Keith and Bob,
You might find the following information of interest. It is from the
JagLovers Forum dated 30Jun2004. Written by: Craig Talbot
<talbotc@telus.net>
Over the last few years my E type has been running warmer and warmer,
until last year it really wasn't driveable when the temperature was over
the high 60's. The temp gauge would head over to 90, the fan came on and
it would stay there pretty much regardless of what I did. It would also
run quite rough at that point, so I know that it wasn't happy.
After cleaning the radiator in my Vandan Plas, I hit upon the idea of
cleaning the entire cooling system in the car from the inside. I figured
that the radiator and block was probably plugged with minerals (we have
hard water) and that was impairing the heat transfer. My solution was to
dissolve the minerals and have a clean motor and radiator. I tried a few
of the commercial "rad flush" solutions, and found them all equally
inert, so I started thinking about a DIY solution. Acids dissolve the
calcium deposits quite nicely, so I thought about various acids to use.
Fortunately, my Mom works at the University and her boss is a Ph.D. in
Chemistry, so I asked him. He said not to use a strong acid, such as
hydrochloric or sulfuric acid, as it will eat the aluminum head, so
things like CLR were out. He recommended acetic acid (vinegar), but with
the caveat that it will react with glycol, so all the anti freeze must
be well flushed first. I thought about buying a gallon jug of vinegar,
but it is mainly water and less than 5% acid. Instead, I went to a photo
supply and bought Kodak 28% acid, intended as a stop bath for film and
paper processing.
I drained my anti freeze, and flushed the system with water to get as
much antifreeze out as possible. I then added the 16oz bottle of acid to
a gallon bucket of water and poured that into the radiator, then topped
the rad up with water. I ran the car until hot, and let it sit for an
hour or so, then drained the acid out. It's important to have both the
block and radiator drains open, as I got a lot out of the block drain
after the rad came clean. I put a pan under the drains to catch the
acid, and what when in clear came out looking like chunky milk. There
were so many minerals that they settled out in a 1/2" thick layer in the
drain pan after it stood for a while!
Once the acid was drained, I filled the system with water to flush more
minerals out, and to remove the acid. I repeated a few times to make
sure the acid was gone, then replaced the antifreeze. So far the car
runs much cooler, and is smoother. Generally it will stay right at the
thermostat temperature without the fan running, unless I get stuck in
traffic. Then the temperature will rise, but once things start moving it
will cool down again, whereas before it would stay hot. This procedure
made a big difference to the car, and was well worth spending $4.99 on a
bottle of acid.
Alan Schultz
67HBJ8
53 Jag MK VII
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