Monday, 29 August 2016

Engine coolant expiration date

My car's coolant is below MIN mark and I have coolant in the opened but sealed original plastic bottle. There is an expiration date but can coolant go off and how quickly? Can I use it?

Does engine coolant have an expiration date?


Antifreeze, premixed has an expiration date of 1 to 5 years when kept in the original container. Check the bottle carefully for a date, or shelf life.

Antifreeze, concentrate has an Indefinite expiration date when stored in the original container.

Once you put it in the car it does lose the ability to keep the water from overheating or from freezing in the engine when it gets old. Your owners manual should have the schedule when they suggest it be changed. I don't remember the interval that you need to change it. Ok I just checked and every two years is when you normally change the antifreeze in most cars. The antifreeze gets acidic when it gets old so it is important to change it so your engine and coolant parts don't rust and deteriorate. They do make a 5 year antifreeze so the changing interval would be longer. But in very severe climates changing it in three years might be wise even with a 5 year antifreeze.

NO, but I have noticed that some of the additives settle to the bottom if it sits for extended periods. When I use a bottle of old oil, I pour half into the engine and then shake it up to make sure everything comes out.

It doesn't expire, but it does lose its effectiveness and need changed about every 50K.
who gave me a thumbs down? It doesn't "expire" if it's just sitting around in a jug.


does unused coolant, in a bottle that has been opened, go bad?

It should be fine. In the engine its got all those metals and moisture to deal with, but not in a sealed bottle.

Google consensus is that unused antifreeze doesn't go bad as long as stored in a clean, sealed container.

I wanted to follow-up on this thread. I decided to not use the old, opened coolant, afterall. Two reasons:

1. I had questions. The fact that I was questioning it, meant that I was worried about it. Decided it wasn't worth the stress.
2. I found the following link on Prestone's website: Prestone Antifreeze/Coolant - Choose your region | Prestone®

It appears that opened coolant that is mixed with water has a shorter shelf life. Granted, I'm using Honda's coolant, and not Prestone. But, given that Honda's coolant is already 50/50 mixed, I decided to go with what Prestone says and assume that I should get a new bottle.


:What is the shelf life of Prestone® Antifreeze/Coolant?A:
If the product is still in the original sealed container or has not been diluted with water then it has a shelf life of many years.


The coolant should not expire any time soon. If it is not in an automobile being used, it is not degrading. With the cap on it, there is nothing contaminating it. From what I was just reading, there is no practical expiration if kept in the original container.

I was seeing sources which said they used coolant over a decade old without issue. When you consider they can recycle this stuff over and over again (assume by cleaning), it will last for a very long time if left alone.

I would have thought in a sealed plastic bottle it would last for ever, certainly a lot longer than 2 years.

Provided the bottle has remained tightly shut and the bottle is nearly full and the a/f is not diluted then the shelf life is way way in excess of five years. I once asked this question of my engine colleagues at Land Rover and they said "10 years probably, if not more"

Neat antifreeze will last forever, even if the container has been opened and partially used...presumably you replaced the cap :p It will be fine to use when ever you want.

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