Here are some quick remarks on some of
the more common repair issues and questions. Most of these items pertain
to the Series I-II-III XJ Saloons but you XJ-S owners may find some useful
tips, too.
Wipers don't self-park
The fault here almost always lies with the column mounted control switch
and not with the "park switch" on the wiper motor. (Ser III)
Clunk, rattle,
crunch noise over bumps
The upper bushings for the front shocks are almost always disintegrated
on these cars, allowing the shock to rattle against the inner fenderwell.
New replacement bushings are available separately and many owners have
successfully used generic bushings from a local parts supply. Also check
the braces which run diagonally from the cowl to the fenders (wings).
Make sure they are tight......very tight. Anything thing less will allow
them to makes noise as the body flexes.
Power door
locks inoperative or slow working
In about 80% of the cases the recalcitrant locks can be brought back to
life by removing the door trims and thoroughly lubricating all the linkages
and sliding points. Use an aerosol lubricant, silicone spray works well.
(Ser II and III)
Vibration
felt when brakes applied
This is usually caused by warped brake rotors. Rotors can often be taken
to a machine shop and be resurfaced but most owners replace them with
new ones. The new ones are not too expensive and, since the job is labor-intensive,
it makes sense to just install new ones.
Speedometer
inoperative or erratic
In about mid-1982 or so (for North American market cars, later for rest-of-world)
Jaguar switched from a cable-operated instrument to an electric one. A
transmission-mounted transducer produces a signal which is sent to the
speedometer. This transducer is the most common culprit when you speedo
acts up or just plain quits. Of course the connections should be checked
first. (SerIII)
Cruise control
does not work
There are many possibilities here but often the fix is easy. First, check
the 2-amp fuse (#12 fuse, main fuse box). Next check the vacuum bellows.
This often leaks at the edges and can be cleaned and resealed with silicone
sealer. Don¹t forget to check the vacuum supply to the bellows. The
hose may have perished with age. (SeriesIII)
Engine will
not crank
Assuming the battery is good, here are a couple of quick checks. Examine
the battery cables/terminals for cleanliness and tightness. Ditto for
the two firewall-mounted junction posts. Also try tapping the starter
relay (firewall mounted, silver, oblong). If tapping the relay brings
the starter back to life then replace the relay or disassemble it and
clean the contacts.
Power antenna
won¹t retract all the way
Examine the mast for slight bends and gently reshape by hand, if needed.
Thoroughly clean the mast and lubricate it with an aerosol lube (silicone,
graphite, etc). In nearly all cases this is all that's required. (Series
II and III)
What is normal
engine temperature?
Normal operating temperature is 88C-90C degrees. This is the beginning
of the green band on the temperature gauge (SeriesIII 6-cylindercars).
If the cooling system is in good order you should have no problem staying
at the 88C-90C range unless you are in extreme conditions, i.e.: bumper-to-bumper
traffic and/or ambient temps of 90-100F degrees. The auxiliary electric
fan will come on at about 95C degrees. In high ambient temps I would say
that anything over 100C degrees is cause for concern. In cooler temps,
anything over 90C merits investigation.
Identification
of sensors on the water rail
On the fuel injected 6-cylinder cars, here's what the different sensors
are and what they do, starting from the front position. First is the Thermotime
Switch. This is a heated switch. It controls the cold start injector.
This switch operates only when the starter is engaged and only when the
engine is cold. Next is the sending unit for the dashboard mounted temperature
gauge. Next is the fuel injection coolant temp sensor, which sends a signal
to the boot-mounted ECU (Electronic Control Unit). This sensor is an important
part of the fuel metering system. Rearmost is the temperature switch for
the air injection pump and the canister purge system. On some non-North
American and/or SeriesII cars this sender is replaced by a vacuum switch
for the EGR-equipped cars.
Identification
of firewall relays
On 6-cylinder fuel injected cars, starting from the right (viewed from
driver's seat) you have: The all-red Diode Pack. This is not actually
a relay. It has several diodes inside and directs the flow of voltage
in the fuel pump circuit. Next is the fuel pump relay. Next is the "main"
relay, which feeds the injector ballast and a portion of the fuel pump
circuit. Furthest inboard is the silver starter relay. Note: The location
of the fuel pump and main relays can be inadvertently reversed. The fuel
pump relay is easily identified by the white/green wires, which are not
there on the main relay. Incidentally, the 6-cylinder cars do not have
a "cold start" relay. The repair manual is confusing in this
regard. The SeriesII XJ6's with fuel injection have a large, single, combination
relay in place of the diode pack, main relay, and fuel relay. This combination
relay was also used on a few of the very earliest SeriesIII cars.
Power windows
inoperative
In a great many instances the cause is dirty contacts inside the window
switches. On SerII and III cars (perhaps Series I, too. Not sure...) the
switches can be easily accesses by removing the console cubby box and
releasing the switches from the rear by depressing the retaining tabs.
The switches can be removed, then, from the front. Do one at a time to
avoid mixing up the wiring. A good aerosol contact cleaner (i.e., from
Radio Shack) can be squirted into the switches through the small holes
in the sides. Or, many owners have reported that the switches are relatively
easy to disassemble and the contacts can then be easily cleaned with a
pencil eraser.
Tires
Hours could be spent on the very subjective topic of tires. All owners
agree that a high quality tire is called for. Jaguar specifies a "V-rated"
tire for the XJ sedans and the many owners insist that this recommendation
be adhered to. The V-rated tires, generally speaking, have stronger casings
and sidewalls. It must be stated, however, that many owners have been
perfectly happy with more ordinary S-T- or H-rated tires. The Series I
and II cars used a 205/70x15 or ER70x15. The early SeriesIII cars also
used a 205/70x15. However, about mid-way through the SeriesIII production
a 215/70x15 became standard issue on North American spec cars. All V12
SeriesIII's used the 215/70 tire.
Interior lights
inoperative from door switches
A few shots with your aerosol electrical contact cleaner will almost always
bring recalcitrant door jamb switches back to life.
Erratic headlamp
operation
In most cases the fuses (in under-bonnet fuse box ) are dirty, loose,
or corroded. Easy fix. Replace the fuses or at least clean the end caps.
Gently clean the fuse clips and, if the fuse is a loose fit, carefully
bend the clips to restore a snug fit.
Wheel alignment
Front wheel alignment on a XJ sedan is no more difficult than any other
"ordinary" car, and, in fact, is easier than many. Jaguar specified
that special links be used to compress the suspension to simulate a laden
condition. Since our Jags are seldom driven fully laden, this step is
not necessarily needed. The Jaguar adjustment shims are a bit unique but
just about any alignment specialist will have something suitable as a
replacement. Alignment of the rear wheels is limited to the camber adjustment
only. It is a labor-intensive job and seldom required.
Automatic
transmission fluid
Looked in your manuals and wondering what "Type G" fluid is?
You're not alone. It is an obsolete designation. If you have a Borg-Warner
transmission (all 6-cylinder cars, V12's up to about 1978 or so) the correct
replacement is "TypeF" or "Type FA", both readily
available. Some owners use Dexron and report a softer shift with no problems.(
If you have a 12 cylinder car with the General Motors TH400 transmission
the correct fluid is Dexron and only Dexron.)
Electrical
gremlins
The horror stories are highly exaggerated. In many cases the problem is
not a faulty component but, instead, a faulty fuse and/or dirty, loose
connectors. If your Jag develops an electrical glitch, always start by
checking fuses and connectors. Always ! Don't assume a fuse is good just
because it looks OK. Test it or replace it to be sure.
Shock absorbers
Shocks are available from Koni, Monroe, Bilstein, KYB, Woodhead, etc.
However, the vast majority of owners seem to prefer and recommend the
Boge brand. Boge was the OEM supplier for many years.
Cold water
slosh on turns
When using your air conditioner it is normal for condensation to develop.
The evaporator case has drains to let the condensate escape. These drains
often clog and the result is cold, brackish water pooling in the case.
It sloshes out on turns. With the car safely elevated the drains can be
cleared by probing them with a piece of stiff wire. The two drain tubes
can been seen existed the floorboards on either side of the transmission
tunnel, just aft of where the engine and transmission come together.
posted: 8/16/2002
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