Changing Coolant.

[bradp51]

I have two Aurions. I changed the coolant in one about 6 months ago using the method as seen on the youtube by the Car Care Nut.  I just did it again on the second Aurion.  This time instead of just emptying the radiator on the bottom tap I also attached tubes to the metal pipes on the engine block plugs.  You have to jack the car up to get to these.  The front one is behind the dipstick tube and the rear one is easy to see and get to.  The front one I moved the heatshield for the manifold, but did not take the 02 sensor out.  The front one is difficult to get to. The surprising thing to me was that I got nearly 5 litres of coolant out of the rear block tap.  I carefully measured it all into buckets and got more than 7 litres out of the system.  This included about 300ml out of the overfill plastic tank.

The car care guy goes thru a great video of purging the system which works great.  I read in my Haynes manual for the car about the two engine block taps.  Haynes also suggests removing the thermostat and flushing water thru with a garden hose via the radiator hose.  I did not do that but I did put 2 x bottles or radiator flush in and drove for half an hour then came back let it cool and then jacked it up and emptied all that fluid.  I then filled it up with brand new toyota genuine fluid from the dealer which was cheap.  Then went thru the air bleeding which works exactly like he says it does.  I purchased the container with the special radiator caps from amazon as he links to his video. Works well.  I changed the oil at the same time and filter.  I do oil changes now at 7500 km and use Mobil 1 full synthetic.  I managed to buy some in bulk recently on special and use it in the other Aurion and another car which takes the same oil grade.

Just thought I would  share my experience about using the engine block taps.  You use a 10mm spanner to undo them and there is about a 25mm long 8mm spigot or pipe that you attach a hose to which i fed into a container under the car.  It is a bit time consuming but I think worth it if you want to fully change the fluid out of the  whole system not just a portion of it.

[Tony Prodigy]

That was kind of you to post up Brad. Thanks for the tips.

I am planning to do mine pretty soon and as always, like to take photos and post up a nice little DIY for others to see for themselves and hopefully take something from it.

You did good to get that much coolant from the block. It's important to get as much of the old stuff out as possible and even try to flush more out where possible.

The system takes around 9lt if I'm correct, so you got pretty close. I would always recommend to drain the block and try to flush more out. For the flushing process, I've purchased a stash of demineralized water for the flushing as opposed to using the garden hose. I wouldn't flush with tap water. It's too contaminated in my opinion, not to mention the minerals you end up introducing into the engine. 

I've been meaning to get under it and investigate those drain bungs before I attempt the work. This is my pre planning stage so I can be ready to go on any given day.
Have all the necessary tools, apparatus, fluids and prior knowledge ready so there's no issues.

 

[ZZT86]

How timely, I did this exact same procedure the other day when it was hot here in Melbourne, which made bleeding quicker.

I too also accessed the block taps but couldn't see the front one & just ignored it as I got most from the rad tap (4.75L) & then the balance (2.5L) from the rear block tap. I connected a hose to both before opening the tap for extra cleanliness.

Not flushing using tap water makes sense (on a newish car at least) as the water isn't pure like the premixed stuff in the Toyota SLLC bottle of which I purchased 2 (10L) for about $70 from my local dealer.

If tap water is used then some is likely to remain in the system & eventually degrade the overall quality of the coolant & potentially cause premature seal & bearing failure, something we're all trying to avoid in a cramped 3.5L V6 FWD setup. Some would call it overkill, I'm just taking extra precautions.

Some additional notes I made:

1: open bleeder 1 - 1.25 turns max otherwise air may get in

2: bleeder hose not immersed into overflow coolant funnel otherwise will suck back in

3: install cable tie to base of bleeder hose to prevent leak & falling off

4: make sure funnel rad-cap tight fit otherwise will leak (had to tighten mine)

5: bleed process took 13minutes in 30+degree heat in garage before steady flow from bleeder hose

6: let engine idle a further 15minutes for coolant flow to normalise & little to no air/bubbles from overflow funnel

7: next time use both block taps to drain

8: fill coolant to crease on funnel plenty otherwise risk overflow during bleeding process & engine running @ 2500rpm

After turning engine off I extracted excess coolant from funnel, removed the funnel & bleeder cap from radiator neck, filled to top then closed her off with factory cap. Filled cars overflow bottle to full & let the engine cool overnight. In morning when cold refilled overflow bottle to full as engine cool down process will suck some back in, lightly washed engine bay of coolant & dirt & dried it before starting. I checked the coolant level was full after a few drive cycles to make sure it was all perfect, car runs beaut 🙂

A painless process all made possible due to the great AMD aka the Car Care Nut, our greatful & dedicated friend from the Toyota world 🙂

 

Edited February 3, 2023 by ZZT86
credit to AMD

[Tony Prodigy]

Nice one Rick. All this talk about changing coolant is getting me psyched up to do mine 😄

On 2/3/2023 at 9:04 PM, ZZT86 said:

I too also accessed the block taps but couldn't see the front one & just ignored it as I got most from the rad tap (4.75L) & then the balance (2.5L) from the rear block tap. I connected a hose to both before opening the tap for extra cleanliness.

I had a quick look online and this is the picture I found for the front drain point. (SEE BELOW).
I haven't physically looked at mine yet, but according to the picture, it appears to be next to the oil cooler flange adjacent to the dip stick tube.

I wonder how much more coolant one can recover if both are drained instead of just the rear which you did. I also wonder if the heater core also drains back whilst utilizing the rear drain. I would assume approximately 500mm or so in the heater core.

The coolant capacity is 9.4lt. You were able to extract 7.5lt leaving 2.15lt, so I would be inclined to drain the front section of the engine too, to get as much out as possible.
Flushing can be another option, but here's what can happen. 

1. Those who foolishly use the garden hose to flush will introduce contamination and will inevitable leave behind a few litres of mineralised water, which will degrade and contaminate the coolant.

2. Flushing with demineralised water is preferable, but will also leave a quantity of water inside which will then dilute the already 50/50 mix thus reducing it's overall effectiveness.

So, in my mind, I would wait and see how much I can collect from radiator, front and rear drain bolts and see if it's even worth flushing.
If one decides to replace the thermostat, then you could pour demineralised water into thermostat hole and allow to drain the block this way and the same for the radiator too. 
The heater core is the only thing that concerns me. I guess you could force the coolant out with compressed air. Just need to access the heater hoses, if that's easy enough.
It would be interesting to see how close to 9.4lt one can get doing all this.

You make some good points too Rick. Namely these:

On 2/3/2023 at 9:04 PM, ZZT86 said:

1: open bleeder 1 - 1.25 turns max otherwise air may get in

2: bleeder hose not immersed into overflow coolant funnel otherwise will suck back in

3: install cable tie to base of bleeder hose to prevent leak & falling off

I'll do a bit more research before doing mine. I had to recently buy two 5lt coolant from Toyota because I have no idea where the other two are. I also have on hand, a full set of Genuine Toyota Parts, cooling system hoses, thermostat, gaskets, water pump (new Improved Toyota Item with petal design flange) and Radiator for any incidental issues that may arise.
I might just do the coolant change this time and decide later at which point to do a full cooling system overhaul. At that point, I'll just swap out all those parts I have stored and see it through another 10 years or so. The car is running great at 150+K and mostly original. The only things I've had to replace on the engine during my ownership thus far was the upstream O2 sensor. That's it apart from routine maintenance. 

 

 

Edited February 4, 2023 by Tony Prodigy

[ToyotaTitties]

Hey guys I put about 250 MLS of green premixed nulons  coolant into tmy Aurion that filled with Toyota red?? Should I be worried ???

 

 

[ZZT86]

Why did you do that given both different colours? Going by what I've read online, see below, if same type of coolant then OK. Even if small quantity of the differing types, as you have poured, also OK. Personally I'd be somewhat concerned & just dump the lot, problem is you will never be able to extract all of it but it's possibly the best solution in the end.

Inorganic Acid Technology (IAT): With a bright green color, IAT was the coolant of older vehicles up to the mid-90s. This type has silicates and corrosion inhibitors known as phosphates. It has a life expectancy of 2 years.

Organic Acid Technology (OAT): Available in orange and red colors, OAT is the coolant of newer models. Instead of having phosphates and silicates, it has neutralized organic acids and azoles as corrosion inhibitors. This type lasts about 5 years.

[Tony Prodigy]

Do you have a picture of the actual Nulon Product you used ? They make several types I believe.

Not to disprove anyone here, but Toyota's pink coolant is a HOAT and not just OAT and even mixing those two can be detrimental.

