Do I have to change my coolant?

[DeeSull]

Owner's manual for a 2018 Honda Fit says to perform coolant service every 5 years or 50,000 miles.

But the car runs fine and has never overheated. Coolant levels in both the radiator and expansion tank are good, and I haven't had to top it off. Radiator cap is clean, still springy, and seals fine. The (original Honda) coolant is blue, transparent, and clean: no cloudiness, no oil, no rust, no debris, no signs of contamination. Hoses are tight, no cracks, no bulges, no signs of leaks, rubber is supple.

I got a pack of the Phoenix Systems Coolant Strips and tested the coolant from the top of the radiator. According to the most recent test strip, the pH is between 8 and 9 (i.e. still alkaline), and glycol% is between 50% and 60% (i.e. estimated freezing point below -34F, boiling point about 265F). I test every six months, and plan to drain/fill the coolant when the pH drops below 8 or glycol goes below 50%.

Is there any reason not to trust or rely on the coolant test strips? What other factors should be considered?

 

[eljefino]

Factor the cost of the coolant, the hassle of disposal, and the hassle of burping the air out of the system. I'd do it because Honda says to do it.

 

[rstcso]

Owner's manual for a 2018 Honda Fit says to perform coolant service every 5 years or 50,000 miles.
Is there any reason not to trust or rely on the coolant test strips? What other factors should be considered?

Is this a car you plan on keeping for many more years? If so, I'd be changing the fluids per the owner's manual... at a bare minimum.

Coolant is the water pump's lubricant.

We have a pool, and test strips are highly inaccurate compared to using reagents.

 

[supton]

Coolant has anti-corrosion inhibitors which break down over time, if I'm not mistaken. Same color but not the same protection, as age and heat takes its toll. Do your test strips test for that? Or is being alkaline good enough to prevent metal erosion?

I don't know if it is as easy as doing a drain and fill but that goes a ways to refreshing those inhibitors and (hopefully) making the radiator and heater core last all the longer.

Hoses though seem to last forever now. Low on my list of worries.

 

[slacktide_bitog]

Change it.

Zerex Asian Blue, Pentofrost A3, Peak OET Blue, or Recochem Blue

 

[DirectRejection]

Change it.

Zerex Asian Blue, Pentofrost A3, Peak OET Blue, or Recochem Blue

Seven years.
Yes change it.
Now.

 

[zrxkawboy]

Coolant has anti-corrosion inhibitors which break down over time, if I'm not mistaken. Same color but not the same protection, as age and heat takes its toll.

Correct. Freeze protection stays, but corrosion protection is reduced over time.

 

[Carmudgeon]

Factor the cost of the coolant, the hassle of disposal, and the hassle of burping the air out of the system. I'd do it because Honda says to do it.

Compare that to the cost and hassle of replacing a corroded radiator, or heater core, which needs to be extracted from inside the dash.

Penny wise…

 

[edyvw]

Owner's manual for a 2018 Honda Fit says to perform coolant service every 5 years or 50,000 miles.

But the car runs fine and has never overheated. Coolant levels in both the radiator and expansion tank are good, and I haven't had to top it off. Radiator cap is clean, still springy, and seals fine. The (original Honda) coolant is blue, transparent, and clean: no cloudiness, no oil, no rust, no debris, no signs of contamination. Hoses are tight, no cracks, no bulges, no signs of leaks, rubber is supple.

I got a pack of the Phoenix Systems Coolant Strips and tested the coolant from the top of the radiator. According to the most recent test strip, the pH is between 8 and 9 (i.e. still alkaline), and glycol% is between 50% and 60% (i.e. estimated freezing point below -34F, boiling point about 265F). I test every six months, and plan to drain/fill the coolant when the pH drops below 8 or glycol goes below 50%.

Is there any reason not to trust or rely on the coolant test strips? What other factors should be considered?

Wait until it overheats, then change it.

