[xj] Problems with the transmission and cooling system

Ville_Lausmae · March 18, 2001, 7:45pm

Hi,
I was wondering if anyone here could give me some good advice on the
little “or not so little” problems with my car.
The seriousness of the problems (or the cost of repairing them) is
unknown to me because I can’t appear to find a source for the problems.

The story goes like this.
I’ve had the car for about three years. When I bought it it was
something that could be called a wreck. During these years I have spent
quite a bit of time in the garage repairing, cleaning, fixing and
generally fiddling around with the car. In the summertime (3-5 months
here) I used the car as a daily driver, during that time it never
developed any new problems. Until last autumn when I replaced the vacuum
diaphragm and got the engine nicely going. Well after changing the
vacuum diaphragm and getting the car running nicely I made quite many
speeding experiments (during one I lost my drivers license ). And
suddenly problems started to pop up. I stored the car for the winter and
decided to forget all about it for a while. But now the summer is
approaching and I’d like to fix the car to be able to use it again and
feel the enjoyment of having a Jag :).

Well one of the problems was that the transmission started acting funny.
When the car is cold and I put the car in gear, nothing happens. Nothing
changes if I move the lever in any position. When the car has been
idling about 10 minutes after the working temperature reaches normal,
the car starts moving as normal. When the car moves again, and i press
the pedal to increase speed, it sometimes resembles the feeling like the
clutch would be slipping (on manual boxes). Could there be a somekind of
problem with the transmission oil movement. Perhaps the pump has
something wrong with it or something? And sometimes when heavily
accelerating the transmission starts slipping again. This problem is not
as mysterious as the one to follow (because It can be fixed with a trip
to transmission workshop) but I’d like to fix it myself and if anyone
could give me any suggestions I’d greatly appreciate them.

The other problem is with the cooling system. Before the vacuum
diaphragm replacement the car was constantly a bit overheated. I was
used to the problem and my driving style was adjusted according to it,
but after the change everything went to normal. The engine was nicely
cool even in heavy conditions. But approximately at the same time the
transmission problem showed up the cooling system started to act really
strangely. The car now overheats whenever It runs. The overheating shows
drastically up when idling. When the car is moving then the temperature
stays the lower the higher the speed is. As much as I have observed the
system I noticed that the electric fan isnt moving like it moved before
the system encountered problems. Now it only sometimes starts moving
when the gauge shows high temperatures. Sometimes the gauge shows 95-100
degrees C and the small fan doesnt do anything. Sometimes the temp reads
~85-89 and the fan does what it is supposed to do and the temperature
drops or stays where it is supposed to be. Before this problem appeared
the fan always worked for a while when I turned the car off, but now it
does that very rarely. Even then when the car is severely overheated. I
made a cooling fluids change a while ago (before I changed the
diaphragm) and one of my theories is that It got a bubble somewhere
where there shouldnt be one. I have vented the system from the screw on
top of the radiator and I have let air out under the cooling sensor on
the drivers side of the engine. Still the problem stays. I cant seem to
figure out any logical explanation to the problem so I’m turning to you
as the people who are somewhat more experienced in the field of jaguar
mechanics as I am. Maybe you could help me.

Thanks in advance.
Ville Lausmï¿½e===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

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Dr_Gregory_Andrachuk · March 18, 2001, 9:42pm

Ville: you have committed a cardinal sin: you have not told us anything
about the car: 6 or V12? Series and year?
Transmission: the first thing might be a complete flush and fluid
replacement. This can do wonders. If this does not help the problem then you
have mechanical item to sort out.
If the car is a V12, then raise the front of the car (chocking the rear
wheels), remove the two pressure caps on the cooling system, and squeeze the
uppper hoses a couple of times to get rid of any trapped air. Fill to the
correct level (on the cross-over pipe, not the expansion tank), and lower
the car.
Gregory----- Original Message -----
From: “Ville Lausmï¿½e” ville@wireless.ee
To: “XJ Mailing List” xj@jag-lovers.org
Sent: domingo, 18 de marzo de 2001 11:45
Subject: [xj] Problems with the transmission and cooling system.

Hi,
I was wondering if anyone here could give me some good advice on the
little “or not so little” problems with my car.
The seriousness of the problems (or the cost of repairing them) is
unknown to me because I can’t appear to find a source for the problems.

The story goes like this.
I’ve had the car for about three years. When I bought it it was
something that could be called a wreck. During these years I have spent
quite a bit of time in the garage repairing, cleaning, fixing and
generally fiddling around with the car. In the summertime (3-5 months
here) I used the car as a daily driver, during that time it never
developed any new problems. Until last autumn when I replaced the vacuum
diaphragm and got the engine nicely going. Well after changing the
vacuum diaphragm and getting the car running nicely I made quite many
speeding experiments (during one I lost my drivers license ). And
suddenly problems started to pop up. I stored the car for the winter and
decided to forget all about it for a while. But now the summer is
approaching and I’d like to fix the car to be able to use it again and
feel the enjoyment of having a Jag :).

Well one of the problems was that the transmission started acting funny.
When the car is cold and I put the car in gear, nothing happens. Nothing
changes if I move the lever in any position. When the car has been
idling about 10 minutes after the working temperature reaches normal,
the car starts moving as normal. When the car moves again, and i press
the pedal to increase speed, it sometimes resembles the feeling like the
clutch would be slipping (on manual boxes). Could there be a somekind of
problem with the transmission oil movement. Perhaps the pump has
something wrong with it or something? And sometimes when heavily
accelerating the transmission starts slipping again. This problem is not
as mysterious as the one to follow (because It can be fixed with a trip
to transmission workshop) but I’d like to fix it myself and if anyone
could give me any suggestions I’d greatly appreciate them.

