Vehicle Maintenance, Auto Parts and Coolants

Introduction to Vehicle Coolants

Vehicle coolants are important for vehicle maintenance and safety irrespective of the climate. An antifreeze mixture lowers the freezing point of the cooling system in winter. It also raises the boiling point of the cooling system in summer.

For most of the “not so technical” vehicle owners the choice of the vehicle, coolant is left in the hands of the vehicle workshop and mechanic. Our failure to comply with the OEM specifications and requirements could lead to unnecessary and expensive maintenance costs.

It is important to recognize that the number of different motor lubricants and coolants available to consumers have multiplied exponentially as the motoring industry tries to keep up with the lubrication requirements of all the different vehicle manufacturers.

Why do we need to know more about Vehicle Coolants?

The cooling systems of modern vehicles have parts made from copper, silicon, nylon, steel, and magnesium and aluminium alloys. The type of coolant required by the vehicle can now vary by year, make, model, engine and even the country where the car was made.

With so many factors in play, car owners need to know which type of engine coolant is right for their vehicle.

Using the incorrectly specified coolant or low-quality coolant can lead to:

Head gasket failure
Liner pitting in diesel engines
Water pump failure/water pump seal failure
Damaged cylinder liner seals
Cylinder head cracks and holes
Destroyed welsh plugs, radiators and heater cores,
Other cooling systems components being eaten away.

What is the purpose/function of vehicle coolants?

The main task of the coolant is to transport the heat generated in the engine to the radiator and the interior heater.
Furthermore, the coolant increases the boiling point, protects the engine from corrosion and rubber/plastic parts from premature wear.
The removal of heat by the coolant in the cooling system enables the engine to operate in an efficient manner.
It lubricates the seal of the water pump and prevents the mixture from freezing.

What is the difference between Antifreeze and Coolant?

The correct term is "coolant additive" because the pure frost protection (= antifreeze) is only a partial task of the coolant.
The coolant increases the boiling point, protects the engine from corrosion and rubber/plastic parts from premature wear.
Antifreeze keeps the water in your radiator and engine from freezing in cold temperatures
It lubricates the seal of the water pump and prevents the mixture from freezing.

Can different coolants be mixed (different brands)?

It is not recommended to mix coolants with products of different specification and qualities.

Coolants from different manufacturers can only be mixed if they meet the same OEM specifications and standards.
HEPU coolants always meet OEM specifications and standards and can be mixed with OEM coolants and coolants of comparable quality.
Mixing of different specifications (and colours) is generally not allowed and can have serious consequences.

What do the different colours of coolants mean?

It is not an indicator of the type or quality of a coolant. Before dye is added, all coolant is colourless.
The colour of the coolant indicates the specification/quality standards of the product but does not have a technical function itself.
Car manufactures are using different colour as a marker to distinguish different qualities.

Is flushing of the cooling system necessary?

Thorough flushing of the cooling system is absolutely essential when changing the coolant.
The cooling system must be flushed as it is contaminated with rust, dirt or oil.
Flushing must be continued until only clear water without impurities runs out of the system.
If the cooling system is very dirty, special cleaning agents for the cooling system can be used (no household cleaners, etc.)

When should the Antifreeze/Coolant be replaced?

Old coolant must not be used again.

After draining, coolant must be disposed of properly and replaced with a new one.
The replacement interval for the coolant is specified by the car manufacturer.
However generally speaking after 5 years at maximum, the coolant should be replaced.

Can I use water instead of Antifreeze?

After a breakdown (e.g. a hose that has slipped off), it is possible to fill it up with clear water just to drive to the next workshop. But at the workshop, the system must be refilled with coolant again.
Most of the modern engines have cylinder heads comprised of aluminium. These aluminium cylinder heads require the anticorrosive properties found in your antifreeze.
In the long term, pure water must not be used in the cooling system, as this can lead to corrosion and defects in the water pump and other components.

Why can’t I pour coolant without diluting it?

Undiluted antifreeze has different chemical and physical characteristics than the right mixture.
Undiluted coolant dissipates engine heat even more poorly and freezes faster than the mixture in the correct ratio.
Nowadays there are also so-called “Ready-Mix or Ready-to-use” coolant qualities available.
These coolants are already premixed with demineralised water in the correct mixing ratio and can be used without adding additional water.
Premix coolants eliminate concerns around using hard water (high mineral content which can be harmful to the internals of the vehicles cooling system) with a concentrated coolant.
It also prevents incorrect mixing ratios as too much water increases rust corrosion and too much coolant leads to in-efficient heat transfer.

Remember Safety First when working on your vehicle!

Do not add coolant to a hot engine - wait until the engine has cooled down!
This will prevent burns and causing damage to the engine block.
Do not open the caps on either the coolant reservoir or the radiator while the engine is hot, even just to check levels.

When in Doubt - Ask the Experts!

When it comes to antifreeze/coolants, always use a reputable and endorsed product that meets the requirements stated in the owner’s manual of your vehicle.
If you notice that your antifreeze mixture has a sludgy or oily surface, be sure to immediately take your vehicle into a mechanic.
Consult with your mechanic about using a high-quality coolant product. Through following careful preventative maintenance practices, you can ensure the proper protection of your engine

A word of Appreciation to Goldwagen and HEPU Coolants for the assistance received.