Car Care Nut -Why you shouldn't wait 100k mi to change coolant on a Toyota UR series V8.

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I recently tested some coolant with strips ( https://www.amazon.com/dp/B01CNHJ4QI?ref=ppx_yo2ov_dt_b_fed_asin_title ).

One vehicle the Dexcool coolant was from 2008 and has ~26K on it and the other was GO5 from 2005 and has about 6K on it. Both tested out just fine. They also passed the voltage test. Does this mean it's still good?? I'm not 100% convinced they are.
I didn’t hear until years later not to use Dexcool in non GM cars. I mixed it with the existing Prestone green, when I replaced my Maxima’s radiator (turned into a mess contents dumped in driveway cuz it slipped). Nothing happened, that was 2015 and the car was junked 2023.
 
I didn’t hear until years later not to use Dexcool in non GM cars. I mixed it with the existing Prestone green, when I replaced my Maxima’s radiator (turned into a mess contents dumped in driveway cuz it slipped). Nothing happened, that was 2015 and the car was junked 2023.

You can use whatever you want, HOWEVER, you need to make sure a good system flush is done. I converted my GM car from Dexcool to GO5 and my ATV to GO5. In the process now of converting an old '73 Pontiac motor from the old school green stuff to GO5....well Peaks version of it.

https://www.owi.com/retail/brands/p...prediluted-for-north-american-vehicles---gold
 
His advice to cut the coolant change is sound IMO.
10 years is a very long time and whether it contributes to the head gasket or not is irrelevant. With liquid cooled EGRs and heater cores buried deep inside dashes, I’d rather not risk it.
People worry about a coolant bottle sitting in their garage for few years, but somehow, once poured into the cooling system, it’s good for a decade 🤔

Also, the head gaskets he showed all had erosions around all of the coolant passages, not just the one around the cylinder 5 and 7, so he may be correct that coolant somehow eats away the coating over time. It’s likely not cavitation, as it’s too far away from the pump, so that leaves either the chemistry or PH levels.
xOAT coolants have been proven to have a longer service life than IATs as well. They stay stable for longer, and organic acids/phosphates have shown to passivate metals more reliably than silicates in old American green coolant. Someone here said they’ll dump Dex-Cool in their company vans only if there’s a major cooling system repair like a water pump replacement.

The funny part is that silicated G-05 was used by Mercedes and they advocated for 3-5 year coolant changes, while many American cars at the time needed yearly coolant changes as the silicates would drop out. Toyota’s pink coolant and GM’s Dex-Cool(as well as Prestone Cor-Guard/Ford yellow and Dex-Clone AMAM) both use sebacate(sebacic acid per Toyota for their pink, sodium neodeconate for Dex/Prestone), Dex-Cool/Clone and Prestone uses it in combination with 2-EHA. But Toyotas tend to have more coolant issues with their pink, while GM worked out the kinks with Dex-Cool after they did a “drop-in” conversion on cars/trucks with the 3.1/3.4/3.8L V6s, as well a the 4.3L/5.7L Vortecs.
 
I didn’t hear until years later not to use Dexcool in non GM cars. I mixed it with the existing Prestone green, when I replaced my Maxima’s radiator (turned into a mess contents dumped in driveway cuz it slipped). Nothing happened, that was 2015 and the car was junked 2023.
Prestone, Peak and Safety-Kleen all claim Dex-Cool and their universal coolants are miscible with others. I wouldn’t risk it unless it’s an emergency.

Dex-Cool was the thing that enabled all make/all-models coolants. It met the Japanese no silicate requirement and the Euro no phosphate requirement.
 
Also, the head gaskets he showed all had erosions around all of the coolant passages, not just the one around the cylinder 5 and 7, so he may be correct that coolant somehow eats away the coating over time. It’s likely not cavitation, as it’s too far away from the pump, so that leaves either the chemistry or PH levels.

Or not-so-great gaskets...
 
Are you really using 100% coolant as the test strip appears to indicate?

Ed
No. Of course not. I’ve checked it with a refractometer. It’s 50/50. That is still factory fill.

Edit - checked again today, just to be sure - 53% on the refractometer.

I can’t explain the difference. A bit of evaporation, perhaps? I’ve never added water…
 
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Here is my coolant test strip from early August of factory fill Toyota/Lexus SLLC (pink) on my 2019 GX460 (1UR-FE) at 55k miles and approximately 5.5 years from build date. I drained and filled the radiator and topped reservoir with 1 gallon SLLC 2 weeks later (4 qts out of 16 or so). Did not do the block drains. Probably do either a couple more radiator d&f at next oil changes or maybe empty block drains.

IMG_1622.jpeg
 
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CCN is a great example of how things get distorted on the internet and people behave irrationally as a result. A couple of thoughts:

He is a very knowledgeable mechanic but he is not an engineer. Early in my career I had the opportunity to work alongside power train engineers at a very large auto company, but to be clear I was not there in an engineering capacity but rather as an attorney- I don’t want to overstate my experience. But I did come to appreciate the level of expertise it takes to become a powertrain engineer at a large auto company. Mechanics also have an impressive skill set and the good ones are very intelligent, but he is not really qualified to diagnose the cause, and his sample size is too small. So now he will have everyone changing coolant every 15 minutes because if you don’t you may not get 600k miles from your truck.

Second, how long do people expect a vehicle to last? I keep our cars for a very long time, but to make them reliable at a certain age - and I define that as being able to be taken and driven pretty much anywhere without packing tools, spares, rosary beads and food and water - it takes a lot of your time and money, or more of your money if you are paying a shop. People here obviously talk a lot about engines given the forum, but on a 200k mile car, everything needs to be checked and validated. So if the motor is shot at 200k for whatever reason, what kind of shape is the rest of the vehicle in, even one that is cared for?

Finally, why do people insist on buying a car like Toyota based on perceived reliability and durability but then question all of the service recommendations? I know that a little additional preventive maintenance is common and I do it myself, but to pronounce yourself a Toyota fan as well as a master tech and make videos generating lots of revenue claiming Toyota has a “big problem” here or there based on an n=1 (or some small number) sample is kind of idiotic and intellectually dishonest. Toyota is pretty conservative - their most reliable cars aren’t the most reliable because they hire geniuses and the other majors hire morons, it is because the designs are proven and have been in production long enough to get the bugs out. So in my mind the service recommendations are based on all of that experience. This guy gets clicks claiming this or that major problem based on inadequate service intervals, but if you watch he never gets to the point - his videos are way too long and rambling. That makes me question his agenda.

Backto the experience with the large car company - I learned pretty much every component on a vehicle, even a door handle, has an expected lifespan. So let’s say Toyota is conspiring to screw the customers with an inadequate coolant replacement interval that means the motors will be damaged by 200k. That means that the other components on the car, and certainly the major ones, have only been designed to last that long as well, so you are wasting your time because even if you could save the motor, there are about 3,000 other things they can and will wear out. This reality is consistent with the experience we have all had where cars start to go from “the one repair to the other” phase of life.

If I draw anything from this video, next time I am in the auto store I will buy some test strips. And if the motor on my Toyota develops problems at 200k, I will disclose the problem and sell it to someone who wants to roll their sleeves up with a 200k mile vehicle and I will move on. Dumping thousands of dollars into any vehicle with 200k miles is generally a fool’s errand.

Have a good weekend everyone. I am going to rebuild a carb on a 30 year old Briggs powered riding mower. I can’t stand small carburetors with all those little springs I have trouble seeing now so there will likely be some profanity involved.
 
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I just watched this again, he claims the coolant is so acidic it causes erosion yet there is no evidence of aluminum corrosion that would be indicative of acidic coolant. The gaskets he showed have erosion of the coating only at a very small hole close to the combustion chamber, IMO this not caused by acidic coolant but by increased velocity of the fluid at that point.
He mentions nothing about towing with these vehicles or how hard they are driven but greater expansion on the head at those cylinders due to an increase in temperature may be an issue. I am just an old mechanic and not a fluid dynamics engineer but if you are not seeing something like this in the aluminum on either the block or head it is highly doubtful it is from the coolant being acidic. JMHO
head corrosion.webp
 
CCN is a great example of how things get distorted on the internet and people behave irrationally as a result. A couple of thoughts:

He is a very knowledgeable mechanic but he is not an engineer. Early in my career I had the opportunity to work alongside power train engineers at a very large auto company, but to be clear I was not there in an engineering capacity but rather as an attorney- I don’t want to overstate my experience. But I did come to appreciate the level of expertise it takes to become a powertrain engineer at a large auto company. Mechanics also have an impressive skill set and the good ones are very intelligent, but he is not really qualified to diagnose the cause, and his sample size is too small. So now he will have everyone changing coolant every 15 minutes because if you don’t you may not get 600k miles from your truck.

Second, how long do people expect a vehicle to last? I keep our cars for a very long time, but to make them reliable at a certain age - and I define that as being able to be taken and driven pretty much anywhere without packing tools, spares, rosary beads and food and water - it takes a lot of your time and money, or more of your money if you are paying a shop. People here obviously talk a lot about engines given the forum, but on a 200k mile car, everything needs to be checked and validated. So if the motor is shot at 200k for whatever reason, what kind of shape is the rest of the vehicle in, even one that is cared for?

Finally, why do people insist on buying a car like Toyota based on perceived reliability and durability but then question all of the service recommendations? I know that a little additional preventive maintenance is common and I do it myself, but to pronounce yourself a Toyota fan as well as a master tech and make videos generating lots of revenue claiming Toyota has a “big problem” here or there based on an n=1 (or some small number) sample is kind of idiotic and intellectually dishonest. Toyota is pretty conservative - their most reliable cars aren’t the most reliable because they hire geniuses and the other majors hire morons, it is because the designs are proven and have been in production long enough to get the bugs out. So in my mind the service recommendations are based on all of that experience. This guy gets clicks claiming this or that major problem based on inadequate service intervals, but if you watch he never gets to the point - his videos are way too long and rambling. That makes me question his agenda.

Backto the experience with the large car company - I learned pretty much every component on a vehicle, even a door handle, has an expected lifespan. So let’s say Toyota is conspiring to screw the customers with an inadequate coolant replacement interval that means the motors will be damaged by 200k. That means that the other components on the car, and certainly the major ones, have only been designed to last that long as well, so you are wasting your time because even if you could save the motor, there are about 3,000 other things they can and will wear out. This reality is consistent with the experience we have all had where cars start to go from “the one repair to the other” phase of life.

If I draw anything from this video, next time I am in the auto store I will buy some test strips. And if the motor on my Toyota develops problems at 200k, I will disclose the problem and sell it to someone who wants to roll their sleeves up with a 200k mile vehicle and I will move on. Dumping thousands of dollars into any vehicle with 200k miles is generally a fool’s errand.

Have a good weekend everyone. I am going to rebuild a carb on a 30 year old Briggs powered riding mower. I can’t stand small carburetors with all those little springs I have trouble seeing now so there will likely be some profanity involved.
How long? Forever. “Until the wheels fall off.”

For my purchased new 1998 Maxima, it was junked in 2023. So forever at this juncture is the rest of my life.

That is not to say a vehicle can’t have a $5,000+ repair since cars are now six figures left and right. But to say oh, my flagship 2013 is shot in 2024 and to be junked? Nah, that’s not acceptable.
 
Just a thought. If TJ Hooker came across this scenario, he would dab a little coolant on his pinkie, and do the taste test. Now we could truly know how acidic SLLC is, or isn’t. There is a lot to be learned on tv. Lately I’ve been watching Rockford Files and Jimmy is a genius.
 
I just watched this again, he claims the coolant is so acidic it causes erosion yet there is no evidence of aluminum corrosion that would be indicative of acidic coolant. The gaskets he showed have erosion of the coating only at a very small hole close to the combustion chamber, IMO this not caused by acidic coolant but by increased velocity of the fluid at that point.
He mentions nothing about towing with these vehicles or how hard they are driven but greater expansion on the head at those cylinders due to an increase in temperature may be an issue. I am just an old mechanic and not a fluid dynamics engineer but if you are not seeing something like this in the aluminum on either the block or head it is highly doubtful it is from the coolant being acidic. JMHO
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This is an important point because getting to the root cause is often a combination of the engineering and real world use. There is "should be" but the real test is when the product gets into production and use.
 
How long? Forever. “Until the wheels fall off.”

For my purchased new 1998 Maxima, it was junked in 2023. So forever at this juncture is the rest of my life.

That is not to say a vehicle can’t have a $5,000+ repair since cars are now six figures left and right. But to say oh, my flagship 2013 is shot in 2024 and to be junked? Nah, that’s not acceptable.
^^^ This 100%... and my 24 year old Maxima was rust free which helps a lot with maintenance.
 
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This is an important point because getting to the root cause is often a combination of the engineering and real world use. There is "should be" but the real test is when the product gets into production and use.
To me 99% of the problem is that OEMs are so secretive.

-You rarely know if they're actually investigating a problem or sticking their heads in the sand. The latter is common because they don't want even internal documents hinting that they might have known about a problem. At least with safety issues this can lead to a recall.

-You rarely know if they've even acknowledged a problem (see above)

-If you're me, you're concerned about human ego. Individual engineers may be unwilling to admit they mighta made a dumb design (I personally believe this happens A LOT, with no data to support that belief)

Now, what would be awesome? If CCN reported that Toyota contacted him and they have had meetings (even virtual meetings) to investigate his concerns. Still, it's unlikely Toyota would ever publicly announce a design flaw and it might be equally unlikely CCN ever says Toyota showed him he was mistaken.

Typically, the only way an OEM ever acknowledges a flaw is through a design change or a short-lived run of a product (see Ford 6.0 and 6.4 diesels)
 
-If you're me, you're concerned about human ego. Individual engineers may be unwilling to admit they mighta made a dumb design (I personally believe this happens A LOT, with no data to support that belief)
Very valid point. About 16 years ago, an action I took cost the co over 1 mil dollars. The director set in motion the process to fire me. Would not meet to discuss.

I met with Bell Labs (virtually) and had them put in writing that my action should not have caused the issue that occurred and although they do no know the root cause from logging, they are certain that the equipment did not behave as designed.

Other folks in my then dept have been fired for covering up mistakes. I take the opposite road. And furthermore, when you have really bright people covering up? It’s difficult to determine what happened.
 
Does anyone know the rationale for keeping the original factory fill SLLC in for 100k or 10 years, but then every 50k miles thereafter (as opposed to 10yr/100k miles each time)?

Personally, I don’t mind spending $80 to $100 every five years on coolant, or similar amounts on oil, differential, tc, brake, transmission (ws), ps (atf) etc to maintain the gx460. I enjoy the diy aspect and figure I’m saving much more by not having the dealer do the routine services.
 
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To me 99% of the problem is that OEMs are so secretive.

-You rarely know if they're actually investigating a problem or sticking their heads in the sand. The latter is common because they don't want even internal documents hinting that they might have known about a problem. At least with safety issues this can lead to a recall.

-You rarely know if they've even acknowledged a problem (see above)

-If you're me, you're concerned about human ego. Individual engineers may be unwilling to admit they mighta made a dumb design (I personally believe this happens A LOT, with no data to support that belief)

Now, what would be awesome? If CCN reported that Toyota contacted him and they have had meetings (even virtual meetings) to investigate his concerns. Still, it's unlikely Toyota would ever publicly announce a design flaw and it might be equally unlikely CCN ever says Toyota showed him he was mistaken.

Typically, the only way an OEM ever acknowledges a flaw is through a design change or a short-lived run of a product (see Ford 6.0 and 6.4 diesels)
Toyota WILL NEVER investigate this unless it is safety issue and prompted by NHTSA. I seriously don’t understand this cult following of Toyota where people think they do things in interest of consumers. They left people hanging with junky transmissions in 2017, fixed the bug, but they never fixed 2017 transmissions in Sienna AWD and Highlander AWD as they were not prompted by NHTSA.
These V8 engines are out of production. Unless they have safety problem, there is absolutely no way Toyota is going to do anything about it. Why would they do something about out of production engine when NHTSA needed to push them to do something about 3.4TT? They tried to get away with that one, and those are in production.
And I am actually on the market for Sequoia with 5.7. Why? Bcs. size, real third row seat that actually I desperately need at this point, independent suspension in the back. My expectations? Like any Toyota I had: crappy brakes, cheap interior, fit and finish that is average at best. But whatever. Do I expect problems? Absolutely! Is head gasket issue worrisome? Yes. I researched a bit and it seems there are cases of failed gaskets, but there are cases of failures in all engines. Now, could this be serious issue? Absolutely. Toyota had issues like lift gates on Sienna for 2 generations without fixing it, repairs going up to $6000 and people still thinking it is vehicle without any flaws. But if you go to local dealership and check Sienna parts, you will see that they have lift gates in storage together with brake pads and spark plugs, for a reason. Same goes for sunroofs which is somehow $xxxx fix when drains clog. And Toyota never did anything about these issues to fix them on problematic models.
So, don’t hold your breath for any fix if there is real issue here, unless it is safety concern, which is not.
 
Does anyone know the rationale for keeping the original factory fill SLLC in for 100k or 10 years, but then every 50k miles thereafter (as opposed to 10yr/100k miles each time)?

Personally, I don’t mind spending $80 to $100 every five years on coolant, or similar amounts on oil, differential, tc, brake, transmission (ws), ps (atf) etc to maintain the gx460. I enjoy the diy aspect and figure I’m saving much more by not having the dealer do the routine services.
It's because what Toyota calls a coolant service, only consists of draining and refilling the radiator, which is only a partial change.
 
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