Those who have experienced it (overheating) before will definitely
tell you that it is one incident that they don’t pray to witness again.
OVERHEATING is one word that has been on the lips of many people, it
doesn’t knock before sweeping right through and when it does come in, it
can be very tricky to diagnose.
Now for the benefit of those who have not witnessed the scenario before, I will give a quick description of what overheating is.
Overheating is a condition in which your engines temperature rises to
a very critical level, usually above the middle of the gauge and
towards the red line. It arises as a result of a problem in the cooling system.
There are a whole lot of things that can cause overheating but
we will be treating only one in this article, other causes will be
treated in subsequent articles.
The very first on the list of causes that i will be discussing will be low coolant.
In the cooling system article, I discussed about coolant and its importance.
It is the lifeblood of the cooling system as it is the one that
absorbs the heat from the engine. In a case where you have insufficient
coolant, then the efficiency of the system is reduced and when this
happens heat absorption becomes low thereby leaving this heat to build
up in the engine.
A low coolant level can be caused by a leak either external or
internal or from outright carelessness, although the latter is not all
that common.
An external leak in the cooling system will be found around areas
like the water hoses, the water pump, a leak in the radiator, or can
even come from a leak in the coolant reservoir.
Sometimes a bad radiator cap will also result in this because it can
no longer hold pressure so the coolant will keep flowing freely into the
reservoir.
An internal leak will be a little more difficult to diagnose because
it’s something you cannot see and it could be coming from anywhere in
the system.
One good way to know that you have a leak is when you have to top
your coolant every day. The very tricky thing about a leak in the system
(especially an external leak) is that you will not notice the leak.
This is because the leak will only occur when the system is under
pressure (except it is a very big one) and this pressure will be
achieved when the engine is hot and coolant like any other fluid will
evaporate at that temperature.
So what you will have is a case where as the coolant is leaking out
it is evaporating and this is what at times confuses most mechanics and
DIYs. Now someone must be wondering –“if I need pressure to detect the
leak and I can’t do it while the engine is hot, then what do I do?”
Its pretty simple –a cooling system pressure test.
Those who are conversant with the radio program would have heard this
phrase a couple of times. It is an automotive test that involves
pressurizing the cooling system to a certain pressure, so as to simulate
a driving condition.
When this happens it becomes easy to detect whether there is a leak and where it is coming from.
Coolant leak is just one of the many causes of overheating and now
you know that checking your coolant is very important. When next you
have an issue of overheating, you can go ahead to perform the test on
your vehicle.
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