What is diesel engine coolant? Why is it useful? Why is it important? Why not use water?

Diesel engines do a lot of work, they are in many cases the work horses of portable and stationary equipment when an electricity supply isn't available, or in the case of diesel generators providing the electricity supply!

In order to keep equipment reliable and maintain it for the long term correct lubrication oil and engine coolant should be used.

This varies between engine manufacturers for both oil and coolant. Typically coolant is recommended to be a mix of 60% glycol and the balance demineralized water. For leading engine manufacturers this recommendation changes to their own products, which offer superior corrosion resistance by the addition of extra compounds to the coolant. Perkins Engines for example recommend the use of Perkins Extended Life Coolant (ELC), which comes with supplemental coolant additives (SCAs) already added and therefore no additional additives are required.

Yellow/Orange in colour, the Perkins ELC stands out from the traditional blue coolants - but beware! Manufacturers of coolant are increasingly producing it in many different colours and just because its the same colour, that doesn’t mean it will protect your engine.

Perkins ELC offers significantly extended service intervals, which will mean reduced costs. Other engine manufacturers also produce their own individual versions which will also mean a saving in the pocket over the traditional blue coolants you can buy off the shelf.

Coolant itself is superior to water in terms of operating conditions. In freezing weather conditions, the coolant won't freeze and can circulate effectively through the system to cool the engine and prevent damage. In hot weather and when the equipment is being operated at peak load for long periods, the coolant will resist boiling and continue to circulate as a liquid, effectively cooling the engine.

Coolant matched to the application is critical to prevent corrosion - poor or out of specification coolant or coolant without the SCA added will corrode components - often very fast and lead to radiator leaks and failures of the cooling system. Often the protection devices like the coolant level switches, coolant temperature switches or coolant temperature senders will corrode in the coolant flow.