfaces of the cylinder head
and valve cover must be clean when the valve
cover is installed. If there’s residue or oil on
the mating surfaces when the valve cover is
installed, oil leaks may develop.
6Apply RTV sealant around the two half-
circle rubber plugs at the rear of the cylinder
head (see illustration).
7Using a new gasket and spark plug tube
seals, refit the valve cover (see illustration).
Engine in-car repair procedures 2A•3
2A
4.6 Apply RTV sealant to the half-circle
plugs and insert them into the cylinder
head before refitting the valve cover4.7 Press the valve cover gasket into the
groove around the valve cover and fit a
new set of spark plug tube seals (arrowed)
3261 Jaguar XJ6 3.8 Align the mark on the crankshaft sensor ring (arrowed) with
the bottom edge of the pointer on the front cover
4.2 Disconnect the PCV hose (arrowed) from the valve cover, then
pull the spark plug leads out by their boots, not the leads

8Tighten the screws to the torque listed in
this Chapter’s Specifications in three or four
equal steps.
9Refit the remaining components, start the
engine and check for oil leaks.
5 Intake manifold-
removal and refitting
2
Removal
1Disconnect the negative cable from the
battery.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
2Refer to Chapter 4 to remove the
accelerator and cruise-control linkage, safely
relieve the fuel system pressure, and
disconnect the fuel supply lines.
3Label or mark and detach the PCV and
vacuum hoses connected to the intake
manifold, (see illustration).
4The intake manifold can be removed with
the injectors and fuel rail still in place.
Disconnect the electrical connectors at
each injector (label them first for reassembly).
If the injectors are to be removed from the
intake manifold, refer to Chapter 4.
5Refer to Chapter 4 and remove the throttle
body.6Remove the three nuts retaining the oil filler
tube bracket, then pull the tube up as far as
possible (see illustrations).
7Remove the ground strap and intake
manifold mounting nuts/bolts, then detach the
intake manifold from the engine (see
illustrations).
Refitting
8Clean the mating surfaces of the intake
manifold and the cylinder head mounting
surface with lacquer thinner or acetone. If the
gasket shows signs of leaking, have the
manifold checked for warpage at an
automotive machine workshop and
resurfaced if necessary.
9Refit a new gasket, then position the intake
manifold on the cylinder head and refit the
nuts/bolts (see illustration).
10Tighten the nuts/bolts in three or four
equal steps to the torque listed in this
Chapter’s Specifications. Work from the
centre out towards the ends to avoid warping
the manifold.
11Refit the remaining parts in the reverse
order of removal.
12Before starting the engine, check the
throttle linkage for smooth operation.
13Run the engine and check for coolant and
vacuum leaks.
14Road test the car and check for proper
operation of all accessories, including the
cruise control system.
6 Exhaust manifolds-
removal and refitting
2
Warning: The engine must be
completely cool before beginning
this procedure.
Removal
1Disconnect the negative cable from the
battery.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
2On 1990 and later models, disconnect the
EGR pipe and remove the EGR valve from the
top of the exhaust manifold (see Chapter 6).
3Apply penetrating oil to the exhaust
manifold mounting nuts/bolts, and the nuts
retaining the exhaust pipes to the manifolds.
After the nuts have soaked, remove the nuts
retaining the exhaust pipes to the manifolds
and the lower bolt from the heat shield (see
illustration).
4Remove the heat shield from the exhaust
manifolds(see illustration).
5Disconnect the electrical connector to the
oxygen sensor. Unless the oxygen sensor is
being renewed, leave the sensor in place.
6Remove the nuts/bolts and detach the
manifolds and gaskets (see illustration).
