How to change your Wira coolant

Posted: 1st June 2010 by Jacky Yong in Cars
Tags: , , , ,

Since my wife’s Wira has been changed to using NGV, the engine runs a bit hotter. There are a lot of discussion about making the engine run cooler, ranging from upgrading to a bigger radiator, using TAP device and installing gear cooler. But nothing beats the basic of giving proper attention to your engine coolant. Therefore I have decided to change the engine coolant myself, so I can be in more control of what goes into the radiator compartment.

Why am I being so choosy? Simply because just putting pipe water inside your radiator will just not be enough. There are also additives that you need to add, not just to make your engine run cooler, but also to protect the innards from rusts and other metal particles.

I am going to document down the process that I took to change the coolant. Please remember that not all cars are as easy to DIY as the Wira. And even among Wiras there are a few models, so not all models are built the same. So when you really want to take the plunge, please practise common sense. I shall not be held responsible for any blunder or bodily injury that you sustain trying this out.

My Wira is the 4G15 engine, manufacturing year is 1998. The radiator is actually made up of two fans spread over one huge radiator block. The two red squares below marks the rough location of the two fans.

Wira radiator

The red boxes are the rough locations of the two fans. The arrow marks the location of the plug underneath the radiator.

You will need to prepare the materials for your project. The rough volume of the coolant is 4 litres. I bought original Toyota coolant from Toyota Service Centre in Balakong. The Toyota coolant recommends the ratio of 50/50 of coolant and water, so for this project you will need 2 bottles of coolant and 2 bottles of battery water.

Toyota LLC and battery water

Two litres of Toyota Long Life Coolant and two litres of battery water

Why battery water? As I said, I want to be in control of what goes into the radiator. Normal pipe water contains a lot of dissolved minerals, and if mixed inside the radiator might induce the formation of rust or other salt which may clog up the radiator.

Edit : A reader mentioned that it might be a better idea to use RO water instead. I did some checking and true enough, some manufacturers do mix minute quantities of SO4 (acid). (Thanks Jennifer!)

Size 12 mm screw and wrench

Size 12 mm screw and wrench

You’re gonna need these wrench set too to dismantle the various screws. And also before you start, I let the car cool itself overnight. Easier to work with coolant that is err ….. cool.

Now comes the toughest part; jacking up the car! I don’t need to show you how it’s done, but just jack it high enough to enable easier access to the radiator plug.

Once you crawl under the car (did I tell you that you WILL get yourself dirty trying this?) locate the plug. It should be just a plastic plug that you can loosen. The plug does not bear any load, so it should loosen pretty easily with just your hand.

The radiator plug

Note the plug. Upon loosening the coolant will drip through another vertical hole, just like a pipette that you used to play in your chemistry class

Open the radiator cap above to assist in the the draining of the coolant. You may want to measure the amount of fluid coming out. This will give you a rough idea of how much coolant that you need to fill back later. But I have done this exercise twice to be certain that the 4G15’s radiator coolant volume is 4 litres.

A good idea is to properly clean the innards of your cooling system while changing coolant. This should be easy, just fill up the radiator with normal pipe water and start the engine. Someone did suggest to let the engine run until the radiator fan turns on. Because only then will the liquid start circulating, removing any debris inside. You may also want to use one of those off-the-shelve radiator cleaner for better cleansing.

You can’t have a clean coolant without cleaning the reservoir as well. Cleaning it is easy, just dismantle the reservoir and clean the internals with soap and brush. You’ll be surprised at how much oxidized iron gets build up here.

Remove the screws here

Remove the screws here to get to the reservoir

After your have thoroughly cleaned the radiator, it’s time to put the pieces back. Tighten back the plug. Pour one bottle of Toyota LLC and one bottle of battery water first through the main radiator cap. Careful, you may spill the mixture out if you pour them too fast. There is a lot of air bubbles still trapped inside there.

Go ahead, start the car! * GULP * yes, despite popular belief, it’s actually okay to start the car with the radiator cap still unlatched, PROVIDED the car is still cold. You will immediately see air bubbles appearing. Go ahead, now you can pour the rest of the mixture in.

Optional : You might want to mix the final 1 litre of battery water and 1 litre of coolant together in a separate container before you pour the rest of them in. This is to guarantee a proper coolant : water ratio. But me being myself, I just simply pour by feel. Too lazy to measure.

