Jaguar
Page 2
Name: Winston
Subject: loud noise on exhaust side of head
Question: '86 XJ6 - Is this a sign of not having a stakedown kit? Can you
refer me to anyone in the Kansas City area that knows Jaguars? I have had no
luck...
Answer: Hi Winston,
If it is a clicking noise it is possible that it needs the kit installed. I
would not run the engine any at all until you either check it yourself or have
it checked. It is not hard to check it. If you want to do it yourself, let me
know and I will walk you through it.
I don't have any contacts in Kansas City but I would have thought that there
is a Jag dealer there.
Google says this is a Jag dealer but you need to call first to see if it is a
Jag dealership or just a used car lot that sells Jags.
Aristocrat Motors
9400 W 65th St
Shawnee, KS 66203
(913) 677-3300
My advise is to pull that side cover to see if it is needing a hold down kit
or just loose valve clearance. Or both.
The sleeves are soft and if they are coming out to where the cam is cutting
them away, sometimes they can be forced back into the head and just install
the hold down kit without replacing them. If any are too far out and pieces
broken off then the head will need to be removed and a machine shop will have
to do the job. If the cam has just warn away edges I have on many occasions
just heated the head area and drove them back in and installed a kit to keep
them down. Sometimes the sleeve is damaged trying to drive it back in and the
machine work is than still necessary. Some dealerships because of the
liability will not even try to force them back in and will require the head
removal and machine work, so keep that in mind. Do not let anyone talk you
into just installing the kit without fully seating the sleeves.
Good luck, let me know how you do.
Howard
Name: Arjun
Subject: XJ12 idle problem
Question: Dear William Brady and/or Howard M. Fitzcharles
I would be most grateful if you could review and answer a question for me
regarding a 1987 XJ12.
When started and allowed to idle the first 20 to 40 seconds is uneventful and
the engine runs just fine and sits at 750 RPM as should be the case according
to the emissions sticker. About 40 seconds into the engines operation the
solenoid air valve (right side air filter housing) kicks in increasing the
engines RPM to an unacceptable 1200 RPM. In addition to this high idle a
slight oscillation begins to occur, first varying 50 or 60 RPM and gradually
getting worse to the point where the engine idle fluctuates between high and
low points of 300 RPM to 1400 RPM respectively.
At 300 RPM the engine has difficulty running, sounding like it is on its last
stroke before stalling out and than all of a sudden springing back to life
shooting right up to 1400 RPM where once again, after residing there for less
than a fraction of a second, falls back to 300 rpm. This cycle continues until
I decide to shift the vehicle into drive or reverse.
When shifted into drive or reverse the oscillatory idle still exists, however
only to a very negligible extent. When shifted into gear, engine idle
oscillates between 700 and 800 RPM. My guess is that this is because the
problem causing the oscillation; becomes damped out when a load is placed on
the engine.
I should also mention that the oscillation does not follow through when
accelerating or driving the car. The vehicle accelerates and drives
flawlessly. Idle problem returns gradually when stopped at a light or
intersection for any appreciable amount of time.
In the parked state of the vehicle, the oscillation completely disappears as
throttle is increased causing rise in engine rpm. Relieving the throttle and
allowing the engine to return to idle is when the oscillation will again
reappear as such.
I have checked all the following and have deemed them to be proper working
condition.
• Auxiliary air valve (replaced with used one that works)
• Solenoid air valve at air filter housing
• Both left and right over run valves.
• Dump valve
• Distributor vacuum capsule
• Ignition timing properly set according to emission sticker (18 degrees
BTDC @ 3000 RPM)
• Left and right throttle plates have proper clearance according to
emission sticker. (0.0025 inches)
• No vacuum leaks were detected; search was thoroughly conducted and is
on going to no avail.
• Throttle position sensor reads .62 volts at closed position and around
4.90 volts at full open position.
• Throttle position switch read continuity when throttle pulley triggers
it
• Left and right O2 sensors bench tested using home mechanic method of
connecting voltmeter and reading voltage when heated with a butane torch. Both
sensors read 0.90 volts when flame tip applied and 0 volts when flame tip was
removed.
