Coolant – protecting your engine beyond the heat and cold

Coolant – protecting your engine beyond the heat and cold
Coolant – protecting your engine beyond the heat and cold

Coolant - protecting your engine

Engine fluids

For more information on coolant recommendations, as well as other engine fluids, check the Perkins Fluid OMM.

Perkins Fluid OMM


Coolant – protecting your engine beyond the heat and cold


Coolant’s use to keep your engine at the correct temperature is well known, but did you know it has many other benefits?

Coolant serves as a carrier for additives such as pH stabilisers, anti-foaming agents, and protection agents for rubber and plastic components. It also inhibits corrosion and protects against cavitation and cylinder pitting.

Using water or the wrong type of coolant puts your engine at risk.

Corrosion prevention

Diesel engines fall into three types:

  • Parent bore engines where the cylinder block is one piece
  • Dry-sleeve or liner engines, where a liner is inserted into the block – typically found in automobile engines with aluminium blocks
  • Wet-sleeve or liner engines which allow the sleeve (that contains the piston) to come in direct contact with the coolant. Wet sleeves allow more heat transfer than dry systems and are often found in larger diesel engines such as the Perkins® 1700 Series, 2000 Series and 4000 Series engines

Wet-cylinder diesel engines transfer a lot of vibration and movement from the pistons to the cylinder walls and this can create coolant cavitation (tiny bubbles) behind the cylinder walls. Cavitation can lead to pitting in the cylinder walls. The correct coolant can protect your engine by forming a barrier between the liner and these bubbles. 

It’s also important to use a high-quality coolant to protect the metal in your engine from corrosion. It is common to find six basic metal alloys within the engine’s heat transfer system: copper, solder, brass, steel, cast iron and aluminium. All of these can corrode on contact with water, so water-based coolants need suitable corrosion additives. Without this, corrosion can cause blockages within the narrow spaces of radiators, as well as thinning and failure of pipes, and damage to water pumps, thermostats and operating valves.


Coolant options

Coolants come in two major types:

  • Standard heavy-duty, fully formulated products
  • Long life or extended life coolants (LLC/ELC)

The main advantage of extended life coolants is that their service life is typically twice as long as double heavy duty fully formulated products, and they don’t require testing or the addition of corrosion protection additives. 

Perkins® Extended Life Coolant helps you manage service costs and protect your engine.

Benefits of Perkins Extended Life Coolant include:

  • Lasts at least twice as long as conventional coolants. Perkins ELC will last for 6,000 hours or three years
  • Pre-mixed 50/50 coolant with purified water formula, eliminating the need to source de-ionised water
  • Ensures the correct ratio of mix is maintained for top up
  • Avoids the need to top-up with supplemental coolant additives (SCAs)
  • Advanced formula technology with organic additive corrosion inhibitors
  • Practically eliminates hard water deposits and extends water pump seal life

Learn more

Your maintenance regime should match the coolant your are using

Heavy duty coolants

Because corrosion inhibitors in heavy duty coolant are used up over time, this type of coolant must be tested every six months or every oil change to check if corrosion additive needs to be added.

To make this easier, you can buy test strips to use in the field, but beware - use of the wrong strip can result in incorrect results and improper dosing. Test strips themselves also have a shelf life.

If you find your engine’s additive levels aren’t correct, they must be restored with the addition of a corrosion inhibitor which meets your engine and coolant manufacturer’s specifications. 

Extended life coolants

Extended life coolants, such as Perkins® Extended Life Coolant last longer than heavy duty coolants. They do not require corrosion inhibitor testing but you do need to keep track of coolant levels to ensure they are correct.

Regardless of the type of coolant you are using, we recommend you check levels frequently, following your engine’s operation and maintenance manual

Which is best, heavy duty or extended life coolant?

Both types of coolant will protect your engine, and testing and maintaining additive levels is not the hardest action, but why bother if you don’t have to?

Extended life coolant cuts waste which helps your pocket, the environment and you, as disposal requirements have become more stringent and costly in recent years. Disposal of used coolants can be difficult and expensive and must be done in accordance with local or national laws. It’s also easier to manage, only requiring occasional top-ups.