2A•4 Engine in-car repair procedures
5.3 The various hoses should be marked
to ensure correct refitting5.6a Remove the oil filler tube bracket
nuts (arrowed) . . .5.6b . . . pull the tube up to dislodge it
from the housing - it won’t come out, but
can be removed with the intake manifold
5.7a Remove the ground strap from the
front stud (arrowed), and the engine wiring
harness clips from the other studs5.7b Remove the intake manifold bolts/
nuts and remove the intake manifold - the
upper fasteners are studs/nuts, while the
lower row are bolts (two arrowed)5.9 Refit the new intake manifold gasket
over the studs (arrowed) refit the manifold
3261 Jaguar XJ6

damage the crankshaft in the process (if the
crankshaft is damaged, the new seal will end
up leaking).
9The crankshaft seal rides on a spacer that
slips over the front of the crankshaft. Slip the
spacer off and clean the varnish off the seal
surface (see illustration).
10Clean the bore in the cover and coat the
outer edge of the new seal with engine oil or
multi-purpose grease. Apply moly-base
grease to the seal lip.
11Lubricate the spacer with clean engine oil
and refit it onto the crankshaft. Using a socket
with an outside diameter slightly smaller than
the outside diameter of the seal, carefully
drive the new seal into place with a hammer
(see illustration). Make sure it’s installed
squarely and driven in to the same depth as
the original. If a socket isn’t available, a short
section of large-diameter pipe will also work.
Note:The new seal comes with a plastic
installer guide. Do not remove this guide until
refitting is completed. The guide keeps the
seal lip properly oriented over the crankshaft.
12Refit the Woodruff key, then refit the
damper. Tighten the damper bolt to the
torque listed in this Chapter’s Specifications.
Note:The damper bolt can be used to pull the
damper back onto the crankshaft, but make
sure the damper is perfectly aligned with the
Woodruff key.
13The rest of the assembly is the reverse of
the removal procedure.
14Run the engine and check for oil leaks at
the front seal.
8 Timing chains
and sprockets- removal,
inspection and refitting
3
Caution: If the timing chain broke during
engine operation, the valves may have
come in contact with the pistons, causingdamage. Check the valve clearance (see
Section 10) before removal of the cylinder
head - bent valves usually will have
excessive clearance, indicating damage
that will require machine workshop work to
repair.
Note 1:This procedure requires that the sump
be removed (see Section 12).In a professional
workshop, this would be performed as an in-
car procedure with specialised tools to
remove the front suspension. Given the
equipment available to the average home
mechanic, this alternate procedure requires
removal of the engine from the car.
Note 2:If your engine is a 4.0 litre, built after
serial number 9J160552, and you’re
experiencing an engine rattle on cold starts
that disappears after the engine is warmed up,
the problem could be a defective upper
tensioner. A newly designed replacement
upper tensioner is available from the dealer
and should solve the problem. It can be
installed easily without pulling the cylinder
head or front cover, or can be installed during
a chain removal procedure.
Removal
1Disconnect the negative cable from the
battery.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
2Block the rear wheels and set the
handbrake.
3Refer to Part B of this Chapter for engine
removal procedures.
4Refer to Section 4 and remove the valve
cover.
5Refer to Section 3 and position the engine
at TDC for cylinder number 1, then mark and
remove the distributor (see Chapter 5).
6Refer to Section 11 and remove the cylinder
head. After cylinder head removal, the uppertiming chain will be loosely retained by the
two upper chain guides, which are retained by
refitting a large rubber band (see Section 10).
Caution: Do not rotate the crankshaft with
the upper timing chain disconnected and
the cylinder head and camshafts in place,
or damage could result from piston-to-
valve contact.
7Some models may be equipped with a
hydraulic pump used for the brake
servo/hydraulic self-levelling suspension
system. If equipped, it will be mounted to the
front cover. Models not equipped with this
option will have a flat block-off plate over the
hole. If equipped with the pump, refer to
Chapters 9 and 10 for procedures to reduce
the high pressure in the brake servo system
and to depressurise the self-levelling system.
Before removing the engine, unbolt the pump
from the front cover and set it aside without
disconnecting the hoses (see illustration).
8Refer to Section 7 and remove the
crankshaft pulley and damper. Refer to
Section 12 for removal of the sump.
9If equipped with the hydraulic pump,
remove the coupling disc and unbolt the drive
coupling from the intermediate shaft (see
illustrations).
2A•6 Engine in-car repair procedures
8.7 Unbolt the hydraulic pump (arrowed)
from the front cover, without
disconnecting the hoses
3261 Jaguar XJ6 7.9 Remove the spacer from the end of the crankshaft
and clean it thoroughly
7.11 Drive the new seal squarely into the front cover with a large
socket or section of pipe - do not remove the plastic refitting
guide (arrowed) until the seal is installed

Refitting
23If the valve clearance for any valve is
incorrect, as measured in paragraph 4, refit a
thicker or thinner shim on that valve. For
example, if the clearance had been too large
by 0.004-inch (compared to the recommended
clearance in the Specifications), replace the
existing shim there with a new one that is
0.004-inch thicker. If the clearance was too
small, use a shim that is smaller than the
original. Shims are identified alphabetically, in
sizes from 0.085-inch (designated size A, the
smallest) to 0.108-inch (designated size X, the
thickest).
24Lubricate the lifters with a thin coat of
moly-based lubricant on the top, bottom and
sides and refit them in their original positions.
25Lubricate the camshafts with moly-based
grease on the journals and lobes and lay them
carefully in their bearing saddles.
26Using NEW cylinder head bolts, replace
the spacers, one at a time, with the bearing
caps and bolts. Tighten the cap bolts, then
the cylinder head bolts to the torque listed in
this Chapter’s Specifications. The front capshould be installed first, then cap number 7,
then alternately tighten the first and last caps
to bring the camshaft down evenly. Next refit
caps 4, 2, 3, 5, and 6.
27Align the intake camshaft with the special
camshaft positioning tool as described in
paragraph 5. Engage the outer sprocket with
the chain, slip the sprocket over the end of the
camshaft, then turn it until there is no slack in
the chain to the right of the camshaft sprocket
(facing the front of the engine). Now align the
inner sprocket with the camshaft until the bolt
holes align and mesh the splines between the
two sprocket halves (see illustrations).
Tighten the inner sprocket bolts to the
camshaft and bend the locking sheetmetal
tabs over the bolts.
28Keeping the slack in the chain to the left
of the exhaust camshaft, refit the exhaust
camshaft outer sprocket, meshed with the
chain, over the end of the exhaust camshaft.
Insert the timing chain tensioner tool (Jaguar
tool no. 18G 1436) at the upper tensioner
mounting point (see illustration). Note:The
chain tensioner tool applies pressure to the
upper timing chain to simulate the effect of thetensioner, which is operated by engine oil
pressure when the engine is running.
29Align the exhaust camshaft to TDC with
the special timing gauge tool. Tighten the
centre bolt in the tensioner tool to 4 to 6 Nm.
When the chain is tensioned, align the inner
exhaust sprocket with the bolt holes in the
camshaft, engage the splines between the
two sprocket halves and secure the sprocket
with the bolts and locking tabs. Refit the clip
to secure the two sprocket halves together.
30Clean the tensioner gasket surface, fit a
new gasket and O-rings, push the ratchet
down and twist it to maintain the fully
retracted position, and refit the tensioner in
place of the tensioning tool (see illustration).
Note:Align the slot in the end of the tensioner
straight up and down to fit over the tang on
the back of the chain tensioner guide.
31Rotate the engine and recheck that all
valve clearance measurements are now
correct (see paragraph 4).
32The remainder of refitting is the reverse of
the removal procedure. Note:When refitting
the distributor, use a new O-ring where it fits
into the engine block.
