Is it critical to change coolant at 100K?

[RMcG]

I have a Yaris Hatchback, base model that has just turned past 100K. It is almost 11 years old. I was just looking at the maintenance schedule and the schedule says the engine coolant should be changed at 10 years or 100,000 miles.

I have to take an emergency road trip of about 1300 miles round trip (all interstate driving) in a couple of days.

Is it critical to change the engine coolant before I go on the road trip?

Would I be taking a big chance if I did not have the coolant changed until after I get back?

Thanks,

R.

[zoidberg444]

I actually ended up changing mine at 110,000 about 3 years ago as i was doing extremely high mileage that summer and fell behind on doing all the maintainance. I doubt 1300 miles will make much difference. You should do it when you get back.

I've done 170,000 miles now and my engine still works. I'm overdue for my second coolant change as they recommend 50,000 miles there after the first. I plan on doing it at my winter service in November. I think the coolant can start breaking down and causing corrosion if you stretch it to much.

Sent from my SM-T713 using Tapatalk

[ex-x-fire]

You'd be ok, I'd check the water pump for seepage. That's the time I'd change the coolant.

[tmontague]

I have a Yaris Hatchback, base model that has just turned past 100K. It is almost 11 years old. I was just looking at the maintenance schedule and the schedule says the engine coolant should be changed at 10 years or 100,000 miles.

I have to take an emergency road trip of about 1300 miles round trip (all interstate driving) in a couple of days.

Is it critical to change the engine coolant before I go on the road trip?

Would I be taking a big chance if I did not have the coolant changed until after I get back?

Thanks,

R.

you will be fine to change it out once you get back from the trip. The issue with coolant after a while is the corrosion inhibitors wear down as due the lubrication components and it becomes more and more like straight water in time. You can do this yourself with a simple drain and fill from the radiator petcock located on the bottom of the rad.

[RMcG]

Thanks to everybody. I don't have a garage, just the parking lot of the apartment I live in. I am inclined to do this myself if it is realistic for me to do this. The cheapest I can find anybody to do it for me at a garage is about $150 (USD). And I think it would be more if it requires flushing, rather than just replacement.

Is this something I can do myself pretty easily?

I was looking at some videos and they were talking about burping the system and other stuff which seemed complex. In addition, the maintenance schedule says it should be changed at 120 months (ten years) and the car is almost 11 years old. So I am thinking that maybe the age is factor in addition to the mileage of 100K.

I just went out and checked the coolant (engine cold). The coolant appears pink and clear, no rust or particulates. And it is about 1 inch above the "LOW" line on the plastic overflow tank.

Any other comments would be appreciated.

Thanks,

R.

[tmontague]

Thanks to everybody. I don't have a garage, just the parking lot of the apartment I live in. I am inclined to do this myself if it is realistic for me to do this. The cheapest I can find anybody to do it for me at a garage is about $150 (USD). And I think it would be more if it requires flushing, rather than just replacement.

Is this something I can do myself pretty easily?

I was looking at some videos and they were talking about burping the system and other stuff which seemed complex. In addition, the maintenance schedule says it should be changed at 120 months (ten years) and the car is almost 11 years old. So I am thinking that maybe the age is factor in addition to the mileage of 100K.

Any other comments would be appreciated.

Thanks,

R.

Do it yourself in the parking lot - here's how:

Buy a large oil drain pan (or equivalent plastic container) and slide it under the front of the car where the drain petcock in on the bottom drivers side of the rad. Look for a yellow plastic knob, you can reach it from the top of the engine bay. It may be stuck but be careful because you can break it.

Drain the coolant out from this pet cock (remove rad cap to speed this up and make sure coolant is not hot!). This will take 20 mins or so to fully drain, but once it stops draining close the pet cock and re fill with fresh Toyota coolant (50/50 mix) from the rad cap.

Fill until it over flows. Then squeeze both the upper and low rad hoses a few times and if the coolant level drops at the rad cap, re fill until it is at the top.

Keep the rad cap off and start engine. The coolant level will drop, refill it again until it is full and put rad cap back on then turn off engine. Make sure your overflow reservoir is full of coolant to at least the F line if not more.

Turn the car on and go for a drive. 20 minutes in current temps should be enough to get coolant up to operating temps, go for a jaunt on the highway and back.

Get back home and park the car. Check the coolant level in your overflow reservoir, it likely dropped some. Fill it back up to the F mark. Once your coolant is cool enough, remove the rad cap and if the coolant is not at the top then fill it to the top and replace the cap.

Drive the car as your normally would over the next week but after every day check the overflow reservoir and refill it so it is at the "F" mark. After a week of this you no longer need to keep checking it.

The yaris burps the air out of its cooling system very well by itself as the fill neck is properly situated as the highest point in the system. As it burps air itself it will pull coolant from the reservoir tank which is why you need to check it after you drain and refill the system.

Your only potential issue may be needing to use pliers on the drain petcock valve to crack it open. It is easier to do from under the car but can be done from above. Just be cautious not to crack it. Warmer temps help keep the plastic more pliable.

You can easily drain the overflow reservoir by removing the small diameter hose from the radiator fill neck. Once it is removed lower it in the engine bay so that is points into your drain pan. Once it is lower than the outlet on the reservoir, coolant will automatically drain from it.

[RMcG]

Do it yourself in the parking lot - here's how:

close the pet cock and re fill with fresh Toyota coolant (50/50 mix) from the rad cap.

.

Thanks tmontague for the detailed instructions and the encouragement. I plan to do it myself. It's not just the money, it's --- it's ---- it's, well it's being human.

ONE QUESTION: you say re fill with fresh Toyota coolant. Does that mean I should use a special Toyota brand coolant?

I added to my last post that the car is almost 11 years (131 months), whereas the maintenance schedule recommends a change at 120 months (10 years). But I checked the coolant and it appears pink and clear without particulates. And the level is about 1 inch above the "LOW" line on the plastic overflow container. So I think I am OK to wait until I get back from the trip.

Any more comments will be appreciated.

Thanks,

R.

[tmontague]

Thanks tmontague for the detailed instructions and the encouragement. I plan to do it myself. It's not just the money, it's --- it's ---- it's, well it's being human.

ONE QUESTION: you say re fill with fresh Toyota coolant. Does that mean I should use a special Toyota brand coolant?

I added to my last post that the car is almost 11 years (131 months), whereas the maintenance schedule recommends a change at 120 months (10 years). But I checked the coolant and it appears pink and clear without particulates. And the level is about 1 inch above the "LOW" line on the plastic overflow container. So I think I am OK to wait until I get back from the trip.

Thanks,

R.

Most of us YW member recommend Toyota brand coolant instead of other aftermarket brands. That being said, full disclosure - Toyota coolant here is only found in 50/50 mix and is not cheap. I found a company (Recochem) that makes various coolant for all different type of manufacturers and the name they brand it with is "OEM". It is sold locally to me and I can buy a pure concentrate that I mix myself with deionized water. I looked up the MSDS and the ingredient are essentially the same as Toyota's. I go with this instead of Toyota's own coolant and it has worked wonderfully for me.

I would recommend you look at getting Toyota stuff and if it is reasonably priced than stick with that.

Like I said before, you will be fine to do the coolant change after your trip. I doubt the corrosion inhibitors are fully depleted. If they were, driving isn't the issue, worn out coolant will eat away at your engine block regardless of driving or sitting in a driveway. Dip your fingers in the coolant and rub them back and forth, it should feel somewhat slippery.

[johnwk]

It wouldn't hurt to run a few gallons of distilled water through the system (following the same drain-fill-drive-drain procedure) before filling it with the new coolant.

I'm neither an expert nor a perfectionist, but I just used the Toyota-labeled Prestone stuff from the auto parts store.

A mini-tip: I found that only unscrewing the radiator drain plug part of the way prevented it from spraying all over the plastic under-engine guard (where it will collect and sit).

A word of encouragement for anyone considering doing this for the first time: changing my coolant following tmontague's instructions in another post was the first real job I ever did on any car ("real job" = something I would have normally paid someone else to do), and it really helped me to get over my fear of DIY maintenance.

[RMcG]

Thanks tmontague and johnwk and others,

I just checked the coolant by dipping my fingers in it and rubbing them together and it definitely feels slippery and oily.

Does anybody else have any suggestions as to the best way to dispose of the old coolant? I want to do this in an environmentally sound way.

Does anybody else have any feelings about using distilled water as a rinse as johnwk suggests?

Thanks,

R.

[johnwk]

You can take the old coolant (and dirty distilled water) back to the auto parts store. They will dispose of it for free.

[tmontague]

Thanks tmontague and johnwk and others,

I just checked the coolant by dipping my fingers in it and rubbing them together and it definitely feels slippery and oily.

Does anybody else have any suggestions as to the best way to dispose of the old coolant? I want to do this in an environmentally sound way.

Does anybody else have any feelings about using distilled water as a rinse as johnwk suggests?

Thanks,

R.

Around here our local municipal recycling centers take coolant for free to avoid people being a$$hats and dumping down the drain. Check online, some auto shops will also take it I have heard.

The only issue with adding water to the system to "flush" it is that you will dilute the coolant down below 50/50 as some water will stay in the system that you cannot fully get out. This may not be a problem depending on how cold your winters get. You can buy a tester for cheap to test your coolant when you are done to see what your freezing point is. I personally do this as I use a 10/90 coolant/water mixture in the summer for track use and a 55/45 coolant/water mixture in the winter. I test it to make sure my coolant can handle a bad cold snap throughout the winter.

IMO since you are just replacing Toyota coolant with comparable stuff I don't see a reason to need to flush it out or run water through it. I typically recommending doing that if the car has been given the wrong coolant, or if the coolant looks contaminated with debris or has been in use for way too long.

FWIW most owners never actually change their coolant unless their car breaks down and they need to. Even with this, Toyota's still seem to do well and run ok long term

[RMcG]

Thanks to everybody, especially tmontague. I think all my questions have been answered.

R.

[komichal]

Just a few notes from me:
- before you start draining out the coolant, set the cabin temperature knob to max
- by draining the coolant via the radiator petcock you will not get out everything. I can drain slightly over a half of the coolant only. There is a petcock on the engine that allows you to extract some additional liquid but it is a rusty one - IMHO not worth it (it is like 2-3 dcl only), especially when there is no chance to lift the car up
- I am draining and refilling the coolant once a year. I know it is waaaay too often, however it is a 20 minutes easy job and this way the "old" coolant that stays inside the car has no chance to get "too old".
- I agree that original Toyota coolant is naturally the choice number 1. However, I do not use it. I use Sheron Antifreeze G12 which can be bought already 50/50 mixed and the bottle costs around 7 USD (4 times less than original Toyota stuff). This Sheron product won in the test of several other brands available locally and it matches the specs required by Toyota.

[Mike Dexter]

Just a few notes from me:
- before you start draining out the coolant, set the cabin temperature knob to max
- by draining the coolant via the radiator petcock you will not get out everything. I can drain slightly over a half of the coolant only. There is a petcock on the engine that allows you to extract some additional liquid but it is a rusty one - IMHO not worth it (it is like 2-3 dcl only), especially when there is no chance to lift the car up
- I am draining and refilling the coolant once a year. I know it is waaaay too often, however it is a 20 minutes easy job and this way the "old" coolant that stays inside the car has no chance to get "too old".
- I agree that original Toyota coolant is naturally the choice number 1. However, I do not use it. I use Sheron Antifreeze G12 which can be bought already 50/50 mixed and the bottle costs around 7 USD (4 times less than original Toyota stuff). This Sheron product won in the test of several other brands available locally and it matches the specs required by Toyota.

I second this. Once per year, radiator drain and refill only. Then you are frequently cycling new coolant through, with little cost & time invested. In my experience, Toyota's are not very sensitive to whether or not you use OEM coolant. I use Zerex brand in my Yaris.

[tmontague]

Just a few notes from me:
- before you start draining out the coolant, set the cabin temperature knob to max
- by draining the coolant via the radiator petcock you will not get out everything. I can drain slightly over a half of the coolant only. There is a petcock on the engine that allows you to extract some additional liquid but it is a rusty one - IMHO not worth it (it is like 2-3 dcl only), especially when there is no chance to lift the car up
- I am draining and refilling the coolant once a year. I know it is waaaay too often, however it is a 20 minutes easy job and this way the "old" coolant that stays inside the car has no chance to get "too old".
- I agree that original Toyota coolant is naturally the choice number 1. However, I do not use it. I use Sheron Antifreeze G12 which can be bought already 50/50 mixed and the bottle costs around 7 USD (4 times less than original Toyota stuff). This Sheron product won in the test of several other brands available locally and it matches the specs required by Toyota.

good points - although I never understood everyone saying to put the heat on high. All this does is move the flap so the air passess over the heater core instead of bypassing it. This has no effect on coolant running through the heater core.