If the O.P. has only topped up the reservoir, then I'd be dumping it out, flushing it with clean water then top up with the correct coolant assuming it has Toyota Pink SLLC in it already. If in doubt, then the whole cooling system should be dumped and flushed with demineralised water. Drain the block, radiator, everything.

If you're handy, you have post here to guide you on the whole process.

Here's a copy and paste from the interwebs on this

Can I mix OAT coolant with Toyota SLLC pink ?

No, you should not mix different types of coolant, including OAT (Organic Acid Technology) and Toyota's SLLC (Super Long Life Coolant), even if they are the same color, as they may use different technologies that can cause gelling, sludge, and severe engine damage. It is best to completely drain and flush the system before adding a new type of coolant to avoid chemical reactions. 
Why you should not mix coolants
Chemical incompatibility: Mixing different types of antifreeze can cause a chemical reaction that creates a gel-like substance, which can clog your cooling system and lead to overheating.
Different formulations: Different coolants use different technologies (e.g., OAT, HOAT, IAT). Toyota's SLLC is a HOAT coolant, and mixing it with other types, especially traditional OAT or IAT, can be detrimental.
Severe consequences: A mix of incompatible coolants can cause severe damage, including a ruined radiator, broken head gaskets, and a broken water pump.
Reduced longevity: The mixture may not last as long as the manufacturer-recommended coolant, leading to a shorter service life. 
What to do instead
Drain and flush: To switch to a different coolant type, you must completely drain the old coolant and flush the system with distilled water before refilling with the new coolant.
Use only the recommended type: To avoid issues, use only the specific Toyota SLLC, or a HOAT coolant that is certified as a compatible alternative, as recommended by the manufacturer.
Check the manual: Always refer to your vehicle's owner's manual for the correct type and specifications of coolant required. 

[ZZT86]

And there you go folks - I didn't know Toyotas SLLC Pink coolant was HOAT & different to the red stuff. Just goes to prove that you can't be too careful with these things, unless you care not to shorten the life of your precious water pump & the balance of the cooling system. Thanks Tony.

Which reminds me - my 86 could do with a dump/flush/change.

 

[Novicebutnice]

On 10/6/2025 at 10:50 PM, ToyotaTitties said:

Hey guys I put about 250 MLS of green premixed nulons  coolant into tmy Aurion that filled with Toyota red?? Should I be worried ???

 

 

YES BE VERY WORRIED!!!!

[Novicebutnice]

On 10/9/2025 at 4:23 PM, Tony Prodigy said:

Do you have a picture of the actual Nulon Product you used ? They make several types I believe.

Not to disprove anyone here, but Toyota's pink coolant is a HOAT and not just OAT and even mixing those two can be detrimental.

If the O.P. has only topped up the reservoir, then I'd be dumping it out, flushing it with clean water then top up with the correct coolant assuming it has Toyota Pink SLLC in it already. If in doubt, then the whole cooling system should be dumped and flushed with demineralised water. Drain the block, radiator, everything.

If you're handy, you have post here to guide you on the whole process.

Here's a copy and paste from the interwebs on this

Can I mix OAT coolant with Toyota SLLC pink ?

No, you should not mix different types of coolant, including OAT (Organic Acid Technology) and Toyota's SLLC (Super Long Life Coolant), even if they are the same color, as they may use different technologies that can cause gelling, sludge, and severe engine damage. It is best to completely drain and flush the system before adding a new type of coolant to avoid chemical reactions. 
Why you should not mix coolants
Chemical incompatibility: Mixing different types of antifreeze can cause a chemical reaction that creates a gel-like substance, which can clog your cooling system and lead to overheating.
Different formulations: Different coolants use different technologies (e.g., OAT, HOAT, IAT). Toyota's SLLC is a HOAT coolant, and mixing it with other types, especially traditional OAT or IAT, can be detrimental.
Severe consequences: A mix of incompatible coolants can cause severe damage, including a ruined radiator, broken head gaskets, and a broken water pump.
Reduced longevity: The mixture may not last as long as the manufacturer-recommended coolant, leading to a shorter service life. 
What to do instead
Drain and flush: To switch to a different coolant type, you must completely drain the old coolant and flush the system with distilled water before refilling with the new coolant.
Use only the recommended type: To avoid issues, use only the specific Toyota SLLC, or a HOAT coolant that is certified as a compatible alternative, as recommended by the manufacturer.
Check the manual: Always refer to your vehicle's owner's manual for the correct type and specifications of coolant required. 

The problem is that Nulon at time of posting Nulon DOES NOT on their pink coolant mention that it is suitable for Toyota's (on their website).

Whereas on the red bottle it does.

I currently use the Nulon RED in my 2017 Camry RZ

BUT!!!! I did get my mechanic to do a flush (as best as possible)

This was in 2022 and due to my OCD OTT and of course my SKF, JNJ, CFV, UJN, ENF, PNF......... I got it flushed and changed again a couple of months ago.

On the Nulon website for the "red coolant":

Toyota K2601G, TOYOTA SUPER LONG LIFE COOLANT

Pink.... No Toyota spec.......

[Novicebutnice]

On 10/9/2025 at 5:24 PM, ZZT86 said:

And there you go folks - I didn't know Toyotas SLLC Pink coolant was HOAT & different to the red stuff. Just goes to prove that you can't be too careful with these things, unless you care not to shorten the life of your precious water pump & the balance of the cooling system. Thanks Tony.

Which reminds me - my 86 could do with a dump/flush/change.

 

Nulon on their red coolant:

Toyota K2601G, TOYOTA SUPER LONG LIFE COOLANT

Whereas on their "Pink Coolant" it doesn't claim to meet any Toyota spec.........

Which is why I went with "Red" on my 2017 Camry RZ

Edited October 10 by Novicebutnice

[Tony Prodigy]

On 2/3/2023 at 9:04 PM, ZZT86 said:

How timely, I did this exact same procedure the other day when it was hot here in Melbourne, which made bleeding quicker.

I too also accessed the block taps but couldn't see the front one & just ignored it as I got most from the rad tap (4.75L) & then the balance (2.5L) from the rear block tap. I connected a hose to both before opening the tap for extra cleanliness.

Not flushing using tap water makes sense (on a newish car at least) as the water isn't pure like the premixed stuff in the Toyota SLLC bottle of which I purchased 2 (10L) for about $70 from my local dealer.

If tap water is used then some is likely to remain in the system & eventually degrade the overall quality of the coolant & potentially cause premature seal & bearing failure, something we're all trying to avoid in a cramped 3.5L V6 FWD setup. Some would call it overkill, I'm just taking extra precautions.

Some additional notes I made:

1: open bleeder 1 - 1.25 turns max otherwise air may get in

2: bleeder hose not immersed into overflow coolant funnel otherwise will suck back in

3: install cable tie to base of bleeder hose to prevent leak & falling off

4: make sure funnel rad-cap tight fit otherwise will leak (had to tighten mine)

5: bleed process took 13minutes in 30+degree heat in garage before steady flow from bleeder hose

6: let engine idle a further 15minutes for coolant flow to normalise & little to no air/bubbles from overflow funnel

7: next time use both block taps to drain

8: fill coolant to crease on funnel plenty otherwise risk overflow during bleeding process & engine running @ 2500rpm

After turning engine off I extracted excess coolant from funnel, removed the funnel & bleeder cap from radiator neck, filled to top then closed her off with factory cap. Filled cars overflow bottle to full & let the engine cool overnight. In morning when cold refilled overflow bottle to full as engine cool down process will suck some back in, lightly washed engine bay of coolant & dirt & dried it before starting. I checked the coolant level was full after a few drive cycles to make sure it was all perfect, car runs beaut 🙂

A painless process all made possible due to the great AMD aka the Car Care Nut, our greatful & dedicated friend from the Toyota world 🙂

 

Just re-reading some old posts and didn't realise that AMD actually responded to your comment ! Wow, what a rare occurrence. He most certainly wouldn't be doing that nowadays with his gruelling schedule. One of the lucky few.

I also re-read my coolant flush Thread and looks like the moderators have defunct the video parts I uploaded too. I wished they wouldn't do that. Ruins the continuity..

[Tony Prodigy]

12 hours ago, Novicebutnice said:

The problem is that Nulon at time of posting Nulon DOES NOT on their pink coolant mention that it is suitable for Toyota's (on their website).

Whereas on the red bottle it does.

I currently use the Nulon RED in my 2017 Camry RZ

BUT!!!! I did get my mechanic to do a flush (as best as possible)

This was in 2022 and due to my OCD OTT and of course my SKF, JNJ, CFV, UJN, ENF, PNF......... I got it flushed and changed again a couple of months ago.