I mean, it is scheduled maintenance. Change it. Coolant serves as an anticorrosive fluid and as a lubricant for the water pump.

 

[JimPghPA]

Besides transferring heat, and not freezing in winter, coolant lubes the pump, and has to not alow electrons to flow between dis-similar metals, and also not cause corrosion itself. It does get exposed to air in the expansion tank, and some flows out of the system into the expansion tank when it's hot, and then flows back in to the system from the expansion tank when it cools.

I don't know if it's still the case with today's coolants, but about 35 years ago, a retired Mercedes mechanic told me that coolant is made from plant based chemicals, and initially it is an acid. Other chemicals are put into it during production to neutralize that acid. And over time those chemicals loose ability to neutralize the acid and it becomes acididic again. He told me that if you ever open the Radiator cap of an old vehicle and everything looks clean and good, to change the antifreeze because there's a good chance it looks good because the antifreeze had become acidic and is cleaning while also attacking everything.

The yt mechanic called the car care nut says Toyota head-gaskets go bad if the antifreeze is not changed. There is very little space between the coolant passages and combustion cylinder in the head-gaskets of some Toyota engines.

----------------

BTW, honda says never flush with any types of flush, and never add tap water. Doing so introduces some ionized molecules to the cooling system and that allows corrosion.

Just drain and fill with Honda pre-mixed coolant, or the coolant hond used in that vehicle.

I know for my 2016 CRV it's 100,000 miles or 10 years. But after that it's only half of that because not all of the previous comes out during the drain.

My CRV was made in October of 2015 and I did a drain and fill using hond premixed 2 years ago.

Get a Leslie Radiator funnel kit ( or the equivalent ) to fill and burp out air. They work great.

 

[ripcord]

Go ahead and change it. The ethylene glycol itself doesn't go bad, but it does gradually get dirty and the additive package needs to be refreshed periodically. You don't have to make it complicated. Just drain the radiator and refill with blue Asian style coolant. Any kind that says Honda on the label is fine.

 

[Lubener]

I always change mine based on time not mileage. You are two years overdue. The anti corrosive additives are what get depleted and running longer, you will risk corrosive damage to the engine and cooling system.

 

[daniel327]

Because I'm lazy, I use an Australian brand of coolant called Nulon One Coolant. It's allegedly good for 1,000,000 kms (~625,000 miles) or 10 years.

 

[Sumboodie]

Because I'm lazy, I use an Australian brand of coolant called Nulon One Coolant. It's allegedly good for 1,000,000 kms (~625,000 miles) or 10 years.

Same, though I use Delo ELC. Get a great price through work.

 

[CharBaby]

Yes, you have probably pushed two years further than you should have but I’m sure no damage is done.
I would change it now and continue on a five-year cycle regardless of mileage because it’s the right thing to do.
Why wait for problems & to happen. This is called preventive maintenance.

 

[Averroes]

Every 4 years for me, regardless of brand or operators manual. Yeah, the engineers and chemists know more than me, they also operate under the crack and whip of the accounting/finance bros (aka me), so I don't trust their words for longevity.

It's cheap insurance for your water pump, radiator and engine.

 

[Kira]

Drain and fills BEFORE the coolant becomes depleted. It's really easy now-a-days.

Also, a Q:
Many have said that today's water pumps' bearings are isolated from the coolant flow and are NOT lubed by the coolant.
I don't know if this is true or not.....but I've heard it a lot.

 

[Boomer]

If your coolant flows through the expansion tank, do what I do. About 5-6 times a year, I suck out the contents with a turkey baster and refill with new coolant. After 8.5 years, my coolant is fresh and zero crud or film in my overflow tank. The tank gets so hot when driving, it is hard to touch so I know coolant flows through it.

 

[nbpt100]

Good responses here. How do people dispose of old coolant?

 

[scrllock]

Good responses here. How do people dispose of old coolant?

County hazardous waste disposal. Next to impossible to find a parts store that takes it.