Statistics
show that cooling problems are high on the list of
roadside complaints motoring organisations have to
attend to. Many of these problems can be prevented
by proper maintenance, and there is a lot more to
it than just making sure there is enough water in
the radiator.
Modern
engines need a good anti-freeze. The resulting mixture
is a cooling fluid that acts as a corrosion-inhibitor,
in addition to its ability to lower the freezing point
and raise the boiling point. The concentration should
be as specified on the container, and nothing will
be gained by adding more fluid to the radiator, but
it may be harmful if the mixture contains more water
than specified. It should be changed every 18 months
because the chemicals gradually lose effectiveness.
The
water level should be inspected every week; investigate
any unusual drop in the level. It may be an external
leak that you can fix by replacing a hose, or taking
the radiator to a specialist radiator repair shop,
or it may be a weak radiator cap spring or gasket.
It could also be a leaking cylinder-head gasket, but
in this case there would be some symptoms that you
should look out for. Bubbles arising from an open
radiator is one of the signs, and water in the oil
is another.
Fan
belt tension should be checked and adjusted, as discussed
elsewhere, while the fan blades are visually examined
for cracks, and the hoses examined for signs of cracking
and the soft feeling that comes with old age. On an
older vehicle, the Welch plugs, round steel discs
that cover inspection holes in the head or cylinder
block castings, should be checked for
signs of external rust. They tend to
spring a sudden leak, often with disastrous consequences.
Grass seeds, and other objects sticking to the radiator,
must be carefully removed from time to time.
 Many
people, even mechanics who should know better, tend
to remove the thermostat at the first sign of overheating.
The purpose of the thermostat is to
ensure rapid warm-up as well as to keep the engine
at a near- constant temperature, so it follows that
if it is removed engine wear will increase and the
fuel consumption will suffer, because both of these
aspects depend on the
engine being at its proper operating temperature.
Water
hoses should be examined (when cold!) from time to time.
A hose in good condition feels firm, but a hose on its
way out is soft and squelchy.
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