How to Determine the Shelf Life of Car Antifreeze

gallon of antifreeze on a car engine
What You'll Need
Testing strips
Pair of rubber gloves
What You'll Need
Testing strips
Pair of rubber gloves

Car antifreeze is used to lower the freezing point of the fluid in your car to prevent it from crystallizing and freezing in extreme cold. It also functions to keep the engine from heating up by raising the boiling point of the liquid, it also deters formation of corrosion and scale within your car engine. An average blend of 50% to 80% car antifreeze and water is added to the radiator for efficient functioning of the car antifreeze.

Step 1 - Know the Shelf life of Antifreeze in General

A sealed can/bottle of antifreeze has an indefinite shelf life. The new non silica extended antifreeze when opened has a shelf life over eight years. Antifreeze is hygroscopic, which means it absorbs water, therefore if you keep it air tight you will not have a problem. When antifreeze is put in a car and mixed with another fluid, that’s when it starts to degenerate, even then car antifreeze has a very long shelf life. You can follow the following steps to determine the shelf life of your car anti freeze and whether it needs replacement or not.

Step 2 - Check the Overflow Container

Most cars have an opaque overflow container. Check the levels of antifreeze in the car by reading the graduations on the container, and if it falls below average you need to add more.

Step 3 - Slush the Fluid in the Radiator

antifreeze reservoir in an engine

If the fluid in the car starts to become slushy in winters, it means that the anti-freeze is dead. This will have several effects. One reason for this can also be that the ratio of antifreeze to water is not proper. Check whether the fluid is slushy.

Step 4 - No Heat in the Car

Despite having antifreeze in your car if the car does not heat properly, it means that the antifreeze is dead and needs to be flushed out and replaced with new antifreeze. Dead antifreeze means the antifreeze quits being effective, which means it can no longer protect your engine from corrosion, boiling over or freezing.

Step 5 - Formation of Corrosive Deposits

If dead antifreeze is allowed to sit in the car for a long time, corrosive deposits will start developing. If antifreeze is not changed, this can lead to other problems and an expensive repair job.

Step 6 - Use a Tester to Measure the Specific Gravity of the Antifreeze

antifreeze in an engine

Tester strips are available in the market; these are used to measure the specific gravity of antifreeze in your car. Most mechanics use the very same strips; these are relatively inexpensive and will tell you within minutes whether the shelf life of your car antifreeze is over and needs replacement. These strips come with a step by step procedure; follow it to determine the SG of your car coolant. Remember to wear gloves while testing in order to protect your hands from any damage.

Step 7 - Car Maintenance and Fluid Replacement

Its best to change your coolant bi-annually, otherwise you can go up to two years without changing the antifreeze, any duration more than that might result in unexpected freezing or boiling over of your engine depending on the weather. As a rule, 30,000 km should be the limit, after which you should change your coolant, if you use your car regularly.