On the Nulon website for the "red coolant":

Toyota K2601G, TOYOTA SUPER LONG LIFE COOLANT

Pink.... No Toyota spec.......

I think, for what it's worth, it is better peace of mind to just use what the factory used. If your car came out with RED Toyota coolant, then of course you should just use that. Flushing can hep, but it is a long and drawn out process to get into just to save a couple of bucks just to use another product.

For me it was a no brainer. I was very happy to pay a small premium and buy Toyota SLLC and despite this, I only had to drain all the various points then simply refill. No flush required really but I did refill my cooling system with demineralised water to help purge out traces of the spent coolant. Not necessary but like your  OCD, OTT,SKF, JNJ, CFV, UJN, ENF, PNF 😂, I too, suffer from a similar affliction 😄 

[Novicebutnice]

15 hours ago, Tony Prodigy said:

I think, for what it's worth, it is better peace of mind to just use what the factory used. If your car came out with RED Toyota coolant, then of course you should just use that. Flushing can hep, but it is a long and drawn out process to get into just to save a couple of bucks just to use another product.

For me it was a no brainer. I was very happy to pay a small premium and buy Toyota SLLC and despite this, I only had to drain all the various points then simply refill. No flush required really but I did refill my cooling system with demineralised water to help purge out traces of the spent coolant. Not necessary but like your  OCD, OTT,SKF, JNJ, CFV, UJN, ENF, PNF 😂, I too, suffer from a similar affliction 😄 

Hi Tony,

I decided to use non-genuine coolant for a few reasons, though price wasn't one of them 🙂

For me what it came down to was watching a Car care nut video about coolant, and coolant being left in too long becoming abrasive to the water pump (he believes that the service interval is too long).

I noticed on my car that on the overflow bottle, some coolant residue on the outside that was powdery and felt abrasive (I saw it after it dried)..... and this got me a tad concerned about the properties of the genuine coolant... as well as that there would be any residue on the outside of the overflow bottle.

So I decided to use Nulon after doing a bit of research on the non-genuine offerings, unlike Toyota..... Nulon doesn't make water pumps....... (starts slowly putting the aluminium foil on my head)....... and so they have no reason to sell me a product that will over time destroy my water pump.

With the Nulon the overflow residue is completely different as well as less frequently seen, and as a result...... SO FAR... I have zero regrets.

"I too, suffer from a similar affliction "

This is great for our cars... but bad for our wallet..... 😂




 

Edited October 11 by Novicebutnice

[campbeam]

9 hours ago, Novicebutnice said:

Hi Tony,

I decided to use non-genuine coolant for a few reasons, though price wasn't one of them 🙂

For me what it came down to was watching a Car care nut video about coolant, and coolant being left in too long becoming abrasive to the water pump (he believes that the service interval is too long).

I noticed on my car that on the overflow bottle, some coolant residue on the outside that was powdery and felt abrasive (I saw it after it dried)..... and this got me a tad concerned about the properties of the genuine coolant... as well as that there would be any residue on the outside of the overflow bottle.

So I decided to use Nulon after doing a bit of research on the non-genuine offerings, unlike Toyota..... Nulon doesn't make water pumps....... (starts slowly putting the aluminium foil on my head)....... and so they have no reason to sell me a product that will over time destroy my water pump.

With the Nulon the overflow residue is completely different as well as less frequently seen, and as a result...... SO FAR... I have zero regrets.

"I too, suffer from a similar affliction "

This is great for our cars... but bad for our wallet..... 😂




 

Appreciate that you mentioned The Car Nut who recommends changing the coolant every 5 years or 50,000 miles [80,000 kms] mainly because it becomes acidic impacting the water pump and head gasket. 

I have replaced the water pump and previously noticed some coolant loss a few years ago. This has prompted me to use additives in the coolant to protect the head gasket as part of preventative maintenance.

Last purchase ended up being the Repco Brand red coolant concentrate and my online research indicated that it was manufactured by Penrite[?].

No immediate need to purchase more coolant but have changed my mind to take advantage of this weekend's 40% discount of Penrite products at Repco.

 

[Tony Prodigy]

On 10/11/2025 at 10:25 PM, Novicebutnice said:

Hi Tony,

I decided to use non-genuine coolant for a few reasons, though price wasn't one of them 🙂

For me what it came down to was watching a Car care nut video about coolant, and coolant being left in too long becoming abrasive to the water pump (he believes that the service interval is too long).

