Larry, what I’m about to suggest is a real stretch, but, what the hell.
I believe you mentioned that the water rail was replaced. Any possibility
that it is partially restricted?
Also, have you checked the accuracy of your gauge? (This has been going on
so long I can’t remember)
Doug Dwyer
Longview, Washington USA
Unfortunately on the 40 mile return trip, same as the 40 mile
trek out there, the highway tems are now 96C, and the residential
traffic temps are around 98C. Not good at all.
// list policy dictates that messages be trimmedFrom: “Larry Karpman” lkarpman@attbi.com
In a message dated 6/9/02 5:43:00 PM Pacific Daylight Time, lkarpman@attbi.com writes:
<< We had our Dallas area XJ ‘‘wrench turning’’ session today. Henry
Fok checked my timing, and it is set at 6 degrees BTDC not 4 as
it should. Don’t know how dramatically that effects the temp. He
also found my PS belt way too loose. >>
Larry. Your timing should be set to 14 BTDC not 4. Jaguar issued a directive
in one of their training manuals that I had the opportunity to read, that
stated, because of the many complaints that Jaguar received over a lumpy idle
on these cars. They advise the mechanics to set the car to 14 degree’s BTDC
and work down to 10 degree’s. Then settle on whatever allows the smoothest
idle. Final adjustment could then be conducted using the idle mixture
adjuster screw. My cars are all set to 12 degree’s BFTD as that seems to be
their optimum performance point, plus they all pass the emissions test at
that setting.
In reply to a message from Doug Dwyer sent Mon 10 Jun 2002:
Yes Doug, it HAS been going on too long, and no one more than me
would like to end it.
The gauge has not been checked, but it is one of the last things
I suspect. When I first got the car back to Texas, the fan
activation switch is OEM for 100 degrees. The one time in Texas,
eraly on before any work was done, that it hit 100C on the gauge
the fans kicked on. Now I know these are not that accurate, but I
changed to a 95C sitch when I had the rad done, and now they will
kick on when the gauge says 95C.
As for the water rail, it’s possible, but the one I put on was a
NOS OEM that had never been on a car before. Stranger things have
happened.
Cheers–
The original message included these comments:
I believe you mentioned that the water rail was replaced. Any possibility
that it is partially restricted?
Also, have you checked the accuracy of your gauge? (This has been going on
so long I can’t remember)
Doug Dwyer
–
Larry Karpman '87 SIII VDP (US), '79 SIII XJ6 (US)
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
I don’t doubt what you read, but wouldn’t that be quite a stretch
from 4 degrees? I could see retarding from 17 degrees to 14
without too much trouble, but advancing from a spec (for the '79)
from 4 all the way to 17 seem rather dramatic.
Of course, I have no idea of the differences in the '79 engine
and setup vs, lets say, and '85.
Cheers–
The original message included these comments:
Larry. Your timing should be set to 14 BTDC not 4. Jaguar issued a directive
in one of their training manuals that I had the opportunity to read, that
stated, because of the many complaints that Jaguar received over a lumpy idle
on these cars. They advise the mechanics to set the car to 14 degree’s BTDC
and work down to 10 degree’s. Then settle on whatever allows the smoothest
idle. Final adjustment could then be conducted using the idle mixture
–
Larry Karpman '87 SIII VDP (US), '79 SIII XJ6 (US)
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Larry, if you’re really at 98C when driving around, your aux fan should be
on. Can you hear it? Stop when you see 98 and see if it’s on. If not, but
if you know it does come on once in a while, then I’d agree with Doug that
your gauge or sender (the one with the single green wire) could be trouble.–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.
Larry Karpman wrote:
In reply to a message from Arnoud sent Sun 9 Jun 2002:
Arnoud:
Nice input. Good, I’m glad a clutch that acts like mine can do
the job!
We had our Dallas area XJ ‘‘wrench turning’’ session today. Henry
Fok checked my timing, and it is set at 6 degrees BTDC not 4 as
it should. Don’t know how dramatically that effects the temp. He
also found my PS belt way too loose.
Unfortunately on the 40 mile return trip, same as the 40 mile
trek out there, the highway tems are now 96C, and the residential
traffic temps are around 98C. Not good at all.
Soooooo, even after I put in the tested 88C Waxstat, put in a
third OEM fan clutch, and have a freshly rodded radiator, I’m
here
I’m haunted by the 2 weeks it all ran great, until ‘‘something’’
decided to fail. I have replaced the clutch put in by the shop,
repalced the thermo put in by them.
I’m going to get a pressure tester and check to see if the
cooling system is holding pressure.
I’d certainly not advise removal of the aux fans. If the standard setup can’t
cool the engine, something’s wrong. Our SII has 2 aux fans and when our main
fan froze up on the way to a smog test a few years ago, I just removed it.
The engine ran fine with just the aux fans, even when it was idling at the
smog test. The higher temp likely helped it pass. :]
In fact, I was so impressed with normal driving airflow cooling the engine,
with no fan or shroud (aux fans off), that I knew it would be a cinch to go
all electric. Never regretted that, and the e-fan for the SIII is just now
waiting installation. With the OE fan & shroud removed, the car should cool
itself at 30 mph or higher, with aux fans only coming on when idling at a
light.–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.
Frank Andersen wrote:
Larry Karpman wrote:
[clip]
I’m hesitant to drive any greater distance, so my question now is
this. I know the kitty isn’t performing to standard, but how bad
off is she? (please don’t say 4 degrees off
Get rid of those auxilliary fans, Larry! They are clearly impeding an
already precarious airflow through the radiator, which is the basic
problem.
As an alternative, or to demonstrate the point, set them to run
continuously for a spin. And if you insist on keeping them, at least
ensure that they come on at, say, 5C below thermostat temperature.
In reply to a message from Cannara sent Mon 10 Jun 2002:
Alex:
It comes on exactly when the gauge says 95C 100% of the time. So,
although we know they’re are not always that accurate, the gauge
and sensor seem to agree at the 95C mark.
Cheers–
The original message included these comments:
Larry, if you’re really at 98C when driving around, your aux fan should be
on. Can you hear it? Stop when you see 98 and see if it’s on. If not, but
if you know it does come on once in a while, then I’d agree with Doug that
your gauge or sender (the one with the single green wire) could be trouble.
Alex
–
Larry Karpman '87 SIII VDP (US), '79 SIII XJ6 (US)
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Ok, good. Now what happens when you do a stress test – drive up a long hill
as fast as you can in 3rd? Does she shoot much higher than when just idling?
I forget what your compression readings were when warm also.–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.
Larry Karpman wrote:
In reply to a message from Cannara sent Mon 10 Jun 2002:
Alex:
It comes on exactly when the gauge says 95C 100% of the time. So,
although we know they’re are not always that accurate, the gauge
and sensor seem to agree at the 95C mark.
In reply to a message from Cannara sent Mon 10 Jun 2002:
OK Alex, pack up one of those Northern California hills and send
here to the flatlands of Texas and I’ll try it
One thing I did note on the 80 mile trek today was that the temps
made no difference with a/c on or off. In fact, I’m convinced it
ran a degree or so cooler with the a/c on. Probably just a mirage
from staring at the gauge for 80 miles.
Cheers–
The original message included these comments:
Ok, good. Now what happens when you do a stress test – drive up a long hill
as fast as you can in 3rd? Does she shoot much higher than when just idling?
I forget what your compression readings were when warm also.
Alex
–
Larry Karpman '87 SIII VDP (US), '79 SIII XJ6 (US)
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Cannara sent Mon 10 Jun 2002:
OK Alex, pack up one of those Northern California hills and send
here to the flatlands of Texas and I’ll try it
One thing I did note on the 80 mile trek today was that the temps
made no difference with a/c on or off. In fact, I’m convinced it
ran a degree or so cooler with the a/c on. Probably just a mirage
from staring at the gauge for 80 miles.
There is no reason why a properly working cooling system should run
hotter just because A/C is on?
There is no reason why a properly working cooling system should run
hotter just because A/C is on?
Frank
actually there is, since the A/C rad sits in front of the coolant
rad. With A/C on the heated air generated by the A/C rad will flow
through the coolant rad. This should only make a marginal difference
tho.–
Arnoud
iMac, therefore I am
1973 Daimler Double-Six SWB
1989 Jaguar Sovereign HE
With the OE fan & shroud removed, the car should cool
itself at 30 mph or higher, with aux fans only coming on when idling at a
light.
Alex, or any other SII owner-
When this happens, what does the temp gauge show? All the posts have used
numerical values, but as you know, the SII has a gauge that only indicates
a “Normal” range. For comparison, at road speeds I am at r/m, right in the
middle. At a stop light, it may move up to a full m. Caught in traffic,
my main efan goes on at m+, and temp will continue to rise to a or
a/l. The aux fans then come on, and temp will stabilize and may actually
reduce back down to a. Is this normal? Thanks.
Dave
79 XJ6L SII
Hey Larry, I remember those long, long, downhill entrance ramps on the
interstate between Dallas & Austin – just go up one, instead of down. :]–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.
Larry Karpman wrote:
In reply to a message from Cannara sent Mon 10 Jun 2002:
OK Alex, pack up one of those Northern California hills and send
here to the flatlands of Texas and I’ll try it
One thing I did note on the 80 mile trek today was that the temps
made no difference with a/c on or off. In fact, I’m convinced it
ran a degree or so cooler with the a/c on. Probably just a mirage
from staring at the gauge for 80 miles.
David, on ours, in mild weather (70F), the gauge never went beyond the RM
junction when moving along, but not climbing hills, etc. This was with no
shroud or clutch fan. You may want to set your efan to come on a bit earlier,
just to be sure the right half of the range gets forced cooling. Since there
are 2 aux fans, they make a big difference when on, so a little earlier on the
main fan will save them wear.–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.
David Spalding wrote:
At 10:38 PM 6/9/02 -0700, Cannara wrote:
With the OE fan & shroud removed, the car should cool
itself at 30 mph or higher, with aux fans only coming on when idling at a
light.
Alex, or any other SII owner-
When this happens, what does the temp gauge show? All the posts have used
numerical values, but as you know, the SII has a gauge that only indicates
a “Normal” range. For comparison, at road speeds I am at r/m, right in the
middle. At a stop light, it may move up to a full m. Caught in traffic,
my main efan goes on at m+, and temp will continue to rise to a or
a/l. The aux fans then come on, and temp will stabilize and may actually
reduce back down to a. Is this normal? Thanks.
Dave
79 XJ6L SII
actually there is, since the A/C rad sits in front of the coolant
rad. With A/C on the heated air generated by the A/C rad will flow
through the coolant rad. This should only make a marginal difference
tho.
Actually there is not, Arnoud. The thermostat just opens a bit more to
keep things cool. That’s why it’s there?
Maybe the climate you live in permits that, over here you certainly wouldn’t
get away with it.
The cooling system of the XJ-6 is, for hot climates, marginal. This is shown
best looking at the slightest glitch causing engines in these climates to
overheat.
If you obscure a radiator with a device that when in operation gives off
heat, you diminish the effectiveness of that radiator. In the case of the
XJ-6 it clearly shows the point where the capacity of the cooling systems
falls short, and the operating temp of the engine rises a few degrees with
the A/C in operation. The capacity of the cooling system is used in full and
at that point the generated heat exceeds the point where exchange between
the rad and the air flowing through is sufficient.
When all other systems are 100%, operating the A.C under those conditions
should not be a problem and keep the operating temp of the engine within an
acceptable window, beit slightly higher than normal/ideal.
IMO Arnoud was spot-on.
Cheers!
Jack Verschuur/ Durban, South Africa
Autowood Africa www.radial.co.za/autowoodafrica
'66 Mk2 3.8 MOD
'67 420 MOD
'68 or '69 420G auto
Autowood Africa wrote:
Actually, Frank, I’d hope by the time the aux fan kicks in the
thermostat
would be fully opened.
We were talking about A/C influence on temp, Jack. Actually if your aux
fans kick in, your cooling system is not working properly, or else I’m
deep in s…- I haven’t got them…
Maybe the climate you live in permits that, over here you certainly
wouldn’t
get away with it.
The cooling system of the XJ-6 is, for hot climates, marginal. This is
shown
best looking at the slightest glitch causing engines in these climates
to
overheat.
If you obscure a radiator with a device that when in operation gives
off
heat, you diminish the effectiveness of that radiator. In the case of
the
XJ-6 it clearly shows the point where the capacity of the cooling
systems
falls short, and the operating temp of the engine rises a few degrees
with
the A/C in operation. The capacity of the cooling system is used in
full and
at that point the generated heat exceeds the point where exchange
between
the rad and the air flowing through is sufficient.
When all other systems are 100%, operating the A.C under those
conditions
should not be a problem and keep the operating temp of the engine
within an
acceptable window, beit slightly higher than normal/ideal.
I’m a proponent on the marginal cooling of the xj6, Jack, and have been
duely chastised on that subject on several occations
Compared to effects of ambient temp and load the A/C effect is minimal.
The temp will not increase with A/C on, EXCEPT when the cooling capacity
is driven beyond its limits by other factors anyway. To blame the A/C is
rather futile. But it is not a well cooled engine…?