The other problem is with the cooling system. Before the vacuum
diaphragm replacement the car was constantly a bit overheated. I was
used to the problem and my driving style was adjusted according to it,
but after the change everything went to normal. The engine was nicely
cool even in heavy conditions. But approximately at the same time the
transmission problem showed up the cooling system started to act really
strangely. The car now overheats whenever It runs. The overheating shows
drastically up when idling. When the car is moving then the temperature
stays the lower the higher the speed is. As much as I have observed the
system I noticed that the electric fan isnt moving like it moved before
the system encountered problems. Now it only sometimes starts moving
when the gauge shows high temperatures. Sometimes the gauge shows 95-100
degrees C and the small fan doesnt do anything. Sometimes the temp reads
~85-89 and the fan does what it is supposed to do and the temperature
drops or stays where it is supposed to be. Before this problem appeared
the fan always worked for a while when I turned the car off, but now it
does that very rarely. Even then when the car is severely overheated. I
made a cooling fluids change a while ago (before I changed the
diaphragm) and one of my theories is that It got a bubble somewhere
where there shouldnt be one. I have vented the system from the screw on
top of the radiator and I have let air out under the cooling sensor on
the drivers side of the engine. Still the problem stays. I cant seem to
figure out any logical explanation to the problem so I’m turning to you
as the people who are somewhat more experienced in the field of jaguar
mechanics as I am. Maybe you could help me.

Thanks in advance.
Ville Lausmï¿½e

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to
http://www.jag-lovers.org/cgi-bin/majordomo.

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.

Ville_Lausmae · March 18, 2001, 9:43pm

Sorry terribly, I forgot to menton what kind of car is it. The car is '88 Jaguar
XJ12 Sovereign HE.
Do you think that the cooling problem comes from air bubbles? I myself somewhat
discarded this theory becuase the car was driven perhaps about 500-1000km’s
before the problem occurred. So i thought that the car must have had enough
rattles, bumps, ups and downs for the air bubbles to come out from the system.
And the other thing that persuaded me to think like this was that at first after
the fluid replacement the car ran finely for about a month before the problems
started. But I will surely try your recommendation. But I myself have suspected
somekind of problem with the cooling sensors or water pump or something like
that. But I must admit that whatever I come up with, it all seems very
illogical.

About the transmission problem: From the archives I read something about the
pump grabbing air somewhere near the transmission oil filter. Could this be the
problem?

Kindest Regards,
Ville Lausmï¿½e

Dr Gregory Andrachuk wrote:> Ville: you have committed a cardinal sin: you have not told us anything

about the car: 6 or V12? Series and year?
Transmission: the first thing might be a complete flush and fluid
replacement. This can do wonders. If this does not help the problem then you
have mechanical item to sort out.
If the car is a V12, then raise the front of the car (chocking the rear
wheels), remove the two pressure caps on the cooling system, and squeeze the
uppper hoses a couple of times to get rid of any trapped air. Fill to the
correct level (on the cross-over pipe, not the expansion tank), and lower
the car.
Gregory
----- Original Message -----
From: “Ville Lausmï¿½e” <@Ville_Lausmae>
To: “XJ Mailing List” xj@jag-lovers.org
Sent: domingo, 18 de marzo de 2001 11:45
Subject: [xj] Problems with the transmission and cooling system.

Hi,
I was wondering if anyone here could give me some good advice on the
little “or not so little” problems with my car.
The seriousness of the problems (or the cost of repairing them) is
unknown to me because I can’t appear to find a source for the problems.

The story goes like this.
I’ve had the car for about three years. When I bought it it was
something that could be called a wreck. During these years I have spent
quite a bit of time in the garage repairing, cleaning, fixing and
generally fiddling around with the car. In the summertime (3-5 months
here) I used the car as a daily driver, during that time it never
developed any new problems. Until last autumn when I replaced the vacuum
diaphragm and got the engine nicely going. Well after changing the
vacuum diaphragm and getting the car running nicely I made quite many
speeding experiments (during one I lost my drivers license ). And
suddenly problems started to pop up. I stored the car for the winter and
decided to forget all about it for a while. But now the summer is
approaching and I’d like to fix the car to be able to use it again and
feel the enjoyment of having a Jag :).

Well one of the problems was that the transmission started acting funny.
When the car is cold and I put the car in gear, nothing happens. Nothing
changes if I move the lever in any position. When the car has been
idling about 10 minutes after the working temperature reaches normal,
the car starts moving as normal. When the car moves again, and i press
the pedal to increase speed, it sometimes resembles the feeling like the
clutch would be slipping (on manual boxes). Could there be a somekind of
problem with the transmission oil movement. Perhaps the pump has
something wrong with it or something? And sometimes when heavily
accelerating the transmission starts slipping again. This problem is not
as mysterious as the one to follow (because It can be fixed with a trip
to transmission workshop) but I’d like to fix it myself and if anyone
could give me any suggestions I’d greatly appreciate them.

