Christmas madness as car overheats after short drive…

by Sunday News Online | Sunday, Jan 7, 2018 | 1700 views

car overheats

Lovemore Mafukure

Overheating is a common problem. Overlooking simple things like checking coolant level in the radiator can cost you an engine.

For us to understand the causes of overheating we would need to understand how the cooling system works.

The cooling system consists of a radiator, fan, water pump, and thermostat.

The radiator is there to cool the coolant and keep engine operating at optimum temperature. It draws or pushes air through the radiator cores thereby cooling the coolant.

Water as of old, has been the cooling agent of choice but overtime coolant has been developed and it’s better than water because it keeps the water lines rust free.

Water on its own corrodes the water lines, the radiator up-to the cylinder head. It eventually causes serious engine problems with blockages and leaks.

In cold areas, water can even freeze and coolant is used as an anti-freezing agent, it has a very low freezing point and very high boiling point.

The fan on the other hand draws air through the radiator core to cool down the coolant. The fan is supposed to come on at the right time every time otherwise the engine will overheat.

It is good to inspect the fans every now and then to make sure they are working. Some fans draw air though the radiator cores while others push air through the radiator core to keep the coolant cool.

For the coolant to circulate, the engine makes use of a water pump. The water pump is essential for the cooling system and without it the coolant will not complete its cooling cycle.

Water-pumps like most parts, have a lifespan. It is recommended to change the water pump every 100 000km when you change the timing belt.

Somehow it makes sense to change it then because in most cases to remove the water pump you have to remove the timing belt. We call it hitting two birds with one stone. It only makes sense.

To operate efficiently, engines have to reach a certain temperature. By use of a thermostat, the engine cuts coolant circulation to the radiator so that the engine warms up quickly and maintains an optimum operating temperature.

Thermostats wear out over time for various reasons. Use of water in the radiator causes rust in the cooling system and since these are metallic objects they rust away and typically for thermostats, they get stuck closed and when they are supposed to open, they will remain closed, cutting out circulation to the cooling radiator, ultimately causing the engine to overheat.

Some clever mechanics reckon it is wise to remove the thermostat and do away with it. It might seem like a wise idea at first but in the end, it proves otherwise. Firstly, removing the thermostat means the engine will run a lot cooler than normal.

Removing the thermostat retards performance and increases fuel consumption. A cool engine runs rich. For as long as the engine is cold, the engine computer will enrich the fuel mixture as the assumption is that the engine is trying to warm up. Running a cold engine also reduces engine life, an engine has to operate at the correct temperature. So, some clever ideas aren’t always clever in the long run. They say short-cuts are often wrong cuts.

Coming back to the question, it’s never easy to ascertain where the problem is coming from. It would be like throwing bones and doing some alakazam abracadabra stunt which does not work with cars, but given the background of the cooling system we can then ask a few questions . . .

Did you drive the car with no coolant or at least water? Does your radiator leak? Does your radiator cap hold pressure? Are your fans working as they should? Is your water pump working? Are you using coolant or water in your radiator? Lastly, is your radiator clean?

If any of these are correct in your case, the odds are high you may have a blown head gasket . . . you can smile at this point because it could be worse.

Your cylinder head may be warped, meaning its surface is not flat anymore.

The surface may be corroded as I mentioned earlier that water corrodes the cooling system over time. The corrosion may cause leaks that lead to overheating. Worst-case scenario is a cracked head or block due to excessive heat, if that is the case you may want to pull out that emergency fund.

-Disclaimer: This material has been prepared with the intent to provide reliable information; no warranty either expressed or implied is made to its accuracy or completeness.

No liability is assumed for any loss, injury to persons, property or other damage resulting from either the use of or reliance on the material presented. Always consult the professionals.

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Automart Spares & service Centre – Quality Japanese Salvage Parts & Auto Breakers

+263 772 33 99 38 – -@automart zw

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  • Willy

    How does this fit under sport column????