2A•12 Engine in-car repair procedures
3261 Jaguar XJ6 10.27a Each camshaft sprocket is comprised of two sections, an
inner (A) and outer (B) that are splined together
10.27b Push the outer sprocket over the intake camshaft until it
locks in place - then turn the sprocket left to remove chain slack
at the right
10.28 The special tensioning tool simulates the operation of the
oil-driven tensioner - apply 4 to 6 Nm (36 to 48 inch-pounds)
pressure on the centre bolt (arrowed)10.30 Upper timing chain tension components
A Notch (to align
with tang on guide)B Tensioner ratchet
C O-ringD Gasket
E valve (with O-rings)

Refitting
5Remove all traces of old gasket material
and sealant from the engine block and sump.
Clean the mating surface with lacquer thinner
or acetone.
Caution: Do not use a sharp scraping tool.
Both the sump and the engine block are
aluminium and could be easily damaged.
6Make sure the threaded bolt holes in the
engine block and bellhousing are clean.
7Inspect the flange of the sump for any
cracks, pits or scratches that could cause an
oil leak.
8Remove the baffle plate at the rear of the
sump (see illustration). Clean the sump area
and the baffle, then refit the baffle.
9Inspect the oil pump pickup tube for
cracks, or foreign material blocking the screen
(see illustration).
10Apply a bead of RTV sealant to the sump
flange(see illustration). Note:The sump
must be installed within 5 minutes of sealer
application.
11Carefully position the sump on the engine
block and push it toward the transmission
adapter plate as you press it against the
engine block. Loosely refit four bolts, two on
each side of the sump. Tighten the four bolts
in a criss-cross pattern to the torque listed in
this Chapter’s Specifications, then loosen
each bolt 90°.
12Refit the two engine adapter-to-sump
bolts. Tighten the two bolts to the torque
listed in this Chapter’s Specifications, then
loosen each one 180°.
13Refit the remainder of the sump-to-engine
block bolts hand tight until all are installed,
then tighten them to the torque listed in this
Chapter’s Specifications. Lastly, tighten the
two adapter-to-sump bolts to the torque
listed in this Chapter’s Specifications.
Caution: Failure to follow this tightening
procedure could stress or possibly crack
the adapter plate.
14The remainder of refitting is the reverse of
removal. Be sure to add oil and refit a new oil
filter.
15Run the engine and check for oil pressure
and leaks.13 Oil pump- removal,
inspection and refitting
4
Removal
1Remove the sump (see Section 12).
2Unbolt the oil pickup tube and oil transfer
housing from the engine block (see
illustration). Note:Have a drain pan under the
transfer housing, as oil may drip out when the
housing is loosened from the engine block.
3Carefully pull the transfer housing and
transfer tubes to the rear to separate them
from the oil pump body.
4Bend back the locking tabs and remove thethree bolts retaining the oil pump drive
sprocket to the oil pump (see illustration).
Pull the chain and sprocket from the front of
the pump. Note:There are shims between the
sprocket and the pump. Collect them while
pulling off the sprocket.
5Remove the bolts and detach the oil pump
from the engine.
6Remove all traces of sealant and old gasket
material from the oil pump body and engine
block, then clean the mating surfaces with
lacquer thinner or acetone.
7Remove the screws and separate the front
and rear pump covers from the body. Lift out
the drive and driven rotors (see illustrations).
Note:Mark the front face of each rotor before
removing them.
Engine in-car repair procedures 2A•15
2A
12.8 Remove the bolts (arrowed) and the
sheetmetal baffle plate - clean the sump
area of the sump with the baffle removed12.9 Lubrication system components
A Oil pump
B Transfer tubesC Transfer housing
D Oil pump pickup12.10 Apply a bead of RTV sealant around
the perimeter of the sump mounting
flange, be sure to run the bead around the
outside all bolt the holes
13.7a Remove the bolts and separate the
front and rear pump covers13.7b Remove the outer rotor (A)
and inner rotor (B)
13.2 Unbolt the oil pump pickup (A) and
the bolts (B) retaining the transfer
assembly (C) to the engine block13.4 Pry back the locking tabs and remove
the three bolts retaining the oil pump drive
sprocket to the pump
3261 Jaguar XJ6

Inspection
8Clean and dry the pump body and both
rotors. Measure the outside diameter of the
outer rotor and thickness of both rotors.