Have there been some past cars that had some sort of coolant heater core by pass when the hvac is set to cold air only?


It seems that a handful of manufacturers have come out with Toyota specific (Asian brand) coolant in the last couple years. Originally when I purchased my Yaris around 5 or so years ago, there really wasn't much options for aftermarket coolant other than green "universal" unicorn tears.

[komichal]

Have there been some past cars that had some sort of coolant heater core by pass when the hvac is set to cold air only?
I used to drive some older Mitsubishi and it really used to have some electric-controlled valves that enabled or disabled the coolant flow through the heatcore. It is probably pointless for Yaris, you are right. It is just an old habit that does nothing wrong on some cars and does something right for other cars. :)

[RMcG]

Is this Valvoline Zerex ZEREX DEX-COOL acceptable for a 2008 Yaris? Here is an Amazon link (https://www.amazon.com/Valvoline-DEX-COOL-Antifreeze-Coolant-Concentrated/dp/B0033QNZWS/ref=au_as_r?_encoding=UTF8&Make=Toyota%7C76&Model=Yaris%7C2851&Year=2008%7C2008&ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=1&vehicleType=automotive). ? Based on looking at the owner's manual, it looks like it is compatible.

I have also attached a screenshot that shows a check by compatibility with 2008 Toyota Yaris.

Here below is detailed information on the composition:

Valvoline ZEREX DEX-COOL antifreeze coolant is a patented* carboxylate formulation with a service life of up to five years or 150,000 miles. It incorporates state-of-the-art organic acid technology in an ethylene glycol base for protection of all cooling system metals including aluminum. ZEREX DEX-COOL antifreeze coolant is approved by General Motors to the GM 6277M specification. ZEREX DEX-COOL antifreeze coolant contains no phosphates, silicates, borates, nitrates, amines and nitrites. It can be mixed with any DEX-COOL and is approved by Opel, Dae Woo and Saab. It is dyed orange to distinguish its unique chemistry from traditional green and yellow silicate coolants. When diluted 50% with water, ZEREX DEX-COOL protects modern engine components from winter freezing and summer boiling. ZEREX DEX-COOL antifreeze coolant is storage stable for up to five years as both a concentrate or diluted with water. It contains a high quality defoamer and will not harm gaskets, hoses, plastics or original vehicle paint. Call 1-800- TEAM-VAL with questions. ZEREX DEX-COOL is formulated to meet or exceed the following antifreeze specifications and/or is recommended: ASTM D3306 SAE J1034, J814 SAE J1941 GM 6277M DEX-COOL APPROVED Siemens Wind Turbines Ford WSS-M97B44-D Saab, Opel Approved Scania, Volvo TMC of ATA RP-302B Federal Specification A-A-870A Navistar CEMS B-1 Type IIIA

[RMcG]

Here is an Amazon link (https://www.amazon.com/Valvoline-DEX-COOL-Antifreeze-Coolant-Concentrated/dp/B0033QNZWS/ref=au_as_r?_encoding=UTF8&Make=Toyota%7C76&Model=Yaris%7C2851&Year=2008%7C2008&ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=1&vehicleType=automotive). ? Based on looking at the owner's manual, it looks like it is compatible.

Here below is detailed information on the composition:

Valvoline ZEREX DEX-COOL antifreeze coolant is a patented* carboxylate formulation with a service life of up to five years or 150,000 miles. It incorporates state-of-the-art organic acid technology in an ethylene glycol base for protection of all cooling system metals including aluminum. ZEREX DEX-COOL antifreeze coolant is approved by General Motors to the GM 6277M specification. ZEREX DEX-COOL antifreeze coolant contains no phosphates, silicates, borates, nitrates, amines and nitrites.

The owner's manual says to use Toyota Super Long Life Coolant or a similar high-quality ethylene glycol-based, nonsilicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid organic acid technology.

It looks like this Zerex formulation meets the requirements, but I am interested in what others think. One of my doubts is that this Zerex formulation is orange and what I have in the car is pink.

Thanks,

R.

[zoidberg444]

I use the long life Toyota coolant mate. I'm to suspicious of other coolant brands to risk it.

Sent from my SM-G965F using Tapatalk

[RMcG]

I use the long life Toyota coolant mate. I'm to suspicious of other coolant brands to risk it.

Sent from my SM-G965F using Tapatalk

Thanks for your advice Zoidberg. I appreciate your advice. I read about your trek across Scandanavia. It is impressive.

R.

[RMcG]

It wouldn't hurt to run a few gallons of distilled water through the system (following the same drain-fill-drive-drain procedure) before filling it with the new coolant.
.

I plan to use Toyota Brand Coolant, 1 gallon of pre-diluted 50/50 costs about $23 (USD). The capacity of the cooling system is 5.1 quarts, but I think that perhaps much less than 5.1 quarts (perhaps a gallon or less) drains out of the cooling system when you open the plug/stopcock for a standard drain procedure.

So I am thinking that replacing the old coolant with distilled water and running the engine for a few minutes and then draining again (as suggested by johnwk in the quote), would get more of the old coolant out of the system before it degrades.

QUESTION: Does anybody have any comments or suggestions about this?

Thank you,

R.

[tmontague]

As i stated above, this will be fine but you will dilute your new coolant below 50/50 due to the water left in it. Make sure you test your coolant's freezing point once you swap it out

[RMcG]

As i stated above, this will be fine but you will dilute your new coolant below 50/50 due to the water left in it. Make sure you test your coolant's freezing point once you swap it out

Thanks tmontague. I did indeed read your previous post about how you run different dilutions and I am aware that the freezing and boiling points change with dilution. I was more worried, however, about the effect of dilution on the corrosion inhibitors and the lubricants.

I just bought two gallons at the local Toyota dealer, total cost with tax $50 USD. But my worries about corrosion inhibitors and lubricants may be moot, because according to the information on the coolant bottles, the 50/50 freezing point is only -34 degrees Fahrenheit. That is OK where I live now in the Pacific NW of the US, but if I go back to Montana, it is not OK. Because it can get to 40 below in Montana. I will have to call a Toyota dealership back in Montana and ask them what they sell for coolant.

Thanks,

R.

[RMcG]

... my worries about corrosion inhibitors and lubricants may be moot, because according to the information on the coolant bottles, the 50/50 freezing point is only -34 degrees Fahrenheit. That is OK where I live now in the Pacific NW of the US, but if I go back to Montana, it is not OK. Because it can get to 40 below in Montana. I will have to call a Toyota dealership back in Montana and ask them what they sell for coolant..

A busy airport in Montana recorded a temperature of 39 below zero in March of 2019, so this is not an academic consideration. I called a Toyota Dealer in Fairbanks, Alaska, and they use Toyota brand coolant 00272-LLAC01, which is undiluted. (I think this part number is off by one digit, see below.) It costs $30USD. They dilute this 60/40 with distilled water to get a freezing point of 62 below zero.

I think the actual number is Toyota 00272-1LLAC-01, see this amazon link (https://www.amazon.com/Toyoya-00272-1LLAC-01-ANTIFREEZE-GALLON-W/dp/B000ECIYAM/ref=sr_1_fkmr0_1?keywords=00272LLAC+toyota+coolant&qid=1561519440&s=gateway&sr=8-1-fkmr0).

I am not sure if this other part number coolant can be delivered to a local Toyota dealer here or not. But I will call tomorrow and find out.

Thanks,

R.

[RMcG]

I found a company (Recochem) that makes various coolant for all different type of manufacturers and the name they brand it with is "OEM". It is sold locally to me and I can buy a pure concentrate that I mix myself with deionized water. I looked up the MSDS and the ingredient are essentially the same as Toyota's. I go with this instead of Toyota's own coolant and it has worked wonderfully for me.



An undiluted OEM Reochem coolant (that is for Toyota, and is compatible with the Yaris according to the website) is sold through Rock Auto, see RECOCHEM 86174POEM (https://www.rockauto.com/en/moreinfo.php?pk=10579888&cc=1441505&jsn=1033&_nck=Ekt6BqBF1pwlXdx0gYlm1eLc36x7RagAV9qWoBGYzks2k IIGcMG6lE5GS9putP7wmUxgSGze%2FrPdR46WKSRoLyomJamzz G810PitvmOfG4gBYAKT%2Fiy1a5x6ntyyuI1feSuRe7sJJOghV gB6uflb01%2FMiUzmIAeCGIp5t2gBL7troKcma1hBuBdxvQ9fH PKg%2Fyrs6lga9NoXSqlQE0raNKno8Z1etMDejIqhDb6WPj1eI gFp5nGtbjY1n1wCOwjygYQ%2B28wD%2FZFFE3%2BTa%2F6rBkl jXzMRwM7zz%2FNE8skE9qC3IkoEXYusaJa%2B3LUKKE6nx8m5f KTAsi8SJS8AQC6A6FQcSoDC8zSqOnbIFqeBJX6mKtxesXL3Hke K5ajDhZHhKd8qdAKv1q7leD%2BtP4YguGg3gLEFBUw7)

I may buy this as I want to depress the freezing point more than -34 Fahrenheit, and it is also cheaper than the standard pre-diluted Toyota brand 00272-SLLC2 (I think is the correct number). Some websites like Amazon, Ebay and ToyotaPartsDeal.com sell the older undiluted coolant 00272-1LLAC-01 and some Toyota dealerships in cold parts of the US (e.g., Alaska) still stock this older undiluted (00272-1LLAC-01) coolant. These dealerships dilute the 00272-1LLAC-01 coolant 60/40 (coolant/distilled water) to get a freezing point of minus 56 Fahrenheit.

QUESTION: Does anybody have any opinion about whether the (apparently newer) Reochem would be better than the (apparently older) Toyota brand 00272-1LLAC-01 ? They are both undiluted and are about the same price.

Thanks,

R.

[tmontague]

I've used Recochem in diluted in every toyota I have ever owned with zero issues. The ingredients are virtually identical.

I mix my own coolant depending in what car it is going in (60/40 for my sis in laws yaris when she was up North for school, 50/50 for my Vibe and my yaris in the winter and 10/90 with amsoil coolant booster for my yaris during track season

Use it with confidence

[RMcG]

I've used Recochem in diluted in every toyota I have ever owned with zero issues. The ingredients are virtually identical.

I mix my own coolant depending in what car it is going in (60/40 for my sis in laws yaris when she was up North for school, 50/50 for my Vibe and my yaris in the winter and 10/90 with amsoil coolant booster for my yaris during track season

Use it with confidence

I just want to double-check, the dilution recipes call for diluting with "de-ionized water." Most of the de-ionized water sold on Amazon is pretty expensive, e.g., > $20USD per gallon. One of the Toyota dealers I talked to said they used distilled water (much cheaper ~ 1 USD per gallon).

QUESTION: Is using distilled water for dilution OK?

Thanks,

R.

[tmontague]

I used deionized because it is sold at my local Canadian tire but clearly states it is not potable. Distilled will be fine, iirc distilled has a slightly higher amount of dissolver salts still in it but it is a moot amount. Plus your coolant ratio is so high that you could use hard tap water and be fine as the coolant is meant to help with that issue

[fj40dave]

Well.....

I thought the coolant was like the fuel filter: Good for the life of the car......boy, I've been running on borrowed time!

235k on the original coolant for my '08 HB.....no issues!

I did just order the Toyoya 00272-1LLAC-01 ANTIFREEZE GALLON W from the link above.....thank you RMcG!

[RMcG]

It wouldn't hurt to run a few gallons of distilled water through the system (following the same drain-fill-drive-drain procedure) before filling it with the new coolant.
.......

A mini-tip: I found that only unscrewing the radiator drain plug part of the way prevented it from spraying all over the plastic under-engine guard (where it will collect and sit).



If I do decide to run distilled water through the system, how long should I let the system run in order to mix & help get the older coolant out of the system? Ten minutes? 20 minutes? Until the engine is hot?

(I know that there is the potential problem of diluting the coolant, since you cannot get all the distilled water rinse out of the system before you add the new coolant.)

Thanks,

R.

[johnwk]

If I do decide to run distilled water through the system, how long should I let the system run in order to mix & help get the older coolant out of the system? Ten minutes? 20 minutes? Until the engine is hot?

I would drive the car for a few miles, until it's warmed up, with the heat on full blast.


(I know that there is the potential problem of diluting the coolant, since you cannot get all the distilled water rinse out of the system before you add the new coolant.)

If you want, when winter approaches, you can do another quick drain-and-fill, which will reduce the dilution while also renewing a bit of the coolant. There's a very cheap and simple tool (https://www.amazon.com/Prestone-AF-1420-Antifreeze-Coolant-Tester/dp/B000BOA9RY) for testing the coolant dilution.

[RMcG]

I would drive the car for a few miles, until it's warmed up, with the heat on full blast.

Thanks John. But why is it necessary to put the heat on full blast?

R.

[voxtrot]

Do it yourself in the parking lot - here's how:

Buy a large oil drain pan (or equivalent plastic container) and slide it under the front of the car where the drain petcock in on the bottom drivers side of the rad. Look for a yellow plastic knob, you can reach it from the top of the engine bay. It may be stuck but be careful because you can break it.

Drain the coolant out from this pet cock (remove rad cap to speed this up and make sure coolant is not hot!). This will take 20 mins or so to fully drain, but once it stops draining close the pet cock and re fill with fresh Toyota coolant (50/50 mix) from the rad cap.

Fill until it over flows. Then squeeze both the upper and low rad hoses a few times and if the coolant level drops at the rad cap, re fill until it is at the top.

Keep the rad cap off and start engine. The coolant level will drop, refill it again until it is full and put rad cap back on then turn off engine. Make sure your overflow reservoir is full of coolant to at least the F line if not more.

Turn the car on and go for a drive. 20 minutes in current temps should be enough to get coolant up to operating temps, go for a jaunt on the highway and back.

Get back home and park the car. Check the coolant level in your overflow reservoir, it likely dropped some. Fill it back up to the F mark. Once your coolant is cool enough, remove the rad cap and if the coolant is not at the top then fill it to the top and replace the cap.

Drive the car as your normally would over the next week but after every day check the overflow reservoir and refill it so it is at the "F" mark. After a week of this you no longer need to keep checking it.

The yaris burps the air out of its cooling system very well by itself as the fill neck is properly situated as the highest point in the system. As it burps air itself it will pull coolant from the reservoir tank which is why you need to check it after you drain and refill the system.

Your only potential issue may be needing to use pliers on the drain petcock valve to crack it open. It is easier to do from under the car but can be done from above. Just be cautious not to crack it. Warmer temps help keep the plastic more pliable.

You can easily drain the overflow reservoir by removing the small diameter hose from the radiator fill neck. Once it is removed lower it in the engine bay so that is points into your drain pan. Once it is lower than the outlet on the reservoir, coolant will automatically drain from it.

Hi tmontague I am going to be doing a coolant drain and flush and replace the thermostat on my 2007 Yaris Sedan with Automatic Transmission for the first time. I just recently hit 160k miles and I do not think the coolant has been drained and filled before I bought it used. I am going to be USING THIS (https://www.pepboys.com/oem-antifreeze-concentrate-for-toyota-lexus-scion-with-pink-coolant/product/879899)
with distilled water. I will buy two gallons to flush or more until it comes out clear. Once it is clear how do you know how much of the concentrate to add with the clean distilled water already inside? Manual says 5 Quarts for Auto.
I don't know if everything comes out in the flush so do you have to wing it a little when adding the rest? Since it is hot here now would it be ok to have a little more distilled water inside radiator or reservoir? I don't want to damage the coolant system or engine since this is my first time doing this. Also worried about the left over air pockets damaging system after.

Thanks

[johnwk]

why is it necessary to put the heat on full blast?

Having the heat on will make the water flow through the heater core, further rinsing out the old coolant. If the system is properly filled, the heat will stay hot through your ride. If it cools off, there's unwanted air in the system.

PS. In my experience, it takes quite a lot of "burping" the upper and lower hoses to get all the air out while filling the system. Squeeze them each slowly and repeatedly until you don't see any more bubbles at the radiator neck. And over the next week or two, double-check the levels at the radiator neck and the overflow tank. If there was air in the system that escaped, you'll need to top off the coolant.

[tmontague]

Hi tmontague I am going to be doing a coolant drain and flush and replace the thermostat on my 2007 Yaris Sedan with Automatic Transmission for the first time. I just recently hit 160k miles and I do not think the coolant has been drained and filled before I bought it used. I am going to be USING THIS (https://www.pepboys.com/oem-antifreeze-concentrate-for-toyota-lexus-scion-with-pink-coolant/product/879899)
with distilled water. I will buy two gallons to flush or more until it comes out clear. Once it is clear how do you know how much of the concentrate to add with the clean distilled water already inside? Manual says 5 Quarts for Auto.
I don't know if everything comes out in the flush so do you have to wing it a little when adding the rest? Since it is hot here now would it be ok to have a little more distilled water inside radiator or reservoir? I don't want to damage the coolant system or engine since this is my first time doing this. Also worried about the left over air pockets damaging system after.

Thanks

You won't ever know exactly how much concentrate to add - which is why you always mix a concentrated coolant with water before you add it to the car.

And that is also why I said you can just simply drain and re fill as you likely will not have any benefit of a flush.

If you are set on flushing it, then just run water through it until it comes out clear. Then start adding the coolant that you premixed in other jugs until the rad is full. Over fill the overflow reservoir a bit as well.

Squeeze the rad hoses a bit and you will see the coolant level drop a bit in the radiator. I typically jam a funnel in the radiator fill hole and over fill the funnel and then turn the car on, you will see the level drop a bit and then start to rise as it warms up. Once the car is off it cools and starts dropping. Go back after 30 mins and remove the funnel and top up the rad. Drive your car will an over filled overflow reservoir and check it every day as it will drop as air ir burped out of the system. This will stop after a couple days.

In my experience with various Yaris', they bleed air from the cooling system really well, just make sure the front end is jacked up so the rad cap is the highest point of the engine.

Once this is done you need to buy a tester to make sure the freezing point is well below anything that you will see in your climate. You will have more than enough coolant in there for the summer, but potentially not enough for the winter, depending on your climate. Most of the coolant is removed when you drain the rad, but a slight amount will still be left in there.

FWIW many people say you need the fan to turn on to open the thermostat - this is wrong and a waste of time. The T-stat opens at 180F, well before the fan kicks on (typically 204F). Also the Tstat is not an all or nothing mechanism, it will slowly open just prior to 180F and fully open around 180F. I have successfully bled cooling systems in ambient temps way to cold to get the fans to turn on.

I just finished draining and re filling my Subie Outback and when the fans actually kicked on the coolant level didn't even drop - this is because the Tstat was already wide open well before the fans kick on.

[toyotavios_11]

150000km or 10 years whichever come first and subsequently every 50000km or 5 years whichever come first

[RMcG]

And that is also why I said you can just simply drain and re fill as you likely will not have any benefit of a flush.

If you are set on flushing it,

I value what tmontague is saying here about a flush being of doubtful value.

I am still kind of undecided whether to just simply drain and re fill or to flush. A flush will mean extra time and effort. How much extra time and effort is involved in the flush?

I talked to one mechanic at a Toyota dealership and he said they do not do a flush unless it has been a very long time since the coolant was changed, the change is long overdue and there is evidence the coolant has begun to degrade: e.g., coolant no longer "clear," but has particulate matter present in the coolant, etc.

It seems, however, that there would be some degradation of the old coolant that remains after drainage (because some old coolant remains in the system after drainage), even if you cannot see the degradation (e.g., particulate matter, etc).

QUESTION(S): Does anybody have any objective evidence a flush will be of benefit or no benefit?

Does anybody have a lot of experience with this question?

Thanks,

R.

[tmontague]

I'm doubtful there will be any objective evidence floating around.

I've been wrenching on old used cars for year - I buy them at their lowest price and put a lot of time into them so that I can be sure they are safe and comfortable for my family and last another 5 years at least. I end up with a great car fir pennies on the dollar.

One thing I've learned is what is useful and what is just wasting time and money. Coolant flush on proper oem fluid that appears fine is a waste. I have only flushed my yaris when I got it because it had green coolant in it.

I used to drop trans pans and swap out filters when I changed trans fluid. Every single time the filters were completely clear (all fine functioning trans, not blown apart). So now I just do a fluid "flush" using the trans cooler line. Saves me time and money on something that has shown no benefit.

In the end of the day it is your time and money so do what makes you sleep at night. But trust me when I say that a flush is a practice in futility in your case. This is coming from someone who is objective data driven and applies real world experience the best that I can to that. Ie: using 0w20 oil on the track amidst the cries of tradition