Why does my coolant look blue?

If you've ever looked at your dashboard in confusion, you're not alone. Many different symbols and lights can pop up, and it can be a lot to take in. One notably confusing symbol is the coolant temperature light, and its function is to show the temperature of your engine. When it's blue, it means your motor isn't quite at the operational driving temperature yet. In other words, the engine needs to heat up. For this particular reason, it's advised that you wait until this blue light turns off before you drive anywhere.

This engine coolant light can turn another: Red. And as you may guess, it means your engine is way too hot! If this light comes on, it's recommended that you turn your car off. This light typically only appears on very hot days, but it can also illuminate if you've been driving a lot of lugging heavy equipment at high speeds. It's not a big concern as long as it turns off after a little while.

Potential Issues

As mentioned before, if the coolant temperature light remains on your dash for a while, you might be a little worried. While the light staying on could be related to a simple electrical issue, you should always take the light seriously if it remains on your dash for an extended period of time. If the blue light persists and everything seems operational, then you should not be too concerned. However, if the red light stays on, it could mean that your engine is at risk of overheating or major damage. We recommend taking your vehicle to a reputable auto repair shop, like Rocky Mountain Car Care, as soon as possible. High engine temperatures could relate to a multitude of engine combustion issues. It's always better to be sure, even if it was a false warning.

 

If your engine coolant light has been giving you a headache, please feel free to take your vehicle to Rocky Mountain Car Care! We'd be glad to answer any of the questions and address your concerns.

Coolant is one of the most critical automotive fluids. It plays an important role in making sure that your car’s engine cooling system is working well. The coolant reduces wear and tear, corrosion thereby checking the damage to the engine block. The automotive coolants come in a range of colours. We can find them in say, purple, blue, green, yellow or orange in the market.

Read: 10 Most Googled Questions On Car Coolant

All coolants might not be compatible with all cars. The anti-freeze mixture you use would vary with the car you drive. It would also depend on when and where your car was made. While picking the right coolant, check with the manual and try to get the one the automaker recommends for your model. If in doubt you can always make use of a service centre.

Here are the 3 different kinds of engine coolant-

  1. Inorganic Additive Technology (IAT)

    Why does my coolant look blue?
    Why does my coolant look blue?
    Green Coolant

    This coolant comes in a green colour. But nowadays, it won’t be a surprise if you encounter a blue IAT. Inorganic Additive Technology coolant demands more frequent changing compared to modern coolants. You might need a coolant change every two years or so. Along with ethylene glycol, they also use silicates in the manufacturing process of IAT coolant. The silicates deter corrosion.

    If there is any such thing as an across-the-board coolant, it would be this one. This is because we can use this coolant on just about any vehicle. Besides, it is relatively more affordable as well!

    Why does my coolant look blue?
    Why does my coolant look blue?

    Why not buy Green Coolant from GoMechanic at ₹119 only? We’ll make sure you get the best at the best price as well! 

  2. Organic Acid Technology (OAT)

    While IAT coolants are made with ethylene glycol, OAT coolants on the other hand use propylene glycol. And another point of distinction between the two is that while IAT is mostly used in earlier models, OAT is suited for the current ones. OAT coolants only need to be flushed in around every 5 years. Because of this, they are Extended Life Coolants (ELC).

    OAT coolants are usually orange. But in rare cases, we might come across a deep green OAT coolant (Honda manufactures dark green OAT coolant). OAT coolants might even come in red, pink, yellow or purple colours.

    As the name suggests Organic Acid Technology coolants are made using organic acids. It is devoid of any phosphates and silicates. GM’s DexCool is an OAT coolant.

  3. Hybrid Organic Acid Technology (HOAT)

    In the olden days, HOAT used to be the yellow coolant. But now things have changed and we can find HOAT in a spectrum of colour from blue to orange. Phosphate-free HOAT can come in turquoise. The anti-corrosive properties of HOAT can be credited to silicates and organic acids present in them. Thus, we can say that HOAT is a mix of OAT and IAT formulation.

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    With Hybrid Organic Acid Technology coolants, you can go an extended period of time without a complete coolant change. Just like OAT coolants, you can use HOAT for 5 years or more. However, if you are looking to buy HOAT coolant make it a point to read the label. Don’t glance at the colour and decide that it is the one for you.

    We can further classify HOAT as follows-

  • Phosphated HOAT (P-HOAT)

    Why does my coolant look blue?
    Why does my coolant look blue?
    (1)

    This coolant comes in pink or blue colour. Phosphated HOAT uses phosphates along with organic acids to prevent corrosion. This coolant is compatible with the models from carmakers like Hyundai, KIA and Honda.

  • Silicated HOAT (Si-OAT)

    If you see a purple coolant somewhere, you know you are probably looking at silicated HOAT. Along with organic acids, this coolant uses silicate instead of phosphate to protect the car engine from corrosion. This coolant is compatible with cars from premium auto manufacturers like Mercedes, Porsche and Audi.

Bear these in mind

Why does my coolant look blue?
Why does my coolant look blue?