9Place the outer rotor into the pump body
and use feeler gauges to measure the
clearance between the outer rotor and the
body (see illustration).
10Place a straightedge across the pump
body and measure between the straightedge
and the rotors to check the over-the-rotor
clearance (see illustration). Compare your
measurements to this Chapter’s Specifications
and renew the oil pump if any are beyond the
maximum allowable.
11Remove the oil pressure relief valve cap.
Remove and clean the relief valve components
(see illustration).
12Clean all components with solvent and
inspect them for wear and damage. If
excessive wear, damage or if any clearance is
beyond the Specifications, renew the entire
pump as an assembly.
13Check the oil pressure relief valve piston
sliding surface and valve spring. If either the
spring or the valve is damaged, they must be
renewed as a set.
Refitting
14Lubricate the drive and driven rotors with
clean engine oil and place them in the casewith the marks facing out. Apply a thin coat
of anaerobic sealant (Loctite 510 or 518) to
the gasket flange and refit the cover (see
illustration).
15Lubricate the oil pressure relief valve
piston with clean engine oil and refit the valve
components into the oil pump body (see
illustration 13.11).
16Apply a thin coat of anaerobic sealant
(Loctite 510 or 518) to the oil pump-to-engine
block-mounting surface, position the oil pump
body against the engine block and refit the
mounting bolts, tightening the bolts to the
torque listed in this Chapter’s Specifications.
Follow a criss-cross pattern when tightening
the bolts to avoid warping the oil pump body.
17If using the original oil pump, refit the
original sprocket shim pack (see illustration).
If a new pump is installed, start off with a
0.38 mm (0.015-inch) thick shim pack, refit the
drive sprocket and align the sprocket as
follows.
18Use a straightedge to check the alignment
of the oil pump sprocket with the crankshaft
sprocket (see illustration). If they are not
aligned, increase or decrease the shim pack at
the oil pump sprocket until alignment is correct,
then secure the oil pump sprocket bolts by
bending up the sheetmetal tabs. Note:You
may be able to use all or part of the original
shim pack from the original oil pump (if a new
pump is being fitted). If required, shims areavailable in 0.127 mm (0.005 inch), 0.254 mm
(0.010 inch) and 0.508 mm (0.020 inch) sizes.
19Fit new O-rings to each end of the transfer
tubes and refit the tubes into the transfer
housing. Note:Use petroleum jelly to lubricate
the O-rings.
20Apply a thin coat of RTV sealant to the
engine block-mounting surface of the transfer
housing. Lift the transfer housing and tubes
into place and push the front of the tubes
in the back of the oil pump, until you can start
the transfer housing-to-engine block bolts.
Tighten the bolts to the torque listed in this
Chapter’s Specifications.
21Refit the remaining parts in the reverse
order of removal.
22Add oil, start the engine and check for oil
pressure and leaks.
23Recheck the engine oil level.
14 Driveplate-
removal and refitting
4
Removal
1Raise the car and support it securely on
axle stands, then refer to Chapter 7 and
remove the transmission. If it’s leaking, now
would be a very good time to renew the front
pump seal/O-ring.
