Wife has a 2011 Honda with the dashboard “maintenance minder,” which is supposed to helpfully remind you when various maintenance items ought to be done.
The problem is that the maintenance minder keeps an eye on mileage, but not time, and my wife doesn’t drive the car much. It’s now five years old, with less than 25,000 miles on it. The owner’s manual indicates that when a “5” appears in the maintenance minder window, the engine coolant is supposed to be replaced. (there is no connection between that number “5” and the fact that the car is five years old; it’s just one in a list of six maintenance items.)
Haven’t seen a “5” yet. No mileage or time interval is indicated in the owner’s manual. With low miles, but 5 years of service, should the coolant be replaced at this point? ISTR previous cars specifying ~5-year coolant life.
I would replace it, because the stuff does break down, and you do lose a little even in the best of closed systems.
FWIW, how often you replace it in general depends partly on the life of the car. When I drove a 22-year-old car, I replaced it every two years, because cars that old have more leaks, hot spots, and soforth, also, more rust and stuff getting into the fluid. More potential exchange with the oil, etc. This car had 124,000mi., which was very low for its age, but the radiator and engine were all original parts, except the hoses.
I had an even older car once, albeit, it had a newer (junkyard) radiator, and I replaced that every year.
When you replace the fluid, consider using low-tox. If the car springs a leak, or for whatever reason, the fluid gets into water someone’s pet drinks or child plays in, the low-tox, while not non-tox, is a lot safer. It takes only like a tablespoon of the regular stuff to kill a large dog. A teaspoon can kill a small child. With the low-tox, they have to drink like half the bottle. It costs about 3x as much, but that’s like $6 vs. $2 a gallon.
I always put low-tox in my vehicles. Stuff happens, like front-end collisions that are not your fault, that can end up in high-tox stuff spilled everywhere.
modern hybrid-organic acid (H-OAT) coolants generally are rated to maintain corrosion protection for 80-100,000 miles, but may lose freeze protection before that.
older silicate antifreezes (the classic “green stuff”) was usually only good for 30,000 miles or so as the silicates would form deposits and lose corrosion protection.
As far as “how”, get a good maintenance manual and follow the directions exactly. There’s some “gotchas” in many car engines and missing just one could trash it. I like Haynes Manuals, a worthy investment.
When it tests poorly. Coolant can be tested by an adequately sophisticated shop. If it isn’t broken down in either cooling or (more commonly) corrosion protection, it doesn’t need to be replaced. It’s kind of nasty stuff to dispose of, so extra effort to not add it to the waste stream is worthwhile.
I think you’re mistaken here. Do you have a cite? In 40+ years of professional auto repair I have never heard/read/seen anyone claim that antifreeze mixtures can lose their freeze protection.
Antifreeze will lose its corrosion protection, as you said, due to the anti-corrosion additives being consumed doing their job. But the freeze/boil protection is in the basic chemistry of the mixture, akin to salt water having a lower freezing point than plain water. Unless the mixture is altered by adding just water or just antifreeze, its freezing point will not change.
My repair info shows a coolant change interval of 120,000 miles. While it may need to be serviced before it reaches that mileage, I wouldn’t worry about now. I suspect it can go several more years before it’s due.
The mileage/time intervals in the factory schedule are averages, typically on the conservative side. As Amateur Barbarian mentioned, the way to determine whether a particular car is due or not is to test the coolant, specifically its pH.
According to Honda, apparently it shouldn’t be changed yet. As you note, the owner’s manual says to change it when the service minder tells you to change it.
I’m not sure which model you have but interestingly, the 2011 Honda Accord has a 5-year, 60,000 mile powertrain warranty. The owner’s manual also says to use only Honda Long-life Antifreeze/Coolant Type 2, except in an emergency, when you can use another non-silicate coolant. If you do that though, it also says to flush the temporary coolant out and replace it with the Honda coolant. Thus, they require you to use a branded coolant. Presumably, if you failed to use a branded coolant, they would have grounds to void your warranty claim if a coolant failure caused problems with the car.
