Hello everyone
I’m in the very final stages of engine assembly after a
winter restoration to cure high oil consumption and have
encountered a problem. I’ve filled the radiator with 50%
antifreeze and have a leak coming from the head gasket at
the rear exhaust side, seems about a drop every hour or two.
I can feel the wetness behind the rear manifold at the
head/block junction and see the trail of the leak down the
side of the engine, it collects on the ledge below the drain
tap. I initially thought the tap was the problem but
unfortunately not. Core plugs are dry.
The auto engineers I used for the head and block work
checked the head for trueness and returned it to me clean
and polished. I used Payen gasket sets and fitted the head
gasket dry, I understand they are coated with a varnish that
melts and seals. I torqued the head by the book. I have
refitted several cylinder heads in the past, including this
one a few years ago, without problems. I have at times used
a sealant on both sides of the head gasket as ‘insurance’
but don’t think I used it on this one the previous time and
had no coolant leak problems.
The question is do I take off the head to see if there is am
obvious problem and refit with a new gasket or do I risk
starting the engine, run up to temperature if nothing
drastic happens, retorque and hope the varnish does its work.
Any advice is most welcome.
Ken
Morpeth, Northumberland.
1969 2+2–
etyper
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from etyper sent Sat 19 Mar 2016:
Ken,
First item is to add a container of the original Bars Leaks
to the coolant, as the factory did. You hear all sorts of
disparaging stories but if you use it according to the
instructions it works fine without problems. When I last
got my engine rebuilt I had a small leak at one of the head-top plugs, and the
top plugs, and the builder recommended this. Leak fixed ve
very quickly and no problems since. What the factory re
recommends is best, I think.
Jerry–
Jerry Mouton '64 FHC 889791 ‘MIK Jaguar’
Palo Alto, California, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from mouton sent Sat 19 Mar 2016:
Interesting suggested solution from Jerry. Would not have
thought a properly prepared block & head would have a static
leak like described. I am using the same type of head gasket
and hope not for the same problem.–
Dales 1970 E-type OTS
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from etyper sent Sat 19 Mar 2016:
Hi Ken,
I suggest you retorque the head gasket by loosening each nut
and retightening it to specified torque, starting in the
correct order.
Then see if it still leaks.
If it still leaks, and if it were my engine, I would drain
the water out and take the head off and recheck both the
head and block for trueness.
And I would then reassemble with a NEW headgasket (as it
might be there was a problem with the old one–
Dennis Vancouver Canada 69 Roadster
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Dennismo sent Sat 19 Mar 2016:
I had the same problem…guess what …after a few warm
ups the leaks stopped…I highly recommend not taking the
head off at this point…stop leak is a valid choice
also,it works…this is not as big a problem as it seems
to be…–
Pjwilletts 62 ots, 60 Bugeye sprite
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from etyper sent Sat 19 Mar 2016:
Hi Ken, I have just refitted the cylinder head on our XJ6
after a valve service and a ‘‘clean up’’ skim. We have a
long stud engine - all studs changed out as well. My
engine builder advised me that I might experience a bit of
weeping up through the head studs and perhaps elsewhere
before the head seals and settles properly. I have to
admit as soon as I filled it I stared it - so don’t know
if it might have leaked had it remained unstarted and cold
for an extended period.
As you did I applied the Payen gasket without sealant.
Long stud engines have more opportunity to leak, of
course, compared to the earlier short stud engines.
As Jerry said I was advised that the company used up to
two cans of Bars Leaks as part of engine build and
commissioning. My builder offered me a can to manage any
leaks - in my case not required - yet! Good luck, Paul–
The original message included these comments:
encountered a problem. I’ve filled the radiator with 50%
antifreeze and have a leak coming from the head gasket at
the rear exhaust side, seems about a drop every hour or two.
I can feel the wetness behind the rear manifold at the
head/block junction and see the trail of the leak down the
side of the engine, it collects on the ledge below the drain
–
Paul Breen
Sydney '62 E FHC, '72 ,XJ6 swb, Australia
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Breen60 sent Sat 19 Mar 2016:
Hi, I would make sure that the insides of the head dome nuts
are not bottoming out before you reach the correct torque.
Look for any witness marks inside the domes and on top of the
studs, one at a time, as you retorque the head.
Regards,
Allen–
alodmd
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from alodmd sent Sat 19 Mar 2016:
The freeze plus tend or do leak…sure it is not a freeze
plug and if it is use Bars…as has been recomended–
Mitchell Roe
Hasty, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from etyper sent Sat 19 Mar 2016:
Thank you for your replies to my leaking head gasket
problem, I am very grateful. I’ll ponder your advice over
the next couple of days before deciding which way to go.
Many thanks
Ken–
etyper
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from etyper sent Sat 19 Mar 2016:
When we build engines we don’t put anything into the radiator
until after we have run the engine.
What we then do is to spin up engine on the starter with no
spark plugs in, until the oil pump primes and we have oil
pressure. Then the plugs go in and we stat the engine up and
run it for a couple of minutes or so.
Only once that is done do we put WATER only into the radiator.
The engine then gets a run up to operating temperature, is
tuned etc. In the past we have routinely used Bars Leaks at
this point although now woe do not.
Only at this point do we put coolant in.–
The original message included these comments:
encountered a problem. I’ve filled the radiator with 50%
antifreeze and have a leak coming from the head gasket at
In reply to a message from abowie sent Mon 21 Mar 2016:
What is the thinking with that?
I recall some water pumps like to run dry for a bit
(possibly a carbon bearing) but never heard of omitting all
coolant/water for an engine start-up.–
The original message included these comments:
When we build engines we don’t put anything into the radiator
until after we have run the engine.
–
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 Geo H sent Mon 21 Mar 2016:
So water doesn’t go into the engine if the head gasket leaks
initially for some reason. Gives the sealant on the gasket some
time to work.–
The original message included these comments: