Since re-installing the car I am down to the cooling system.
I have very near four gallons in the system now but the temp
indicator still shows to the hot (red) after the car has run
for a bit. I have replaced, and checked the thermostat on a
hot plate and it is functional. The fans are working
through a jumped wire keeping them on all the time. Using
an infra-red thermometer: Water pump outlet temp 145deg,
135deg at the top and in front of the thermostat, 165deg at
the back side of the thermostat and on the intake manifold.
It is very likely there is air trapped in the system,
especially in the intake manifold.
How do I get the air to be displaced by the coolant?
I have also drilled a small hole in the top of the
thermostat as recommended by others on this forum.
I am thinking of disconnecting the top hose at the radiator
and attempt to fill the intake manifold manually while the
car is off.
Any other helpful tips/tricks is appreciated.–
Dave // 1971 OTS SII 2R13762
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from F18driver sent Wed 9 Nov 2016:
It is possible that everything is fine and your temp sender
or gauge is misleading you.
What do the fans do when not jumpered? IOW, do they come
on somewhat above mid-gauge and eventually bring the
indicated temp down?–
The original message included these comments:
an infra-red thermometer: Water pump outlet temp 145deg,
135deg at the top and in front of the thermostat, 165deg at
the back side of the thermostat and on the intake manifold.
–
Geo Hahn 1969 OTS 4.2
Mt Lemmon, Arizona, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from F18driver sent Wed 9 Nov 2016:
Although drilling a small air bleed hole in the thermostat
is not a problem, the Series 2 cars have a small hose going
from the thermostat housing to the radiator that bleeds the
air. Some of the Series 2 cars can be hard to get all of
the air out of the system. Jacking up the front of the car
helps. Leaving the flat cap on the radiator and leaving the
header tank open will let the air be pushed out of the
system during warm up and then it will suck back coolant
during cool down. I believe you have a 180 degree
thermostat which should not fully open until 180 degrees.
It will open some which is why it is getting hot on the
radiator side but not as hot as the engine side. Looks
normal. You might have a bad sending unit or gauge.
Infrared thermometers are really a boon to diagnosis in the
car world.–
The original message included these comments:
How do I get the air to be displaced by the coolant?
I have also drilled a small hole in the top of the
thermostat as recommended by others on this forum.
I am thinking of disconnecting the top hose at the radiator
and attempt to fill the intake manifold manually while the
car is off.
Any other helpful tips/tricks is appreciated.
–
Dick Maury , Rebuild Dept.- Coventry West
Lithonia, GA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
There was no point in drilling a hole in the thermostat. Even if the
thermostat didn’t have a bleed hole, there is a bleed passage in the
thermostat housing, which is what the small hose to the radiator is
there for. You don’t have air in the system. You have a bad gauge or sender.
Mike Frank
At 06:27 PM 11/9/2016, you wrote:>Since re-installing the car I am down to the cooling system.
I have very near four gallons in the system now but the temp
indicator still shows to the hot (red) after the car has run
for a bit. I have replaced, and checked the thermostat on a
hot plate and it is functional. The fans are working
through a jumped wire keeping them on all the time. Using
an infra-red thermometer: Water pump outlet temp 145deg,
135deg at the top and in front of the thermostat, 165deg at
the back side of the thermostat and on the intake manifold.
In reply to a message from Dick Maury sent Wed 9 Nov 2016:
Thanks Dick. I also thought the air would bleed through the
smaller hose, and perhaps some of it has, if not all. I
also thought of jacking up the front of the car to help the
process.
On the drive home I realized the heater valve has been
closed during the process. That part of the system was dry
as I checked the core for leaks when the car was pretty much
disassembled. So I think if I open the valve (turn the heat
on) while the engine is running I should get more flow
through the whole system.
I will change out the sending unit before I fire it up next
time.–
The original message included these comments:
is not a problem, the Series 2 cars have a small hose going
from the thermostat housing to the radiator that bleeds the
the air out of the system. Jacking up the front of the car
helps. Leaving the flat cap on the radiator and leaving the
header tank open will let the air be pushed out of the
normal. You might have a bad sending unit or gauge.
–
Dave // 1971 OTS SII 2R13762
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Geo H sent Wed 9 Nov 2016:
After I replace the sending unit… if that doesn’t solve
the problem…I will also change out the switch on the front
of the radiator as I am not positive it is working properly
either. Eliminating one problem at a time though…at least
I know the thermostat is functional!! The fans would never
come on no matter how hot the gauge read
Thanks for the input guys!!–
The original message included these comments:
What do the fans do when not jumpered? IOW, do they come
on somewhat above mid-gauge and eventually bring the
indicated temp down?
–
Dave // 1971 OTS SII 2R13762
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from F18driver sent Wed 9 Nov 2016:
‘’…The fans would never come on no matter how hot the
gauge read…‘’
Which could be a bad thermo switch or could be a faulty
gauge/sender. All three can be tested with a combination
of ohmmeter and/or pan of boiling water.