Under the Magnuson-Moss Warranty Act, 15 U.S. 2302(c) (https://www.law.cornell.edu/uscode/text/15/2302), a manufacturer of a consumer product can’t condition your warranty on your using particular branded services or supplies unless they are willing to give you the supplies at no cost (or otherwise receive an exemption from the Federal Trade Commission). So, based on what Honda’s owner’s manual says, Honda would have to give you the coolant for free if they expected that earlier coolant maintenance would be necessary to keep your warranty.
Putting two and two together, I predict that the maintenance minder will tell you to change the coolant only after the car is out of warranty. One commenter on this not-authoritative site says that the Type 2 long-life coolant should be good for 100,000 miles or seven years. (Coolant change interval | Drive Accord Honda Forums). If that’s right, your coolant maintenance minder should be expected to trigger based solely on the age at seven years. Unless your car was a dusty dealer relic you bought after the end of the model year, the six-year warranty term will have lapsed and it will be out of warranty before the coolant maintenance minder tells you to change it. So Honda won’t ow you the free coolant. This is a little sneaky. Once the warranty is over, I wouldn’t feel compelled to use Honda coolant, but I would stick with extended-life, non-silicate coolant designed for aluminum engines.
Honda does insist on brand name or compliant coolant, and from hanging out in Honda land, I have heard enough stories that I believe it’s for a reason. I wouldn’t try to save $10 on a once-per-years maintenance step.
Is there any suggestion to change it at a certain age? I understood that the anti-corrosion additives broke down with time in addition to mileage so both would be relevant, particularly for a low-use car like the OP’s.
I like to live dangerously. In truth, this is probably better advice. You really would only save about 10 or 12 bucks. It’s probably not worth the risk. I do wonder how many of those stories though involve coolant that was not only non-Honda but also contained silicates or was otherwise not formulated for aluminum engines.
There is a school of thought which maintains that if you go too long without flushing the radiator, then you’re better off not doing it altogether. Thinking is that as things age all sorts of gunk works its way into various connections and seams, and at that point if you flush them out you’ll get leaks. So you either flush the system and get rid of the gunk before it has a chance to build up altogether, or not at all.
Not a mechanic here so I can’t really say, but this theory is out there.
AFAIK, the Magnuson-Moss act basically specifies that they can’t require you to use specific branded products in order to fulfill warranty requirements. However, they can require that whatever you choose to use meets certain specifications to qualify for warranty coverage. Car manufacturers do this all the time.
For example, my truck requires ATF+4 transmission fluid. During the warranty period Chrysler didn’t care if I use Mopar, Valvoline, Walmart Supertech, or any other ATF+4 rated transmission fluid. But if I’d used something else, I’d have voided my warranty.
That said, the main problem appears to be that there aren’t any other coolants on the market that meet the Honda Type 2 spec, so you’re stuck using the OEM Honda coolant, or you can take a chance with something like Zerex Asian Car formula coolant.
No, this doesn’t make sense. The coolant gets progressively more acidic, so not changing it once it becomes due hastens the corrosion that eats away at metal components. Leave it in there and you can count on leaks developing, gunk or no gunk.
Now, what you’ve related is old wisdom for automatic transmissions. Automatic transmission fluid is highly detergent – a transmission fluid lead trail will typically be clean, where a motor oil trail will be grimy. If servicing has been put off so long that the deteriorated fluid formed varnish that helped seal some critical internal passages, then the addition of a large quantity of fresh fluid could clean the varnish to where certain operating pressures were no longer obtainable. There have been cases where a car is driven into the shop, the tranny fluid is changed, and the car won’t drive out. Shops learned to not change the fluid if it was black, that being the indicator that it might have reached the varnish deposit stage.
What about the coolant’s lubricating properties? When does that degrade? I don’t think anyone as of yet has mentioned that, for the water pump bearings.
The car is equipped with an automatic maintenance minder. The manual basically says “when the car displays this number, do this maintenance item.” No reference to time/distance in the manual, except for a few things like changing the air filter more often if you drive in dusty conditions a lot, or bleeding the brakes every few years.
The coolant normally never touches the water pump bearings (if it does reach the bearings, the water pump is leaking and the bearings’ days are numbered). Any lubricant in the coolant is intended for the seal in the water pump, and is probably only of any help if the coolant formula includes silicates. I’ve never seen anything about how long it lasts.