The other problem is with the cooling system. Before the vacuum
diaphragm replacement the car was constantly a bit overheated. I was
used to the problem and my driving style was adjusted according to it,
but after the change everything went to normal. The engine was nicely
cool even in heavy conditions. But approximately at the same time the
transmission problem showed up the cooling system started to act really
strangely. The car now overheats whenever It runs. The overheating shows
drastically up when idling. When the car is moving then the temperature
stays the lower the higher the speed is. As much as I have observed the
system I noticed that the electric fan isnt moving like it moved before
the system encountered problems. Now it only sometimes starts moving
when the gauge shows high temperatures. Sometimes the gauge shows 95-100
degrees C and the small fan doesnt do anything. Sometimes the temp reads
~85-89 and the fan does what it is supposed to do and the temperature
drops or stays where it is supposed to be. Before this problem appeared
the fan always worked for a while when I turned the car off, but now it
does that very rarely. Even then when the car is severely overheated. I
made a cooling fluids change a while ago (before I changed the
diaphragm) and one of my theories is that It got a bubble somewhere
where there shouldnt be one. I have vented the system from the screw on
top of the radiator and I have let air out under the cooling sensor on
the drivers side of the engine. Still the problem stays. I cant seem to
figure out any logical explanation to the problem so I’m turning to you
as the people who are somewhat more experienced in the field of jaguar
mechanics as I am. Maybe you could help me.

Thanks in advance.
Ville Lausmï¿½e

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to
http://www.jag-lovers.org/cgi-bin/majordomo.

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.

Doug_Dwyer · March 18, 2001, 10:25pm

Hi,
I was wondering if anyone here could give me some good advice on the
little “or not so little” problems with my car.

Hi Ville. Next time include some details about your Jag such as year,
engine, and mileage. All the details help ! Now, back to business.

I stored the car for the winter and
decided to forget all about it for a while. But now the summer is
approaching and I’d like to fix the car to be able to use it again and
feel the enjoyment of having a Jag :).

Proof that Jaguars are like racehorses…they need plenty of exercise !

Well one of the problems was that the transmission started acting funny.
When the car is cold and I put the car in gear, nothing happens. Nothing
changes if I move the lever in any position. When the car has been
idling about 10 minutes after the working temperature reaches normal,
the car starts moving as normal.

Assuming you checked the fluid level and it is OK the most likely cause of
this problem is the internal transmission seals. With age and mileage the
seals tend to become hardened, especially when cold. A hardened seal does
not do it’s job very well and will allow fluid pressures to drop. After
running for a few minutes the warmth softens the seals and allows them to do
their job. Internal transmission pressures then increase and the various
hydraulically controlled servos and pistons will now operate as designed.

When the car moves again, and i press
the pedal to increase speed, it sometimes resembles the feeling like the
clutch would be slipping (on manual boxes). Could there be a somekind of
problem with the transmission oil movement. Perhaps the pump has
something wrong with it or something? And sometimes when heavily
accelerating the transmission starts slipping again.

Could be that the seals are worn beyond redemption and/or the clutch plates
are so badly worn that they no longer grip. On the bright side the problem
may be as simple as out-of-adjustment bands. If you have a 6 cylinder Jag or
an older 12 cylinder model then you’ll have a Borg-Warner transmission with
externally adjustable bands. A trans repair shop can put things right for
you or, with the help of a workshop manual, you can try the adjustment
procedure yourself.

Another possibility is that your storage period allowed some of the shuttle
valves in the valve body to stick. This would prevent proper application of
hydraulic pressure within the transmission. In some cases a transmission
fluid flush will solve this problem. Removing the valves themselves for
cleaning is an alternative but probably not a good idea for a novice.

Lastly, and regrettably, your transmission may just be worn out and due for
a routine overhaul with new seals, clutches, bands, etc. Tending to this
promptly may prevent a routine overhaul from turning into a major overhaul
where major components (“hard parts”) will require replacement.

The other problem is with the cooling system.

But approximately at the same time the
transmission problem showed up the cooling system started to act really
strangely. The car now overheats whenever It runs. The overheating shows
drastically up when idling.

A slipping transmission creates extra work for the engine due to increased
RPM. Additionally, when the transmission is slipping the fluid becomes very
hot. As this hot fluid passes through the transmission cooler this heat is
absorbed into the engine coolant due to the thermal exchange within the
cooler itself. If your cooling system was marginal to begin with the extra
heat imposed by the slipping trans may just be too much.

However, i suspect a problem within your cooling system itself. The common
culprits would be a clogged radiator, sticking thermostat, or inoperative
fan clutch (if your Jag is equipped with a thermal type clutch). Considering
that your car was stored for some time I would be suspicious of a sticking
thermostat…as a first guess.

Any sign of coolant leaks ? White smoke from the exhaust ?

As much as I have observed the
system I noticed that the electric fan isnt moving like it moved before
the system encountered problems. Now it only sometimes starts moving
when the gauge shows high temperatures. Sometimes the gauge shows 95-100
degrees C and the small fan doesnt do anything.

“Assuming” you have a Series III Xj6 the auxilary fan should seldom be
needed as these cars run fairly cool. If the coolong system is in good
order the motor would normally run at about 88C-90C degrees in all but very
extreme condtions, when 95C-100C might be seen. (What are the ambient
conditions in your area, by the way ?) The fan should come on at 95C.
Erratic operation of the aux fan may be an electrical problem and not
specifically related to the cooling system. No matter. Unless you’re in the
Kalahari you can get by without it.

I cant seem to
figure out any logical explanation to the problem so I’m turning to you
as the people who are somewhat more experienced in the field of jaguar
mechanics as I am. Maybe you could help me.