2A•16 Engine in-car repair procedures
13.9 Measure the outer rotor-to-body
clearance with feeler gauges (arrowed)13.10 With a straightedge held tight to the
pump surface, measure the clearance over
the rotors with feeler gauges13.11 Oil pressure relief valve components
A Relief valve cap
B TubeC Spring
D Valve
13.14 Apply a thin coat anaerobic sealant
(Loctite 510 or 518) to the pump cover
sealing surface
13.17 Refit the original shim pack
(arrowed) if the original pump is being
used - if a new pump is being installed,
refit a 0.38 mm (0.015-inch) shim pack
3261 Jaguar XJ6
13.18 Check the oil pump and crankshaft
sprocket alignment with a straightedge -
add or subtract shims until the sprockets
are aligned for smooth chain operation

3261 Jaguar XJ6
2B
Chapter 2 Part B
Engine removal and overhaul procedures
General
Cylinder compression pressure @ 300 rpm, warm
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6 to 11.3 bar (150 to 160 psi)
High compression models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 to 12.1 bar (160 to 170 psi)
Maximum variation between cylinders . . . . . . . . . . . . . . . . . . . . . . . . 0.8 bar (10 psi)
Oil pressure (engine warm)
At idle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 bar (30 psi) minimum
At 4000 rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9 bar (70 psi) minimum
Cylinder head
Resurfacing limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.25 mm (0.010 inch) maximum
Minimum thickness (see text)
3.6 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129.6 mm (5.101 inches)
3.2 and 4.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129.7 mm (5.108 inches)
Valves and related components
Valve stem-to-guide clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.038 to 0.076 mm (0.0015 to 0.0030 inch)
Valve springs, free length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40.13 mm (1.580 inches)
Valve lifter
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.34 to 33.35 mm (1.3126 to 1.3130 inches)
Lifter-to-bore clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02 to 0.05 mm (0.0008 to 0.0020 inch)
Crankshaft and connecting rods
Connecting rod journal
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52.97 to 52.99 mm (2.0856 to 2.0861 inches)
Taper and out-of-round limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.008 mm (0.0003 inch) maximum
Bearing oil clearance
3.6 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.083 mm (0.0016 to 0.0033 inch)
3.2 and 4.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 to 0.0068 mm (0.0010 to 0.0027 inch)
Connecting rod side clearance (endplay) . . . . . . . . . . . . . . . . . . . . . . . . 0.127 to 0.228 mm (0.005 to 0.009 inch)
Main bearing journal
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76.217 to 76.233 mm (3.0007 to 3.0012 inches)
Taper and out-of-round limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.008 mm (0.0003 inch) maximum
Bearing oil clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.083 mm (0.0016 to 0.0033 inch)
Crankshaft endplay (standard) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.101 to 0.254 mm (0.004 to 0.010 inch) CHECK ENGINE light . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6
Crankshaft - inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Crankshaft - refitting and main bearing oil clearance check . . . . . . . 23
Crankshaft - removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Cylinder head - cleaning and inspection . . . . . . . . . . . . . . . . . . . . . . 10
Cylinder head - dismantling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Cylinder head - reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Cylinder compression check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Cylinder honing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Engine block - cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Engine block - inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Engine overhaul - dismantling sequence . . . . . . . . . . . . . . . . . . . . . . 8
Engine overhaul - general information . . . . . . . . . . . . . . . . . . . . . . . . 2
Engine overhaul - reassembly sequence . . . . . . . . . . . . . . . . . . . . . . 21Engine rebuilding alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Engine - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Engine removal - methods and precautions . . . . . . . . . . . . . . . . . . . 5
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Initial start-up and running-in after overhaul . . . . . . . . . . . . . . . . . . . 26
Main and connecting big-end bearings - inspection and selection . 20
Pistons/connecting rods - inspection . . . . . . . . . . . . . . . . . . . . . . . . 18
Pistons/connecting rods - refitting and big-end bearing
oil clearance check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Pistons/connecting rods - removal . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Piston rings - refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Rear main oil seal refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Vacuum gauge diagnostic checks . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Valves - servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2B•1
Specifications Contents
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321

Engine block
Deck warpage limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.076 mm (0.003 inch)
Cylinder bore diameter
Standard
Size group A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90.990 to 91.003 mm (3.5823 to 3.5828 inches)
Size group B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.005 to 91.018 mm (3.5829 to 3.5834 inches)
Oversize
0.25 mm (0.010 inch) OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.259 to 91.272 mm (3.5929 to 3.5934 inches)
0.50 mm (0.020 inch) OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.513 to 91.526 mm (3.6029 to 3.6034 inches)
Pistons and rings
Piston-to-bore clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.017 to 0.043 mm (0.0007 to 0.0017 inch)
Piston ring end gap
No.1 (top) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 to 0.66 mm (0.016 to 0.026 inch)
No.2 (middle) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 to 0.66 mm (0.016 to 0.026 inch)
Oil ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.30 to 0.55 mm (0.012 to 0.022 inch)
Piston ring groove clearance
No. 1 (top) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.076 mm (0.0016 to 0.0030 inch)
No. 2 (middle) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.076 mm (0.0016 to 0.0030 inch)
Torque wrench settingsNm lbf ft
Main bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 to 142 100 to 105
Connecting rod cap nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 to 60 37 to 44
* Note:Refer to Part A for additional torque specifications.
