Engine coolant is a mix of water and antifreeze. This mixture is used by the engine cooling system to disperse heat. In the Summer, engine coolant prevents your car from overheating while in the Winter the coolant prevents your engine from freezing. Every car requires engine coolant regardless of the climate where you live or how long and far you typically drive. Running with low engine coolant can cause engine performance problems and of course no coolant at all will eventually destroy your engine. You cannot just pour water or straight antifreeze into your coolant reservoir either. This is because using antifreeze only can cause overheating in warmer temperatures while too much water can result in your radiator or engine freezing and cracking during the colder months. Check your owner's manual for the proper ratio recommended by your car maker. It may be 50-50 or if you live in a very cold environment 70-30 may be required. If you fail to use the proper ratio, any repairs needed for the resulting damage will definitely not be covered under your warranty.
The Engine Coolant Temperature Sensor
The engine coolant temperature sensor sits in your coolant and acts as thermometer.This sensor provides crucial data for both the temperature gauge that lives on your dashboard and the engine control computer. The engine control unit controls and regulates, among other things, the mixture of air and fuel passing through your engine. Engine temperature plays a significant role in determining this mixture. If your coolant is not clean, the engine coolant temperature sensor readings may be off. If you are driving with low engine coolant, the engine coolant temperature sensor may actually be measuring air rather than coolant temperature and returning inaccurate data to the ECU. It is important to keep your coolant clean and topped off so the engine coolant temperature sensor data is accurate and does not negatively impact engine performance. If your engine coolant warning light is lit, it does not mean that you have run out of coolant, but you definitely want to check it and add more if needed as soon as possible.
Checking and Adding Engine Coolant Can Prevent Overheating
Mixing Antifreeze and Water to Make Engine Coolant
When adding engine coolant, be sure to use the mixture and antifreeze type recommended by your car manufacturer. You can buy antifreeze by the gallon, or for the sake of convenience, you can buy engine coolant that is already mixed. Always use room temperature water when you are mixing coolant yourself. To make a 50-50, mixture fill an empty gallon water jug halfway with water then add the antifreeze to fill the container. Use a clean funnel to avoid spilling. Wipe up any spills immediately as the sweet smelling but highly poisonous coolant can be alluring to curious children and pets.
Adding Engine Coolant
Park on a flat surface. I suggest adding coolant when the engine is completely cool if possible. Pop the hood and find the coolant reservoir. An engine coolant reservoir looks a bit like a plastic milk jug with a similar cap. It is positioned close to the radiator and connected to the radiator with a small overflow hose. The coolant within the reservoir will usually be visible and brightly colored. You may have to wipe away some dust or engine grime in order to clearly see the green, yellow, blue, orange, or red engine coolant and the fill line on the side of the reservoir. Some reservoirs have just Add and Full lines. Others have a Hot Full and Cold Full level so which you use depends on whether your engine is cold or hot while you are adding engine coolant. Your reservoir may become stained, making it difficult to distinguish the level of coolant inside the reservoir. If this is the case, you can gently shake the reservoir since the stains will not move, but the coolant will. You can also peer into the container and judge by eye.
Slowly turn the cap counterclockwise. If you hear a hiss as you turn the cap, you should stop and wait a few minutes as there is still built up pressure inside the reservoir. Continue once the hissing stops. Once the reservoir cap is off and stored somewhere it won't get in the way or roll off, place a clean funnel into the reservoir. Pour in the coolant until in reaches the Full or Cold Full mark. If you have added coolant because your coolant warning light was on, start the engine and let it warm up. Make sure the light goes off. If the light is still on, have a mechanic take a look. It could be a problem with the engine coolant temperature sensor or the engine itself.
Checking for an Engine Coolant Leak
While you are checking to make sure you do not have a low engine coolant level, you should also inspect your radiator hoses. If you notice a sweet smelling brightly colored puddle underneath your car, it is most likely due to an engine coolant leak. Coolant leaks are often caused by issues with a radiator hose, the coolant reservoir, or the radiator itself. Radiator hoses are thick, black hoses that should be firmly attached to the radiator so make sure they are. Also visually inspect them for holes or cracks. They should feel firm, not dried out, worn, or soft. Be very mindful of the belt and fan while you check the hoses or disconnect the negative terminal of your car battery beforehand.
The Engine Coolant Flush
Coolant breaks down and gets dirty over time. You should have your coolant drained and flushed according to the guidelines in your car owner's manual. Draining the engine coolant or performing an engine coolant flush are jobs best left to professional mechanics. A mechanic will use highly pressurized water and chemical cleaning agents to thoroughly clean out your system. Coolant is also highly toxic and a professional can make sure it is disposed of properly. Most car makers recommend draining and flushing at between 30,000 and 60,000 miles.
Engine Coolant
If your engine coolant warning light comes on or if you start to notice your engine temperature gauge heading into the red area, these are clear signs that your engine is running hot and will fail. You will need to stop as soon as possible, turn off the car completely, and wait for the engine to cool down. Do not pop the hood if steam is coming out and never remove the radiator cap when the engine is hot or overheated. You can be severely scalded. Check your coolant level when your engine has cooled down and add additional engine coolant if necessary.