Please post back with some more details about your car and we’ll press
onwards.

Cheers,
Doug Dwyer----- Original Message -----
From: “Ville Lausmï¿½e” ville@wireless.ee

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.

Doug_Dwyer · March 18, 2001, 10:34pm

Sorry terribly, I forgot to menton what kind of car is it. The car is '88
Jaguar
XJ12 Sovereign HE.

Twelve cylinder HE? Ok, Ville. NOW we know why you found it so easy to
run afoul of the gendarmes !

Doug Dwyer----- Original Message -----
From: “Ville Lausmï¿½e” ville@wireless.ee

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.

Ville_Lausmae · March 18, 2001, 11:46pm

Ok, I will check that there isnt any debris in front of the radiator, but isnt
it logical to think that there isnt any debris there because the car mostly
overheats when not moving. And that the problem occurred suddenly, by the day,
not over some time progressively worsening the cooling capability. But I will
check it out.
So will I try to check that there arent any air bubbles in the system.

Since I live in Estonia, where 10 years ago we hadnt seen any cars exept
russian, there isnt much history in knowledge of advanced mechanics maintenance,
as jaguar v12 definently is. I must ask what exactly do you mean by servicing
the distributor. I Changed the vacuum diaphragm myself… that means, I
disconnected the old one, and mounted the new one. Do you mean that I should
open it up again to check if it is properly attached to the distributor. But I
personally dont think that the problem is in the vacuum membrane because the car
overheats more than it overheated before the diaphragm replacement. (After
changing it, the cooling was normal for a while)
There is only one workshop in my country that deals with jaguars, and their
pricing on the parts is quite high (+400%). The hour of work costs about 1/5th
of an average persons monthly payroll. So I have to do most of the work myself,
and there isnt many people to ask for advice exept you people on the list.

And I am most embarrassed to ask this, but how exactly goes the procedure of
checking the oil levels on the transmission :)? Does the car have to be running?
And If it is running, should there be a reading on the rod(on the hot side)
between min/max? Or should I check it when the engine isnt running and the
engine is warm? Or when the engine is cold and then read from the cold side? How
does the procedure actually go. And for checking purposes, If I find that the
fluid level is low, can I pour transmission oil into the trasmission from the
pipe where the rod with level readings is placed in?

BTW What does chocking the rear wheels mean? Sorry to ask this but doesnt seem
to make sense to me, maybe the reason is my poor english, sorry

And thanks to Jagspares for the advice on checking the fan clutch. I will check
it too. But shouldnt the small fan (electric) try to compensate by starting to
work? What are the basis the small fan works? Under what conditions does it
start? And when :)? Mine works quite randomly, not according the temperature.
I just received the mail about refilling the system with the heater on. Should I
refill the system? That means, acquire new cooling fluid and refill the engine
on a slope with nose up. Should the procedure go something like this:

I empty the system
I get the car nose up
I turn on the heater (not the engine :))
I fill the system
Still on a slope, I turn on the engine, let it run until normal temperature
is reached (that is about 80+C, still under the “green” line)
While it is running, I top the system.
Then I check that it is filled
I take the car down from the slope, and check that the system is topped and
vent the system from the top of the radiator.

And by the way, what is the exact correct coolant temperature raeding. I assume
that the “green” area on the gauge, starting from about 89C is actually the
“red” area.

Kindest Regards,
Ville Lausmï¿½e

Dr Gregory Andrachuk wrote:> OK: now we are in business: a V12 with the GM TH400 transmission.

Yes, raising the front end will help ensure that any air trapped in the
system escapes. On this car, leaves and other debris can be trapped between
the condenser and the radiator, effectively blocking the air flow to almost
one third of the radiator. Having this cleaned out may go a long way to
solving the problem. You should also make sure that the distributor has been
serviced, especially ensuring that the vacuum advance is working properly
(but I think you said this was recently done).
Transmission: the first thing to do is to ensure that the
fluid level is correct. If that is not the problem, then next a complete
flush and refill is in order.
Gregory
----- Original Message -----
From: “Ville Lausmï¿½e” <@Ville_Lausmae>
To: “Dr Gregory Andrachuk” mgb@uvvm.uvic.ca; xj@jag-lovers.org
Sent: domingo, 18 de marzo de 2001 13:43
Subject: Re: [xj] Problems with the transmission and cooling system.

Sorry terribly, I forgot to menton what kind of car is it. The car is '88
Jaguar
XJ12 Sovereign HE.
Do you think that the cooling problem comes from air bubbles? I myself
somewhat
discarded this theory becuase the car was driven perhaps about 500-1000km’s
before the problem occurred. So i thought that the car must have had enough
rattles, bumps, ups and downs for the air bubbles to come out from the
system.
And the other thing that persuaded me to think like this was that at first
after
the fluid replacement the car ran finely for about a month before the
problems
started. But I will surely try your recommendation. But I myself have
suspected
somekind of problem with the cooling sensors or water pump or something like
that. But I must admit that whatever I come up with, it all seems very
illogical.

About the transmission problem: From the archives I read something about the
pump grabbing air somewhere near the transmission oil filter. Could this be
the
problem?