You may not be able to finish the entire mixture, but that’s perfectly okay. No need to waste the mixture, you still need to top up the reservoir remember? Just pour the remaining mixture into the reservoir.

There you are done! To make sure everything is running smoothly, take the car for a spin. If you do not notice any more leaks, then congratulations, you have successfully changed the coolant yourself!

  1. Zaki says:

    Thank you for sharing the knowledge Jacky. i might try this myself this weekend.

  2. locoguy says:

    After you performed all this, may I know the position of the temp indicator on the meter? 2.5 or 3 out of 6 block? my indicator there is at the middle, i.e. 3 out of 6. I was thinking to use those Pre-mixed coolants so more accurate ratio n easier to refill in the future. any comments? Appreciated ur sharing here 🙂

  3. Jacky Yong says:

    Before I changed the coolant, it was at the second line from the bottom. After I changed the coolant, it is still at the second line from the bottom, no change. Premixed coolants are good, no need to mix the coolant content yourself. It also saves you the hassle of finding distilled water to mix. Battery waters might not be clean enough. But you will also notice that most coolants comes with anti-freeze, which is stupid and unnecessary in our climate!

  4. jennifer says:

    how much u paid for 1L of toyota long life coolant? I m using aluminum radiator atm u think tis LLC suitable? i asked 3 radiator shops opinion the other day, they all told the same thing i.e. Not to use battery water for radiator as it contains other ingredient like maganese. They said should only use Distilled water or Reverse Osmosis water that r sold in supermarket around RM3 to RM5 per big bottle of 5.5L. 1 shop also said Toyota LLC is not recommended due to massive Fake one in the market. They said we can’t differentiate from the bottle coz those fake one r using genuine recycle bottles with genuine engraved of manufacturing date n plastic code on the bottom of each bottle. They told me as a general rule, those at RM10-20 per bottle sold at spart part shop are mostly fake. Just to share here what i heard from them 🙂

  5. Jacky Yong says:

    Hi Jennifer,

    The Toyota LLC cost me RM25.90. As I mentioned, I went to Toyota’s Service Centre in Balakong to buy my parts. I never trust the spare parts shop outside. I did purchase from the spare parts shop once and true enough, they were fake!

    Interesting discussion about the type of water to use. Battery water are supposed to be pure distilled water, but it seems some manufacturers do put in minute quantities of SO4 (acid). Perhaps it is a good idea to use RO water instead.

    For aluminium radiators, they should not use coolants that contains silicate or borate. As far as I know, Toyota LLC does not contain them, but let me update this again once I have more info.

  6. jennifer says:

    Regarding the claim that coolant that contains silicate inappropriate for aluminum radiators, hmm, there’s one article in current month Hypertune Magazine about Cooling System, a very nice writeup in it, I remembered there’s a line that state “silicate addictive” type of coolant is “specially made” for aluminium radiator. Have a read at MPH or Border’s bookstore hehe.

    also something about silicate here, with lab testing etc..

  7. mihonkenji says:

    Dear Jennifer & Jacky Yong,

    Quotes (from

    Here’s the simplified story. Silicates (usually found in the green stuff) are very protective for aluminium., as long as they last. It was feared they didn’t last too long, but I understand there is recent research that says they last longer than previously thought. But they are not “long life”.

    HOWEVER, the Japanese manufacturers hate silicates, feeling they are too abrasive and chew up water pump seals-even hard ceramic seals. They like phosphates, which are good for alum. but not as good as silicates.

    HOWEVER, the Europeans hate phosphates, because they know that many/most people use plain tap water instead of distilled. OK, no big problem in most of Japan and the US because we have relatively “soft” water, but most of Europe has ~equal parts of water, calcium and magnesium pouring out of the taps–read HARD water. Seems that phosphates cause the Ca and Mg to turn to tiny rocks–not too good.


    So, u might want to consider something good for aluminium radiator that is Silicate-free and Phosphates-free.

    The Caltex Extended Life Coolant is one such example.

    Detail :

    But, it’s not so straightforward. I shall reply more on this later. Have a nice day.

  8. Jacky Yong says:

    Just an update, this is how I know that my coolant are original: