#Engine coolant manual#

While the latter should be more accurate, the former will likely do. Thankfully, simple ones, which usually look like a large eyedropper with little colored balls inside, aren’t very expensive others might have a larger tank with a pointer inside and a big bulb on top. To check your coolant’s freezing point, you’ll need some sort of tester. If you check the level of coolant in the radiator, it should be right to the bottom of the filler neck. If you suddenly release that pressure, the coolant can instantly boil and spray very hot coolant out like a geyser. For that, the radiator needs to be cooled down, at least to the point you can leave your hand on it, because the cap you remove to check it holds a certain amount of pressure in the radiator, in part to help raise the boiling point of the coolant. The translucent overflow tank can usually be checked visually regardless of engine temperature, as there should be different levels marked on it for “Cold” and “Hot.”Įven if the coolant tank is at the right level - and especially if it’s low - you may want to check the coolant level in the radiator, as well. If it’s not obvious, you can find the overflow tank by following the small-diameter hose that is attached to the radiator’s filler neck, just below the filler cap. There are two places under your hood to check coolant level: the overflow tank (which some old cars may not have) and the radiator itself. Otherwise, since you don’t know how much you’ll need to add, you could end up with the wrong ratio of antifreeze and water. Few systems hold more than two gallons altogether, so a gallon of distilled water - which you can get at almost any store that sells bottled water - should suffice.Īlthough you shouldn’t have to add coolant to your system unless there’s a leak, it’s usually easiest to add a store-bought 50/50 “premix” if you do. It is recommended to use distilled water in your radiator, not tap water, as it contains minerals that can harm your car’s cooling system. You could also check the color when you check your vehicle’s coolant level, but it may have turned murky if it’s old, and it’s possible someone along the line added the wrong type.Įven what water you use is a concern.

#Engine coolant manual#

If your owner’s manual doesn’t spell it out, your local auto parts store should be able to help you. It used to always be green, but orange is now fairly common, and there are also other colors. Choosing the Right AntifreezeĪntifreeze comes in different colors, and you need to get the right one for your car. While the best freeze protection comes with about 70% antifreeze - down below minus 50 degrees - you shouldn’t use anything stronger than 50/50 if you can get by with it due to the aforementioned problem with heat transfer, which can make your engine overheat. By contrast, straight antifreeze will freeze at about 0 to minus 20 degrees. Furthermore, antifreeze doesn’t absorb heat from your engine as well as water does.Īlthough the specifics vary somewhat, the widely recommended solution of a 50/50 mix of antifreeze and water will freeze at about minus 35 degrees Fahrenheit. Why should you always mix antifreeze and water? Because - against all logic - straight antifreeze will freeze at a higher temperature than the usual 50/50 mix of antifreeze and water. Related: Why Is My Car Leaking Coolant? Useful Coolant Terminology and FactsĪntifreeze is mostly straight ethylene glycol or propylene glycol, which is very poisonous, while coolant is the result of mixing antifreeze with water, which you should always do. If you want to skip right to checking whether you have enough, you can scroll down to “Checking Your Coolant Level.” If you want to skip to testing your level of protection, you can scroll down to “Checking the Freezing Point.” There are two checks you can easily do on your coolant, or the mixture of antifreeze and water: whether you have enough of it and if it’s still protecting your engine in cold temperatures. If a vehicle’s cooling system only used water, the engine would freeze in cold temperatures, leading to cracking and failure. It also adds antifreeze protection and acts as a lubricant for some of the engine’s components. As engines get very hot, coolant helps distribute heat to help prevent overheating and engine damage.