Kindest Regards,
Ville Lausmï¿½e

Dr Gregory Andrachuk wrote:

Ville: you have committed a cardinal sin: you have not told us anything
about the car: 6 or V12? Series and year?
Transmission: the first thing might be a complete flush and fluid
replacement. This can do wonders. If this does not help the problem then
you
have mechanical item to sort out.
If the car is a V12, then raise the front of the car (chocking the
rear
wheels), remove the two pressure caps on the cooling system, and squeeze
the
uppper hoses a couple of times to get rid of any trapped air. Fill to the
correct level (on the cross-over pipe, not the expansion tank), and lower
the car.
Gregory
----- Original Message -----
From: “Ville Lausmï¿½e” <@Ville_Lausmae>
To: “XJ Mailing List” xj@jag-lovers.org
Sent: domingo, 18 de marzo de 2001 11:45
Subject: [xj] Problems with the transmission and cooling system.

Hi,
I was wondering if anyone here could give me some good advice on the
little “or not so little” problems with my car.
The seriousness of the problems (or the cost of repairing them) is
unknown to me because I can’t appear to find a source for the problems.

The story goes like this.
I’ve had the car for about three years. When I bought it it was
something that could be called a wreck. During these years I have spent
quite a bit of time in the garage repairing, cleaning, fixing and
generally fiddling around with the car. In the summertime (3-5 months
here) I used the car as a daily driver, during that time it never
developed any new problems. Until last autumn when I replaced the vacuum
diaphragm and got the engine nicely going. Well after changing the
vacuum diaphragm and getting the car running nicely I made quite many
speeding experiments (during one I lost my drivers license ). And
suddenly problems started to pop up. I stored the car for the winter and
decided to forget all about it for a while. But now the summer is
approaching and I’d like to fix the car to be able to use it again and
feel the enjoyment of having a Jag :).

Well one of the problems was that the transmission started acting funny.
When the car is cold and I put the car in gear, nothing happens. Nothing
changes if I move the lever in any position. When the car has been
idling about 10 minutes after the working temperature reaches normal,
the car starts moving as normal. When the car moves again, and i press
the pedal to increase speed, it sometimes resembles the feeling like the
clutch would be slipping (on manual boxes). Could there be a somekind of
problem with the transmission oil movement. Perhaps the pump has
something wrong with it or something? And sometimes when heavily
accelerating the transmission starts slipping again. This problem is not
as mysterious as the one to follow (because It can be fixed with a trip
to transmission workshop) but I’d like to fix it myself and if anyone
could give me any suggestions I’d greatly appreciate them.

The other problem is with the cooling system. Before the vacuum
diaphragm replacement the car was constantly a bit overheated. I was
used to the problem and my driving style was adjusted according to it,
but after the change everything went to normal. The engine was nicely
cool even in heavy conditions. But approximately at the same time the
transmission problem showed up the cooling system started to act really
strangely. The car now overheats whenever It runs. The overheating shows
drastically up when idling. When the car is moving then the temperature
stays the lower the higher the speed is. As much as I have observed the
system I noticed that the electric fan isnt moving like it moved before
the system encountered problems. Now it only sometimes starts moving
when the gauge shows high temperatures. Sometimes the gauge shows 95-100
degrees C and the small fan doesnt do anything. Sometimes the temp reads
~85-89 and the fan does what it is supposed to do and the temperature
drops or stays where it is supposed to be. Before this problem appeared
the fan always worked for a while when I turned the car off, but now it
does that very rarely. Even then when the car is severely overheated. I
made a cooling fluids change a while ago (before I changed the
diaphragm) and one of my theories is that It got a bubble somewhere
where there shouldnt be one. I have vented the system from the screw on
top of the radiator and I have let air out under the cooling sensor on
the drivers side of the engine. Still the problem stays. I cant seem to
figure out any logical explanation to the problem so I’m turning to you
as the people who are somewhat more experienced in the field of jaguar
mechanics as I am. Maybe you could help me.

Thanks in advance.
Ville Lausmï¿½e

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to
http://www.jag-lovers.org/cgi-bin/majordomo.

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to
http://www.jag-lovers.org/cgi-bin/majordomo.

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

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Dr_Gregory_Andrachuk · March 18, 2001, 11:22pm

OK: now we are in business: a V12 with the GM TH400 transmission.
Yes, raising the front end will help ensure that any air trapped in the
system escapes. On this car, leaves and other debris can be trapped between
the condenser and the radiator, effectively blocking the air flow to almost
one third of the radiator. Having this cleaned out may go a long way to
solving the problem. You should also make sure that the distributor has been
serviced, especially ensuring that the vacuum advance is working properly
(but I think you said this was recently done).
Transmission: the first thing to do is to ensure that the
fluid level is correct. If that is not the problem, then next a complete
flush and refill is in order.
Gregory----- Original Message -----
From: “Ville Lausmï¿½e” ville@wireless.ee
To: “Dr Gregory Andrachuk” <@Gregory_Andrachuk>; xj@jag-lovers.org
Sent: domingo, 18 de marzo de 2001 13:43
Subject: Re: [xj] Problems with the transmission and cooling system.

Sorry terribly, I forgot to menton what kind of car is it. The car is '88
Jaguar
XJ12 Sovereign HE.
Do you think that the cooling problem comes from air bubbles? I myself
somewhat
discarded this theory becuase the car was driven perhaps about 500-1000km’s
before the problem occurred. So i thought that the car must have had enough
rattles, bumps, ups and downs for the air bubbles to come out from the
system.
And the other thing that persuaded me to think like this was that at first
after
the fluid replacement the car ran finely for about a month before the
problems
started. But I will surely try your recommendation. But I myself have
suspected
somekind of problem with the cooling sensors or water pump or something like
that. But I must admit that whatever I come up with, it all seems very
illogical.

