With the temperatures plummeting and the weather worsening it is more important than ever that you have your antifreeze tested and/or renewed.
Note: Don't confuse antifreeze (which goes in your car radiator) with screenwash (which goes in your screenwash bottle)!
Antifreeze is made of the chemical glycol - often known as coolant in its diluted state, which is usually half glycol and the remaining water. Traditionally antifreeze is made with ethylene glycol, however recently a 'safer' version of glycol called propylene is now commonly used.
ETHYLENE GLYCOL - This substance is extremely poisonous; the consumption of as little as two tablespoons of the liquid can be fatal for vulnerable people i.e. young children & pregnant women.
PROPYLENE GLYCOL - Often known as the safer substitute to ethylene glycol, although it is still toxic it is significantly less harmful than the traditional counterpart.
Antifreeze has a lower freezing point than water, preventing the water in your vehicle from freezing under extreme conditions. However, equally important are its anti-corrosive properties which prevent corrosion to vital engine components i.e. the radiator. Without having anti-corrosive protection, the engine components will rust and over time cause catastrophic damage with a repair price-tag that reflects this.
ANTIFREEZE RENEWAL & MAINTENANCE
You should regularly monitor the coolant level and quality, in order to gain an accurate reading the level should be checked when the vehicle is absolutely cold i.e. in the morning before you make any journeys. If your coolant level is slightly low it is safe to top up with water to the correct level without having a drastic effect on the antifreeze properties. However, if the level is considerably low it is advised to add the appropriate amount of antifreeze also. If you have an extensive drop in the coolant level you should refill with water to prevent the engine overheating and take the vehicle to your local garage as soon as you can for further investigation and to diagnose why the vehicle is using or losing coolant.
It is strongly advised that you have your antifreeze renewed every 2 to 3 years. An antifreeze renewal will consist of draining the existing fluid, refilling with a mixture of glycol and water and then vacuum bleeding to remove any air in the system - it is essential to have the system bled correctly to prevent air pockets moving into the water jacket causing the engine to overheat. The mixture of glycol and water should be about 50/50, however if the antifreeze level is substantially higher than the water content it can have an adverse effect on the anti corrosive properties. If you are ever required to remove the radiator cap you should never remove the cap whilst the engine is hot, always wait till the engine is cold.
You are also recommended to have an antifreeze flush carried out on your vehicle every second antifreeze renewal, approximately every 4 to 6 years. This usually consists of draining the existing fluid, refilling the system with a flushing agent (alkaline chemical), draining the system and then carrying out an antifreeze renewal. It is advised you have the antifreeze flush as the system can become highly acidic which can cause damage to your cooling system, thus flushing the system through will neutralise the system.
DISPOSAL OF ANTIFREEZE
Great care must be taken when disposing of antifreeze due to its toxicity. Antifreeze should never be poured down household drains or into sanitary/storm sewers. If carrying out your own antifreeze renewal, most communities have procedures to dispose of hazardous waste so use these to your advantage, if in any doubt consult your local authority or take your vehicle to your local garage to have the renewal carried out.