I’ll confess, I suggested the hole in the thermostat. In a
phone conversation David said that he was only able to put
3 gallons in the system. I have a similar car (S2) and the
aluminum radiator with a similar neck – I was unable to
get it to take that last gallon until I improved the route
for air to escape the head.
Yes, there is that small hose, a long nipple on the housing
and (as I recall) a little bobber-thingy inside the housing
– for me that was just too restrictive to effectively
clear the air. The radiator neck is about 1/4’’ higher than
that little hose - just wasn’t enough head to get mine to
take all the coolant. Dick’s idea of running the engine to
hot with the pressure cap off might have got it done though.
The extra hole does not seem to delay warm-up but then I
(and David) do not live in a cold part of the world where a
quick warm-up is especially desirable.–
The original message included these comments:
I know the thermostat is functional!! The fans would never
come on no matter how hot the gauge read
–
Geo Hahn 1969 OTS 4.2
Mt Lemmon, Arizona, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from F18driver sent Wed 9 Nov 2016:
I believe that my series 1-1/2 has the same system as a
Series 2.
I had to drain coolant when I changed the hoses to the
heater. I could not get fluid into the head until I released
the top hose into the heater radiator. The air came rushing
out and the system filled up with coolant. It still took a
couple of cycles to completely purge the air and obtain the
correct level in the overflow tank.–
The original message included these comments:
In reply to a message from Dick Maury sent Wed 9 Nov 2016:
Thanks Dick. I also thought the air would bleed through the
smaller hose, and perhaps some of it has, if not all. I
also thought of jacking up the front of the car to help the
process.
On the drive home I realized the heater valve has been
closed during the process. That part of the system was dry
as I checked the core for leaks when the car was pretty much
disassembled. So I think if I open the valve (turn the heat
on) while the engine is running I should get more flow
through the whole system.
–
'68 OTS : ‘03XJR I canna’ change the Law of Physics–Scotty
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Richard Kuschel sent Thu 10 Nov 2016:
Thanks Richard!!! I REALLY appreciate this response as it
confirms what I have been suspecting about that portion of
the system.
I also think it is likely that I have some other issues
too…first I will ensure fluid is flowing through the
heater portion of the system then investigate the sending
unit to the gauge and then the switch on the front of the
radiator.
In my mind I have to ensure the system is full, otherwise
the sending unit cannot be accurate. After I am sure the
system is full and most, if not all, of the air is out, and
the sending unit is functioning or not, then I can see if
the switch is functional…or not.
No time today as I had to ‘‘deposit’’ time on the domestic
home front…–
The original message included these comments:
heater. I could not get fluid into the head until I released
the top hose into the heater radiator. The air came rushing
out and the system filled up with coolant. It still took a
couple of cycles to completely purge the air and obtain the
correct level in the overflow tank.
–
Dave // 1971 OTS SII 2R13762
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from F18driver sent Thu 10 Nov 2016:
Had the same problem with my 1970 S2 FHC and by running the
car and releasing the top heater hose got the airlock to
shift and bled the system–
The original message included these comments:
heater. I could not get fluid into the head until I released
the top hose into the heater radiator. The air came rushing
out and the system filled up with coolant. It still took a
couple of cycles to completely purge the air and obtain the
correct level in the overflow tank.
–
Mike, UK - 1970 XKE S2 FHC
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
I believe that I am having the same problem. What do you mean by “the top hose into the heater radiator”?
Also, I have an aluminum rad with a radiator cap that seals at the bottom of the neck. Should I get a cap that just seals the very top?
Those temps are EXACTLY where they should be! You are NOT over-heating, your gauge is reading wrong. Either the sender, or gauge, is faulty. Replace the sender. If that does not solve the problem, the replace the gauge, or send it out for repair.
True over-heating will result in large amounts of coolant and steam being violently expelled through the over-flow. If that is not happening the engine is NOT over-heating, no matter what the gauge says.
Thanks Ray. During my engine out experience and doing a lot of “while in there” items I had replaced the sender unit. Apparently the version I received and installed required a different gauge (still not entirely sure why). I bought a new gauge and installed it…solid temp indication ever sense.
Hi Dave, I also drive a 71 Ser 2. (ser. no. 2R28477. My problem is at the other end of the spectrum though, my car runs cool, even with a 185 thermostat. In the fall and spring I blank of part of my radiator to get the needle to the center of the dial to get some heat in the car. I also have an oil cooler mounted in front of the radiator. So how did this all come about? An engine rebuild 18 k ago, a re-cored radiator, total flush of the system and a 50/50 glycol mix in the system. My fans work when required in hot summer/ traffic crawling etc. I also dumped the twin Stranglebergs for 3 SU HD’s, added a vapour trap to keep the air intake from the sump cleaner. It may seem like alchemy, but 39 years of being owned by “Sylvia” has taught me much.