About the transmission problem: From the archives I read something about the
pump grabbing air somewhere near the transmission oil filter. Could this be
the
problem?

Kindest Regards,
Ville Lausmï¿½e

Dr Gregory Andrachuk wrote:

Ville: you have committed a cardinal sin: you have not told us anything
about the car: 6 or V12? Series and year?
Transmission: the first thing might be a complete flush and fluid
replacement. This can do wonders. If this does not help the problem then
you
have mechanical item to sort out.
If the car is a V12, then raise the front of the car (chocking the
rear
wheels), remove the two pressure caps on the cooling system, and squeeze
the
uppper hoses a couple of times to get rid of any trapped air. Fill to the
correct level (on the cross-over pipe, not the expansion tank), and lower
the car.
Gregory
----- Original Message -----
From: “Ville Lausmï¿½e” ville@wireless.ee
To: “XJ Mailing List” xj@jag-lovers.org
Sent: domingo, 18 de marzo de 2001 11:45
Subject: [xj] Problems with the transmission and cooling system.

Hi,
I was wondering if anyone here could give me some good advice on the
little “or not so little” problems with my car.
The seriousness of the problems (or the cost of repairing them) is
unknown to me because I can’t appear to find a source for the problems.

The story goes like this.
I’ve had the car for about three years. When I bought it it was
something that could be called a wreck. During these years I have spent
quite a bit of time in the garage repairing, cleaning, fixing and
generally fiddling around with the car. In the summertime (3-5 months
here) I used the car as a daily driver, during that time it never
developed any new problems. Until last autumn when I replaced the vacuum
diaphragm and got the engine nicely going. Well after changing the
vacuum diaphragm and getting the car running nicely I made quite many
speeding experiments (during one I lost my drivers license ). And
suddenly problems started to pop up. I stored the car for the winter and
decided to forget all about it for a while. But now the summer is
approaching and I’d like to fix the car to be able to use it again and
feel the enjoyment of having a Jag :).

Well one of the problems was that the transmission started acting funny.
When the car is cold and I put the car in gear, nothing happens. Nothing
changes if I move the lever in any position. When the car has been
idling about 10 minutes after the working temperature reaches normal,
the car starts moving as normal. When the car moves again, and i press
the pedal to increase speed, it sometimes resembles the feeling like the
clutch would be slipping (on manual boxes). Could there be a somekind of
problem with the transmission oil movement. Perhaps the pump has
something wrong with it or something? And sometimes when heavily
accelerating the transmission starts slipping again. This problem is not
as mysterious as the one to follow (because It can be fixed with a trip
to transmission workshop) but I’d like to fix it myself and if anyone
could give me any suggestions I’d greatly appreciate them.

The other problem is with the cooling system. Before the vacuum
diaphragm replacement the car was constantly a bit overheated. I was
used to the problem and my driving style was adjusted according to it,
but after the change everything went to normal. The engine was nicely
cool even in heavy conditions. But approximately at the same time the
transmission problem showed up the cooling system started to act really
strangely. The car now overheats whenever It runs. The overheating shows
drastically up when idling. When the car is moving then the temperature
stays the lower the higher the speed is. As much as I have observed the
system I noticed that the electric fan isnt moving like it moved before
the system encountered problems. Now it only sometimes starts moving
when the gauge shows high temperatures. Sometimes the gauge shows 95-100
degrees C and the small fan doesnt do anything. Sometimes the temp reads
~85-89 and the fan does what it is supposed to do and the temperature
drops or stays where it is supposed to be. Before this problem appeared
the fan always worked for a while when I turned the car off, but now it
does that very rarely. Even then when the car is severely overheated. I
made a cooling fluids change a while ago (before I changed the
diaphragm) and one of my theories is that It got a bubble somewhere
where there shouldnt be one. I have vented the system from the screw on
top of the radiator and I have let air out under the cooling sensor on
the drivers side of the engine. Still the problem stays. I cant seem to
figure out any logical explanation to the problem so I’m turning to you
as the people who are somewhat more experienced in the field of jaguar
mechanics as I am. Maybe you could help me.

Thanks in advance.
Ville Lausmï¿½e

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to
http://www.jag-lovers.org/cgi-bin/majordomo.

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to
http://www.jag-lovers.org/cgi-bin/majordomo.

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.

Doug_Dwyer · March 19, 2001, 12:45am

And I am most embarrassed to ask this, but how exactly goes the procedure
of
checking the oil levels on the transmission :)? Does the car have to be
running?

Yes, the engine must be running and the transmission fluid must be hot so
check the level after driving for 15 minutes or so.

And If it is running, should there be a reading on the rod(on the hot
side)
between min/max?

Exactly. The correct level is between “min/max”.

How does the procedure actually go.

With engine running and selector lever in “P”, withdraw the dipstick (“rod”,
in your parlance !). Wipe it off, reinsert it, then pull it out and
immediately observe the fluid level reading.

And for checking purposes, If I find that the
fluid level is low, can I pour transmission oil into the trasmission from
the
pipe where the rod with level readings is placed in?

That is exactly correct. Use “Dexron” type transmission fluid. Add about a
half liter at a time …then recheck the level…to avoid over-filling.

BTW What does chocking the rear wheels mean? Sorry to ask this but doesnt
seem
to make sense to me, maybe the reason is my poor english, sorry

No apology needed. “Chocking the wheels” means blocking them so the car
won’t roll.

Doug Dwyer----- Original Message -----
From: “Ville Lausmï¿½e” ville@wireless.ee

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.

Dr_Gregory_Andrachuk · March 19, 2001, 1:09am

Ville: you are a brave man, running a V12 Jaguar where there is no or little
service support. You deserve some sort of award from Jag-lovers.
You do not need to empty the cooling system. Turn the climate control to
DEFROST. Remove the filler caps. Fill the system from the crossover pipe
filler until the coolant level is about 2 inches below the filler neck. Put
blocks behind the rear wheels (these are called “chocks”). Replace the caps;
run the engine until the temperature is at 90 (this is the normal running
temperature of the engine. The upper part of the green band is equivalent to
an orange/red area; this is a Jaguar idiosyncracy). When the engine has
cooled, remove the caps, and fill again until the level is correct (as
above).
If the car overheats while stationary, that can indeed mean that the rad
is blocked either by debris, or internally.
The electric fan on the 88 V12 runs 1) when the climate control is ON
or 2) when the
coolant temperature reaches a predetermined level (I think it is 95 degrees
C).

Transmission: the level is checked while the car is on level ground; the
dipstick has a cold and a hot reading. The hot is used ONLY when the car has
travelled more than 25 or 30 kilometers. To check, move the transmission
lever from P through ALL the gear positions, slowly, allowing time for the
fluid to circulate. Then place the lever back in P and withdraw the
dipstick. Read the level, and if necessary add DEXRON III (no other)
transmission fluid through the filler pipe (yes, the pipe for the dipstick).
Do NOT overfill the transmission.
I hope this helps.
Gregory---- Original Message -----
From: “Ville Lausmï¿½e” ville@wireless.ee
To: “Dr Gregory Andrachuk” <@Gregory_Andrachuk>; xj@jag-lovers.org;
sales@jagspares.com.au
Sent: domingo, 18 de marzo de 2001 15:46
Subject: Re: [xj] Problems with the transmission and cooling system.

Ok, I will check that there isnt any debris in front of the radiator, but
isnt
it logical to think that there isnt any debris there because the car
mostly
overheats when not moving. And that the problem occurred suddenly, by the
day,
not over some time progressively worsening the cooling capability. But I
will
check it out.
So will I try to check that there arent any air bubbles in the system.

Since I live in Estonia, where 10 years ago we hadnt seen any cars exept
russian, there isnt much history in knowledge of advanced mechanics
maintenance,
as jaguar v12 definently is. I must ask what exactly do you mean by
servicing
the distributor. I Changed the vacuum diaphragm myself… that means, I
disconnected the old one, and mounted the new one. Do you mean that I
should
open it up again to check if it is properly attached to the distributor.
But I
personally dont think that the problem is in the vacuum membrane because
the car
overheats more than it overheated before the diaphragm replacement. (After
changing it, the cooling was normal for a while)
There is only one workshop in my country that deals with jaguars, and
their
pricing on the parts is quite high (+400%). The hour of work costs about
1/5th
of an average persons monthly payroll. So I have to do most of the work
myself,
and there isnt many people to ask for advice exept you people on the list.

And I am most embarrassed to ask this, but how exactly goes the procedure
of
checking the oil levels on the transmission :)? Does the car have to be
running?
And If it is running, should there be a reading on the rod(on the hot
side)
between min/max? Or should I check it when the engine isnt running and the
engine is warm? Or when the engine is cold and then read from the cold
side? How
does the procedure actually go. And for checking purposes, If I find that
the
fluid level is low, can I pour transmission oil into the trasmission from
the
pipe where the rod with level readings is placed in?

BTW What does chocking the rear wheels mean? Sorry to ask this but doesnt
seem
to make sense to me, maybe the reason is my poor english, sorry

And thanks to Jagspares for the advice on checking the fan clutch. I will
check
it too. But shouldnt the small fan (electric) try to compensate by
starting to
work? What are the basis the small fan works? Under what conditions does
it
start? And when :)? Mine works quite randomly, not according the
temperature.
I just received the mail about refilling the system with the heater on.
Should I
refill the system? That means, acquire new cooling fluid and refill the
engine
on a slope with nose up. Should the procedure go something like this:

I empty the system

I get the car nose up

I turn on the heater (not the engine :))

I fill the system

Still on a slope, I turn on the engine, let it run until normal
temperature
is reached (that is about 80+C, still under the “green” line)

While it is running, I top the system.

Then I check that it is filled

I take the car down from the slope, and check that the system is topped
and
vent the system from the top of the radiator.

And by the way, what is the exact correct coolant temperature raeding. I
assume
that the “green” area on the gauge, starting from about 89C is actually
the
“red” area.

Kindest Regards,
Ville Lausmde

Dr Gregory Andrachuk wrote:

OK: now we are in business: a V12 with the GM TH400 transmission.
Yes, raising the front end will help ensure that any air trapped in the
system escapes. On this car, leaves and other debris can be trapped
between

the condenser and the radiator, effectively blocking the air flow to
almost

one third of the radiator. Having this cleaned out may go a long way to
solving the problem. You should also make sure that the distributor has
been

serviced, especially ensuring that the vacuum advance is working
properly

(but I think you said this was recently done).
Transmission: the first thing to do is to ensure that
the

fluid level is correct. If that is not the problem, then next a complete
flush and refill is in order.
Gregory
----- Original Message -----
From: “Ville Lausmde” ville@wireless.ee
To: “Dr Gregory Andrachuk” <@Gregory_Andrachuk>; xj@jag-lovers.org
Sent: domingo, 18 de marzo de 2001 13:43
Subject: Re: [xj] Problems with the transmission and cooling system.

Sorry terribly, I forgot to menton what kind of car is it. The car is
'88

Jaguar
XJ12 Sovereign HE.
Do you think that the cooling problem comes from air bubbles? I myself
somewhat
discarded this theory becuase the car was driven perhaps about
500-1000km’s

before the problem occurred. So i thought that the car must have had
enough

rattles, bumps, ups and downs for the air bubbles to come out from the
system.
And the other thing that persuaded me to think like this was that at
first

after
the fluid replacement the car ran finely for about a month before the
problems
started. But I will surely try your recommendation. But I myself have
suspected
somekind of problem with the cooling sensors or water pump or something
like

that. But I must admit that whatever I come up with, it all seems very
illogical.

About the transmission problem: From the archives I read something about
the

pump grabbing air somewhere near the transmission oil filter. Could this
be

the
problem?

Kindest Regards,
Ville Lausmde

Dr Gregory Andrachuk wrote:

Ville: you have committed a cardinal sin: you have not told us
anything

about the car: 6 or V12? Series and year?
Transmission: the first thing might be a complete flush and fluid
replacement. This can do wonders. If this does not help the problem
then

you

have mechanical item to sort out.
If the car is a V12, then raise the front of the car (chocking the
rear
wheels), remove the two pressure caps on the cooling system, and
squeeze

the

uppper hoses a couple of times to get rid of any trapped air. Fill to
the

correct level (on the cross-over pipe, not the expansion tank), and
lower

the car.
Gregory
----- Original Message -----
From: “Ville Lausmde” ville@wireless.ee
To: “XJ Mailing List” xj@jag-lovers.org
Sent: domingo, 18 de marzo de 2001 11:45
Subject: [xj] Problems with the transmission and cooling system.

Hi,
I was wondering if anyone here could give me some good advice on the
little “or not so little” problems with my car.
The seriousness of the problems (or the cost of repairing them) is
unknown to me because I can’t appear to find a source for the
problems.

The story goes like this.
I’ve had the car for about three years. When I bought it it was
something that could be called a wreck. During these years I have
spent

quite a bit of time in the garage repairing, cleaning, fixing and
generally fiddling around with the car. In the summertime (3-5 months
here) I used the car as a daily driver, during that time it never
developed any new problems. Until last autumn when I replaced the
vacuum

diaphragm and got the engine nicely going. Well after changing the
vacuum diaphragm and getting the car running nicely I made quite many
speeding experiments (during one I lost my drivers license ). And
suddenly problems started to pop up. I stored the car for the winter
and

decided to forget all about it for a while. But now the summer is
approaching and I’d like to fix the car to be able to use it again and
feel the enjoyment of having a Jag :).

Well one of the problems was that the transmission started acting
funny.

When the car is cold and I put the car in gear, nothing happens.
Nothing

changes if I move the lever in any position. When the car has been
idling about 10 minutes after the working temperature reaches normal,
the car starts moving as normal. When the car moves again, and i press
the pedal to increase speed, it sometimes resembles the feeling like
the

clutch would be slipping (on manual boxes). Could there be a somekind
of

problem with the transmission oil movement. Perhaps the pump has
something wrong with it or something? And sometimes when heavily
accelerating the transmission starts slipping again. This problem is
not

as mysterious as the one to follow (because It can be fixed with a
trip

to transmission workshop) but I’d like to fix it myself and if anyone
could give me any suggestions I’d greatly appreciate them.

The other problem is with the cooling system. Before the vacuum
diaphragm replacement the car was constantly a bit overheated. I was
used to the problem and my driving style was adjusted according to it,
but after the change everything went to normal. The engine was nicely
cool even in heavy conditions. But approximately at the same time the
transmission problem showed up the cooling system started to act
really

strangely. The car now overheats whenever It runs. The overheating
shows

drastically up when idling. When the car is moving then the
temperature

stays the lower the higher the speed is. As much as I have observed
the

system I noticed that the electric fan isnt moving like it moved
before

the system encountered problems. Now it only sometimes starts moving
when the gauge shows high temperatures. Sometimes the gauge shows
95-100

degrees C and the small fan doesnt do anything. Sometimes the temp
reads

~85-89 and the fan does what it is supposed to do and the temperature
drops or stays where it is supposed to be. Before this problem
appeared

the fan always worked for a while when I turned the car off, but now
it

does that very rarely. Even then when the car is severely overheated.
I

made a cooling fluids change a while ago (before I changed the
diaphragm) and one of my theories is that It got a bubble somewhere
where there shouldnt be one. I have vented the system from the screw
on

top of the radiator and I have let air out under the cooling sensor on
the drivers side of the engine. Still the problem stays. I cant seem
to

figure out any logical explanation to the problem so I’m turning to
you

as the people who are somewhat more experienced in the field of jaguar
mechanics as I am. Maybe you could help me.

Thanks in advance.
Ville Lausmde

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to
http://www.jag-lovers.org/cgi-bin/majordomo.

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to
http://www.jag-lovers.org/cgi-bin/majordomo.

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.