  • Just because two cars are from the same brand it doesn’t mean they both use the same coolant.
  • It is generally advised not to mix two coolants together. However, you can go ahead if the brand you use says it’s okay to do so with their product.
  • All yellow coolants are not HOAT. Neither are all orange coolants OAT. The take away is this; don’t judge a coolant by its hue. Read the label.
  • Coolants from some manufacturers need to be diluted. But not others. So, we’ll reiterate; read the label.
  • Periodic vehicle maintenance, servicing and coolant change can do wonders to your car

You should choose the coolant that is compatible with your car. Remember that hybrid cars and EVs do not have a conventional cooling system. Therefore, only use the coolants that are recommended by the carmaker – particularly- in these vehicles.

Why does my coolant look blue?
Why does my coolant look blue?
Coolants

Gone are the days you can tell the composition of the coolant by its colour. You should not let colour be the only basis for choosing the anti-freeze mixture you want to use. Check out the description on side of the container the coolant comes from. We have said it a million times and we’ll say it again; read the label!

You can purchase Golden Cruiser’s Coolant Red. We’ll deliver them to your doorsteps no matter where you live in the country! Download the GoMechanic Spares App for more. 

Why does my coolant look blue?
Why does my coolant look blue?

Read: Engine Oil Grades Explained | Know Your Car Engine Oil

12 COMMENTS

  1. 7 Essential Car Services – GoMechanic Blog May 19, 2021 At 8:50 PM

    […] Read: Which Is The Right Coolant For Your Car? | Coolant Colours Explained […]

    Reply

  2. Suresh chandra jaiswal September 16, 2022 At 5:00 PM

    Which coolant will be best ( green ,blue or red ) and what ratio of water will be added in coolant I’m my HONDA AMAZE. Which manufacturers brand can be used

    Reply

    • Karan Rawat October 1, 2022 At 5:14 PM

      Hi Suresh

      Please check the colour of the coolant which is being utilised by your vehicle and use the similar one. You can go ahead and buy from the below-given link.

      https://gomechanic.in/spares/L4GWQ1707J-smart-cool-1l-green?svariant=L4GWQ1707J

      Reply

  3. Sharon September 26, 2022 At 2:42 PM

    Regarding OAT, you did mentioned it’s Silicates free but you didn’t mentioned the influence of Silicates on seals and o-rings, it might shorten the rubber elements life and this is why some manufacturers (KTM for example) requires Silicates free coolant

    Reply

    • Karan Rawat October 1, 2022 At 5:05 PM

      Hi Sharon

      You are definitely right about the influence of Silicates on O-Rings and rubber seals. Thanks for your suggestion; I have added this to the article.

      Reply

  4. MILIND SHELKE September 27, 2022 At 9:21 AM

    Required A Ready to Use Green Colour Coolant for Maruti Suzuki BS III Swift Vxi – 2009 (Petrol – Engine) – 1 Litre / 3 Litre.
    If Available, Please Forward the Link to Buy & Deliver Online Under Free Delivery / No Shipping charges. Pin Code – 410210. Kharghar – Navi Mumbai – Maharashtra.

    Reply

    • Akshat Ajeya September 29, 2022 At 4:45 PM

      Hey Milind,

      Please share your complete requirement on [email protected] and our experts will help you out.

      Reply

    • Karan Rawat October 1, 2022 At 5:12 PM

      Hi Milind,

      You can go ahead and buy the coolant from the below-given link.

      https://gomechanic.in/spares/L4GWQ1707J-smart-cool-1l-green?svariant=L4GWQ1707J

      Reply

  5. Rakesh November 27, 2022 At 1:19 PM

    Hi, Karan, I have a question,
    I came to know that, my VW Vento 1.6 TDI, 2012 was filled with OAT green colour coolant (the first owner of my car did that), now can I change (after coolant flush) it to Si-OAT type G12/13-grade coolant which is suggested by Volkswagen? and the problem is VW original G12/G13 coolant come with purple colour.

    Reply

    • Karan Rawat December 5, 2022 At 7:10 PM

      Hi Rakesh,

      The only thing to remember is that one should not mix two different coloured coolants. You can go ahead with your plans; there would be no issue using the recommended grade, no matter the colour.

      Reply

  6. Vishal kaushal November 28, 2022 At 1:03 AM

    Hi i have 2009 model pajero sfx. Which coolant i should go for, pls note i stay in mumbai but go to himacgal from months of feb to april, pls advise with how much quantity required.

    Is coolant supposed to be blue?

    Most people think of antifreeze or coolant as green. For years many antifreeze/coolants were green in color but now many coolants come in a variety of colors. Antifreeze or coolant can be yellow, pink or red, blue, and green. The color of the antifreeze/coolant is really based on the formula.

    What coolant is blue in color?

    Phosphated HOAT (P-HOAT) This coolant comes in pink or blue colour. Phosphated HOAT uses phosphates along with organic acids to prevent corrosion. This coolant is compatible with the models from carmakers like Hyundai, KIA and Honda.

    Why did my green coolant turn blue?

    Coolant turns green-blue If a lot of copper and copper alloys are machined, the emulsion/solution can turn green-blue. This has no negative effect on machining.

    Is blue coolant better than green?

    Both coolants will work equally as well in your Nissan, so in terms of a performance benefit there really isn't a difference. We personally would probably use Nissan Green as it comes in concentrated form (makes it a bit cheaper) and feel that changing the coolant more regularly is better for preventative maintenance.