I noticed on my car that on the overflow bottle, some coolant residue on the outside that was powdery and felt abrasive (I saw it after it dried)..... and this got me a tad concerned about the properties of the genuine coolant... as well as that there would be any residue on the outside of the overflow bottle.

So I decided to use Nulon after doing a bit of research on the non-genuine offerings, unlike Toyota..... Nulon doesn't make water pumps....... (starts slowly putting the aluminium foil on my head)....... and so they have no reason to sell me a product that will over time destroy my water pump.

With the Nulon the overflow residue is completely different as well as less frequently seen, and as a result...... SO FAR... I have zero regrets.

"I too, suffer from a similar affliction "

This is great for our cars... but bad for our wallet..... 😂




 

Hi Stephen,

A few things to consider here. 

I completely understand where you're coming from. Nobody want to harm their precious 2GR-FE engine, least of all me.

The factory fill coolant is specified to be replaced at 90 months or 150KLM from new according to the service schedule. (7 years). It can be done earlier if one chooses. Subsequent coolant flushes will then be substantially more frequent and this is 45 months after the original flush or 3.75 years, which also in line with AMD's advice in the above video. Once the system has been opened from factory, the potential for some contamination is increased and as such the service interval is reduced

 To eliminate any possibility of the coolant turning acidic, you should replace SLLC pink HOAT or OAT coolant at least every four years. Just remember though, HOAT and OAT coolants are not as aggressive as just plain glycol coolants. Those don't last and are recommended to be replaced every two years. 

If you recall, I actually did a PH test strip on my factory coolant when I drained it and it indicated no levels of acidity compared to the fresh coolant, so that was testament enough for me that the Toyota product is superior. Scotty Kilmer even recognizes Toyota's SLLC coolant as being the best coolants in the world and not being sponsored either, his opinion is highly valued by the car community world wide. That's enough peace of mind for me.

You also mentioned Nulon doesn't make water pumps, so the idea being that they have no agenda to sell you one if yours fails due to bad coolant. ?
Not sure if you know this, but Toyota don't make water pumps either. They're actually made by Aisin, which is a Japanese OEM manufacturing company.
The water pumps with the Toyota logo on them are actually Aisin pumps, so Toyota really couldn't be that diabolical to create a coolant which will inadvertently cause harm to your engine parts. I really believe Toyota wanted to create a coolant that is more superior than what was available at the time. They did start out with Toyota Red, and it was top notch, then pink for the newer engines.

That powdery residue you mentioned was also present on my overflow bottle. I could never understand how or why is was there either. I just assumed it was just some coolant that had somehow leaked out of the bottle when at a steep incline perhaps and then it just turned that way from the engine bay heat. I doubt it had anything to do with anything internal going bad. I don't think it's anything to be concerned about. I'd love to get the Car Care Nut's opinion on that actually..

A way to keep tabs on the health of your water pump seal is to check the weep hole from time to time. If it hasn't weeped so far and it's still original, then the coolant is doing its job. My water pump is still original and have no weepage as yet. I have also been under the car to inspect the mating surfaces of the head and block and nothing there either. Those would be the tell tale signs of an acidic system eating the alluminium up from the inside. Thankfully I did my coolant and won't have to worry about it for some time yet.

If you choose to go with non original coolant, then you'd need to really flush the system out properly to rid any traces of SLLC pink. You don't want to be mixing different chemical strains. Once completely flushed then you can just continue using that coolant of choice.
I stuck with original pink, because there was no way I could flush the entire system without being more invasive and considering it was still the factory fill, I felt confident it wouldn't present too much hassle going forward. The hardest part was the burping of the system. 

I have a few upcoming maintenance work to do and will post these up when possible. Sometimes, I wish I could just pay someone to do the work for me, but I just don't trust anyone to work on my cars. Thankfully I have the tools and some skills to be able to do this myself, but it requires time and planning which is a pain when you're as busy as I am.

Anyways, thanks for your input as always and we'll catch up again soon.
Cheers mate 

 

[Novicebutnice]

On 10/13/2025 at 6:30 PM, Tony Prodigy said:

Hi Stephen,

A few things to consider here. 

I completely understand where you're coming from. Nobody want to harm their precious 2GR-FE engine, least of all me.

The factory fill coolant is specified to be replaced at 90 months or 150KLM from new according to the service schedule. (7 years). It can be done earlier if one chooses. Subsequent coolant flushes will then be substantially more frequent and this is 45 months after the original flush or 3.75 years, which also in line with AMD's advice in the above video. Once the system has been opened from factory, the potential for some contamination is increased and as such the service interval is reduced

 To eliminate any possibility of the coolant turning acidic, you should replace SLLC pink HOAT or OAT coolant at least every four years. Just remember though, HOAT and OAT coolants are not as aggressive as just plain glycol coolants. Those don't last and are recommended to be replaced every two years. 

If you recall, I actually did a PH test strip on my factory coolant when I drained it and it indicated no levels of acidity compared to the fresh coolant, so that was testament enough for me that the Toyota product is superior. Scotty Kilmer even recognizes Toyota's SLLC coolant as being the best coolants in the world and not being sponsored either, his opinion is highly valued by the car community world wide. That's enough peace of mind for me.

You also mentioned Nulon doesn't make water pumps, so the idea being that they have no agenda to sell you one if yours fails due to bad coolant. ?
Not sure if you know this, but Toyota don't make water pumps either. They're actually made by Aisin, which is a Japanese OEM manufacturing company.
The water pumps with the Toyota logo on them are actually Aisin pumps, so . I really believe Toyota wanted to create a coolant that is more superior than what was available at the time. They did start out with Toyota Red, and it was top notch, then pink for the newer engines.

That powdery residue you mentioned was also present on my overflow bottle. I could never understand how or why is was there either. I just assumed it was just some coolant that had somehow leaked out of the bottle when at a steep incline perhaps and then it just turned that way from the engine bay heat. I doubt it had anything to do with anything internal going bad. I don't think it's anything to be concerned about. I'd love to get the Car Care Nut's opinion on that actually..

A way to keep tabs on the health of your water pump seal is to check the weep hole from time to time. If it hasn't weeped so far and it's still original, then the coolant is doing its job. My water pump is still original and have no weepage as yet. I have also been under the car to inspect the mating surfaces of the head and block and nothing there either. Those would be the tell tale signs of an acidic system eating the alluminium up from the inside. Thankfully I did my coolant and won't have to worry about it for some time yet.

If you choose to go with non original coolant, then you'd need to really flush the system out properly to rid any traces of SLLC pink. You don't want to be mixing different chemical strains. Once completely flushed then you can just continue using that coolant of choice.
I stuck with original pink, because there was no way I could flush the entire system without being more invasive and considering it was still the factory fill, I felt confident it wouldn't present too much hassle going forward. The hardest part was the burping of the system. 

I have a few upcoming maintenance work to do and will post these up when possible. Sometimes, I wish I could just pay someone to do the work for me, but I just don't trust anyone to work on my cars. Thankfully I have the tools and some skills to be able to do this myself, but it requires time and planning which is a pain when you're as busy as I am.

Anyways, thanks for your input as always and we'll catch up again soon.
Cheers mate 

 

Hi Tony,

I thought needing to change the coolant more frequently (after changing the factory fill) had more to do with the old coolant not being flushed out?

As a result there is still some of the "old stuff" in there, which reduces the effectiveness of the new coolant?

I ended up going with Nulon RED in mid 2022 (including a flush), and changed it again about a month ago (again with another flush).

Sadly I don't currently have the facilities to do this work myself, so my mechanic did this for me and to date he has been very honest with me.

What interesting is that Nulon for their premix red has the boiling temp of 111 deg C (not under pressure), whereas an email from Nulon red concentrate mixed 50/50 is 107-109 deg C, I'm not sure if the difference is the assumed worst case scenario of not using demineralised water??

Nulon also starts with a higher PH compared with Toyota SLLC which also has a boiling temp of 108 deg C (not under pressure) 

"Toyota really couldn't be that diabolical to create a coolant which will inadvertently cause harm to your engine parts"

Cue evil CEO laughing GIF  😂

All jokes aside, many companies have gone bankrupt because their products were too reliable, and nobody needed to buy parts, or to replace the product.

So is there a possibility that Toyota would engineer a situation that causes a person to buy spare parts?

To me YES,

My car doesn't have changing the ATF in the service schedule...... It simply says inspect..... when there is no real way to inspect it, and I seriously doubt that this has ever been inspected by any dealership.....

Take care mate 🙂