An antifreeze reservoir under the hood of a car with low engine coolant.

3 Reasons Low Engine Coolant Always Needs Your Attention

Low engine coolant might not seem like a critical condition under the hood of your car, especially if your reservoir tank is showing just a bit under what’s recommended by the manufacturer. Ignore it for too long, however, and you could end up creating serious problems inside your engine.

Your antifreeze reservoir needs to stay consistently at the proper level, and if it doesn’t, it can indicate an issue with your vehicle that needs to be addressed, in addition to causing trouble of its own. Here’s a look at three reasons why you should always ensure that your coolant is at the right level.

1. Engine Block = Ice Block

One of the most catastrophic consequences of low engine coolant is an engine that freezes internally during the cold winter months. For this to happen, you’d have to have the mixture of coolant and water dilute to the point where it’s no longer able to resist freezing. It is all too easy to top off a low coolant situation with straight tap water and forget to add coolant later. Do this enough times and your coolant to water ratio will be well away from the recommended 50/50.

Here’s a tip: If you ever notice that your heater is blowing cool air, that’s a possible sign that you have a low-coolant situation. Your heating system relies on warm antifreeze from the engine passing through the heater core, and if there’s not enough to go around, your vehicle’s cabin will stay as chilly as the outdoors.

2. Meltdown

Coolant reservoir

That header might sound more dramatic than what actually occurs, but low engine coolant can just as easily lead to your engine overheating as freezing. Without enough antifreeze, your vehicle’s cooling system will struggle to maintain the correct operating temperature, spiking above it in hot spots throughout its various channels and potentially causing serious damage.

Low coolant and the temperature swings that go with it can also, over time, cause your head gasket to leak. The warping of the gasket will allow coolant to leak through into the combustion chamber, siphoning off even more antifreeze, reducing power and requiring substantial repair efforts.

3. Corrosion

In addition to keeping things just right temperature-wise (not too warm and not too cool), antifreeze is also necessary for preventing corrosion inside your engine. It’s packed with additives that are designed to protect the metal in your block from rust as well as remove any existing corrosion. As a result, if you’re dealing with low engine coolant, then there are likely exposed and unprotected passages inside your engine that are now vulnerable to damage.

Stay on top of coolant levels and you can avoid each of these potential problems with your vehicle. If you notice that your antifreeze is dropping at a consistent rate, then it’s time to check in with your local NAPA AutoCare about a potential leak.

Check out all the chemical & lubricant products available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on low engine coolant, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Image courtesy of Flickr.

about author

Benjamin Hunting

Having been bitten by the car bug at a young age, I spent my formative years surrounded by Studebakers at car shows across Quebec and the northeastern United States. Over ten years of racing, restoring, and obsessing over automobiles lead me to balance science writing and automotive journalism full time.  I currently contribute as an editor to several online and print automotive publications, and I also write and consult for the pharmaceutical and medical device industry.

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