• Coolant temperature sensor read correct resistance through out
temperature range of operation. (There existed a small discrepancy of what
Jaguar Service Manual suggested. At 100 degrees Celsius book value of 190
ohms, measured value of 240 ohms, discrepancy followed through on measured
resistance from 100 to 18 degrees Celsius)
• Air temperature sensor
• Fuel Pressure read approximately 45 PSI at idle and maintained this
pressure as engine was revved.
I did notice one peculiar result when disconnecting and plugging the computers
MAP sensor at the manifold cross over pipe that connects left and right intake
manifolds. (Exhaust fumes became incredibly noxious with the smell of unburned
gasoline fumes, accompanied by this was a rougher idle that no longer
oscillated up and down as described.)
Weather this is just assigning blame to a component as a result of an
unrelated cause and effect or if it is in fact the sub system at fault; I am
unsure. Only wanted to state as a simple observation I made as to provide the
most information possible, in ascertaining the true cause.
Any advice to possible avenues I may have not investigated or possible
culprits to this elusive problem would be greatly appreciated.
A most sincere thank you for taking the time to read my post, it is
appreciated.
Regards Arjun Sinha
Answer: Hi Arjun,
Your elaborate symptoms don't tell me what is wrong but if I were faced with
all that, I would use some basic facts to help find such a problem. If you
don't have a scope and CO equipment, do this.
Warm the engine up first, then put a volt meter on an O2 sensor while it is in
it's high oscillations and read what the 02 voltage is. Check both. A .5v
reading would be a normal reading if the mixture were correct. High readings
are a rich mixture and low readings would be a lean mixture.
If you have any gasoline engine at idle there are only a few things that can
make it go faster. Lean out the mixture, advance the timing and / or allow air
to enter the intake manifold.
When it is in the high oscillating mode start pinching off vacuum lines and
block off the Aux air valve. Don't forget the brake booster. An engine can't
go from 300 RPM to 1400 RPM without additional air.
Also, your injection coolant temp sensor is a major influence on mixture at
all speeds.
If your 02 voltage indicates lean, try disconnecting them when it is in the
high oscillation mode. If they indicate lean, try spraying something like WD
40 into the intakes when it is in the high oscillating mode.
When the engine is warmed up and at idle pinch off the vacuum to the fuel
pressure regulator. If the RPM increases the fuel mixture is too lean and if
it slows down it is too rich. (unlikely)
Let me know,
Howard
Name: DAVE
Subject: Cruise Control 1986 Series 3
Question: Hello Howard,Iwondered if you could help me before I need to take my
Jag into a srevice agent.The cruise control has just stopped working,checked
all main fuses,unless there is a hidden one some where,it is the last of the
series 3 1986 new New Zealand done 30.000 miles.
Answer: Hi Dave,
Two fuses are used, one is the fuse #11 in the main fuse box which operates
the brake lights. The other is fuse #12 in the main fuse box.
Two brake switches are used, the brake light switch (lever type) and a smaller
push switch. The other switches used are the master switch on the rear of the
shift console and an inhibit switch inside on the shift mechanism. A set
switch is on the turn signal lever. The ECU is mounted near the secondary fuse
panel. The signal comes to the ECU form the speedometer pulse generator by a
yellow wire to the ECU plug. Also confirm that you have vacuum at the
actuator.
Howard
Name: Mike
Subject: Positive Ground
Question: Can you tell me which jaguars models (by year) used positive battery
ground?
Answer: HI Mike,
All Jaguars, XK-120, XK-140, XK150 and the early E-type were positive ground.
As I remember, the first negative ground cars were the cars using an
alternator. I think the same was true in the sedans. The generator cars could
be switched as I had to switch many over the years for various reasons. If you
want to switch one, read my section on "Tech Tips" on my web site,
http://mg-tri-jag.net.
Howard
Name: Wayne
Subject: 1989 xj12 sovereign
Question: Hi Howard I'm the new owner of the above car .My speedo went on me
the other day ,and I'm told i need a transducer.Where do i locate it on the
car ,and can i do it myself.Regards Wayne Roberts
Answer: Hi Wayne,
If the transducer is bad and that is one of the components of the speedometer
system. It is an electrical component mounted on the side of the transmission.
If the transducer is not working or not connected you will also have lost your
operation of the trip computer and cruise control.
I have no experience nor info on Jaguar past the 1987 XJ-6 but I would guess
the 89 XJ-12 speedo system is the same.
Howard