2B•2 Engine removal and overhaul procedures
3261 Jaguar XJ6
1 General information
Included in this portion of Chapter 2 are the
general overhaul procedures for the cylinder
head and internal engine components.
The information ranges from advice
concerning preparation for an overhaul and
the purchase of replacement parts to detailed,
step-by-step procedures covering removal
and refitting of internal engine components
and the inspection of parts.
The following Sections have been written
based on the assumption that the engine has
been removed from the vehicle. For
information concerning in-vehicle engine
repair, as well as removal and refitting of the
external components necessary for the
overhaul, see Part A of this Chapter.
The Specifications included in this Part are
only those necessary for the inspection and
overhaul procedures which follow. Refer to
Part A for additional Specifications.
2 Engine overhaul-
general information
It’s not always easy to determine when, or if,
an engine should be completely overhauled,
as a number of factors must be considered.
High mileage is not necessarily an indication
that an overhaul is needed, while low mileage
doesn’t preclude the need for an overhaul.
Frequency of servicing is probably the most
important consideration. An engine that’s had
regular and frequent oil and filter changes, as
well as other required maintenance, will most
likely give many thousands of miles of reliableservice. Conversely, a neglected engine may
require an overhaul very early in its life.
Excessive oil consumption is an indication
that piston rings, valve seals and/or valve
guides are in need of attention. Make sure that
oil leaks aren’t responsible before deciding
that the rings and/or guides are bad. Perform a
cylinder compression check to determine the
extent of the work required (see Section 4).
Also check the vacuum readings under various
conditions (see Section 3).
Check the oil pressure with a gauge
installed in place of the oil pressure sender
unit (see illustrations)and compare it to this
Chapter’s Specifications. If it’s extremely low,
the bearings and/or oil pump are probably
worn out.
Loss of power, rough running, knocking or
metallic engine noises, excessive valve train
noise and high fuel consumption rates may
also point to the need for an overhaul,
especially if they’re all present at the same
time. If a complete tune-up doesn’t remedy
the situation, major mechanical work is the
only solution.An engine overhaul involves restoring the
internal parts to the specifications of a new
engine. During an overhaul, the piston rings
are replaced and the cylinder walls are
reconditioned (rebored and/or honed). If a
rebore is done by an automotive machine
workshop, new oversize pistons will also be
installed. The main bearings, big-end bearings
and camshaft bearings are generally replaced
with new ones and, if necessary, the
crankshaft may be reground to restore the
journals. Generally, the valves are serviced as
well, since they’re usually in less-than-perfect
condition at this point. While the engine is
being overhauled, other components, such as
the distributor, starter and alternator, can be
rebuilt as well. The end result should be a like
new engine that will give many trouble free
miles. Note:Critical cooling system
components such as the hoses, drivebelts,
thermostat and water pump should be
replaced with new parts when an engine is
overhauled. The radiator should be checked
carefully to ensure that it isn’t clogged or
leaking (see Chapter 3).If you purchase a
2.4a The oil pressure sender unit (arrowed)
is located in the right front corner of the
engine block, near the oil filter2.4b The oil pressure can be checked by
removing the sender unit and refitting a
pressure gauge in its place