[v12-engine] Coolant contention?

Hi group,

(sad '72 XJ12 swb 1p1035)

I was just wondering what is the best way to clean my
coolant path ways. I’ve tried the bottled flush products
with no luck.

As it stands: - the car looks to me that it has been run on
plain water (grr!). There is a tick coating of rust
powder/sludge.

So my real question is this: Can it be cleaned 1) without
sending it to be chemically dipped 2) and with out removing
it from the car.

I plan to remove all steel. copper/brass, parts from the
cooling system. As I had been led to believe that copper &
aluminum causes a battery affect. (any electronic experts is
this right?) Finding replacement parts for the fiddly bits
might be hard, but radiator & heater cores shouldn’t be too
hard to get manufactured. (any ozzy out the that know of a
good place)–
Mark
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

In reply to a message from Veeateme sent Wed 21 Nov 2007:

As a matter of course, I flush my cooling system every 2 years or
so. The purpose being to head off any problems with the cooling
system. I use GM ‘‘Heavy Duty Cooling System Flush’’. It’s a 2 part
cleaner…concentrated Oxalic acid (part 1) and a neutralizer (part
2), and it works VERY well at removing/dissolving any rust/sludge.
If the directions are followed, and the cooling system is refilled
with a 50/50 mix of antifreeze/DISTILLED water, the system will
operate as designed with no cooling problems, and remain clean.
There really is no need to replace all the dissimilar metals which
come in contact with coolant. The electrolytic reaction you’re
refering too is non existant…otherwise, the aluminum head would
dissolve in no time. The flushing/refilling procedure every 2
years is cheap insurance against cooling system failure…which is
what I assume you’re after…–
The original message included these comments:

I was just wondering what is the best way to clean my
coolant path ways. I’ve tried the bottled flush products
So my real question is this: Can it be cleaned 1) without
sending it to be chemically dipped 2) and with out removing
I plan to remove all steel. copper/brass, parts from the
cooling system. As I had been led to believe that copper &
aluminum causes a battery affect. (any electronic experts is


345 DeSoto
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

In reply to a message from Veeateme sent Wed 21 Nov 2007:

Hi Mark,
What a grreat car. Your’s must be one of the earliest XJ12s.

When I pulled the heads off of my 74 last year, I was amaized by
the amount of sand, dirt and debris from the decaying head gaskets
in the water jacket surrounding the cylinder liners. I think some
of that stuff was in there from the factory. With the heads off, I
was able to completely clean out the passages. I had the rad
recored and replaced the water pump. I then installed a second
temp gauge sender into the B bank thermostat housing and connected
it to a SunPro gauge placed in the glove compartment / dash cubby.
The engine simply will not overheat, It stays at 88 degrees C no
matter how hot the ambient temp is or what the running conditions.

Flushing will certainly help somewhat, but I’m afraid you’ll never
get all the crud out of the water passages without pulling the
heads. The good news is that, with the open deck design of the Jag
V12, you have great access to the water passages after the heads
are off if/when you decide to go that far.–
The original message included these comments:

(sad '72 XJ12 swb 1p1035)
I was just wondering what is the best way to clean my
coolant path ways. I’ve tried the bottled flush products
with no luck.
As it stands: - the car looks to me that it has been run on
plain water (grr!). There is a tick coating of rust
powder/sludge.
So my real question is this: Can it be cleaned 1) without
sending it to be chemically dipped 2) and with out removing
it from the car.


John Testrake 74XJ12L rhd, 86 XJ6
St.Louis, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

In reply to a message from John Testrake sent Thu 22 Nov 2007:

Thanks everyone,

took my rad to the cooling experts where I live they do lots
of the local Jag communities fixing… anyway they go with
your idea John heads off. As for using chemicals, they don’t
suggest it as the alloy of older cars is a lot softer than
the newer cars (just their opinion) They also said and
showed me the current that is in the coolant of these older
style car then told me that if we used a alloy core it would
electrolyte away and rupture. So they measured up and gave
me a quote, Remove old tanks stripping and cleaning, and a
modern CT core put between the old tanks. They pressure test
my old rad to 14psi while I was there and there was a lot
of creaking then water water every where like a toilet in a
primary school— 8-)… Damage to back wallet = AUD$870

ouch, but half the cost of a alloy rad.–
Mark
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !