What's Harder On Modern Coolant... Time Or Miles?

[silversport]

would checking the coolant/antifreeze for color and clarity, check with a coolant tester (the rubber bulb end type) for freeze and boiling protection, using a multimeter to check for electrolysis and using pH strips to check for coolant/antifreeze pH...is this enough or do you all stick to a time and/or mileage schedule regardless?

Bill

 

[billt460]

would checking the coolant/antifreeze for color and clarity, check with a coolant tester (the rubber bulb end type) for freeze and boiling protection, using a multimeter to check for electrolysis and using pH strips to check for coolant/antifreeze pH...is this enough or do you all stick to a time and/or mileage schedule regardless?

Bill

I don't live in a freezing climate, so I never test the freeze / boil protection. On my truck I flush it enough to where it really isn't necessary. However it takes the older, inexpensive green Prestone concentrate.

I have never used test strips. Perhaps I'll try them. They certainly can't hurt. I now have 5 gallons of concentrate for my Jeep, along with 5 gallons of 50/50 premix for my Toyota. So I'll just do as I mentioned. Suck and remove, then refill and drive.

After several "suck & fills", I'm sure the condition of the coolant will be good enough so it will no longer be a concern. On my truck, I'll just keep draining and flushing it like I have been all these years.

It's easy to do because everything is easy to get at. I can even disconnect the overflow tank, drain and flush it with a garden hose while everything else is draining.

 

[kris42]

Check with test strips, if it passes don't change it as simple as that.

 

[nthach]

IMO, flushes have a time and place - especially if coolants were mixed(ie, green silicated with modern xOAT), BHGs/trans cooler failure introducing oil into coolant, Dex-Cool gasket failures and neglect. In those cases, a chemical flush, followed by detergent if needed works fine.

Else, if the cooling system has been maintained with the right coolant and no cooling system failure happens, a drain-fill is all you need to you.

 

[FCD]

The inhibitors in modern OAT stuff last a veeeery long time, really the only reason to change it is to ensure it remains alkaline ( IAT coolants tend to be more Alkaline )
And the same goes for the modern HOAT coolants, while the Inorganic inhibitors deplete more quickly, the coolant always has the OAT "Backbone"

 

[DAVIDO49]

My 2015 Jeep Grand Cherokee only has 16,000 miles on it. It's still running the original coolant. It's going to be a LONG time before that vehicle ever sees 100K miles. (Which is supposedly how long the coolant lasts).

So... When should I start thinking about changing the coolant? How long does coolant last before it starts going "bad"? Is this newer stuff that great compared to the older yellow / green Prestone?

That's what my 1991 F-150 runs, and I've changed that coolant every 2 years. It's still running the original 31 year old heater core. And the radiator is close to 25 years old. So I must be doing something right.

My gut feeling is to change it out. But it's going to be a bit of a PITA to do it. It's not easy getting to the drain plug. And just looking at You Tube videos on the subject, there is talk about, "bleeding the air from the system"... (5.7 HEMI V-8)... Something I've never done on any vehicle after a coolant change. The air always seems to work it's way out of the system after a few heat / cool down sessions.

Where is a good place to buy this newer coolant besides the dealer? They rape you on everything. Or should I let it go for a while? It's been in there for 7 years.

That's a question I've pondered myself as my 04 Mustang Cobra 32V 4.6L DOHC supercharged engine ..has 4900orig mis an obviously not driven very often

 

[Vern_in_IL]

I would say miles, because there is not an expiration date on coolant jugs!

 

[akbrian]

I would say miles, because there is not an expiration date on coolant jugs!

I know I after deep diving on Zerex heavy duty antifreeze specs recently, I know the Zerex has "shelf lives" varying from >1 year (traditional green) to > 35 years ( HD Nitrite free ELC Red).

 

[billt460]

I know I after deep diving on Zerex heavy duty antifreeze specs recently, I know the Zerex has "shelf lives" varying from >1 year (traditional green) to > 35 years ( HD Nitrite free ELC Red).

I would love to see what that crap looked like, after cooking in a radiator for 35 YEARS.

 

[doublebase]

Theoretically, if a pocket of air gets trapped in a coolant passage, it can cause that portion of the block/head to heat up significantly more than the surroundings. In extreme cases this can cause cracked blocks or failed head gaskets. Sort of an issue on some VQ products.

Also, trapped air does not always come out after a few heat cycles. Some cooling systems are just not friendly to self-purging.

I’m not sure if you’ve mentioned this also, but air theoretically can also effect the pump. And stop it from moving coolant. I think that’s possibly the biggest concern. A vapor locked pump. No flow=goodbye engine.

Ive never seen it happen, but years ago the Ford police cruisers weren’t exactly easy to bleed and you had to be careful of vapor lock. My wife’s Mercedes isn’t exactly fun either. And my own 2016 Toyota Avalon has a pretty peculiar bleeding procedure, involving a bleeder screw, over flow funnel, high rpm’s and clear 1/8th hosing. Watched the “Car Care Nut“ demonstrate it. Tried it myself...not sure I’ll do it that way next time.

 

[doublebase]

Time or mileage, tough question.

Not sure, but I always tent to lean towards mileage with everything just because of the act of driving, all the strains of driving...temperature cycles, weather, extreme conditions, salt, dirt, combustion...all are influences??

 

[Trav]

 

[akbrian]

I would love to see what that crap looked like, after cooking in a radiator for 35 YEARS.

Shelf life, not in service life. Still if you're doing a 5 year change period, it would be nice to know whatever you had left over from the previous change is still good in bottle. The oddity of that product is that I can't actually find it listed for sale anywhere. The specs look great though. I'm a little confused though, do you think it is crap?, or that it would look like crap after being in service for 35 years?

 

[billt460]

............... I'm a little confused though, do you think it is crap?, or that it would look like crap after being in service for 35 years?

To be honest, I wouldn't be too keen on either. I doubt I would waste my time with ANY coolant that was 35 years old. On the shelf, and certainly not in a radiator.

This stuff isn't that expensive to even mess with, assuming it's that old. And if you think about it, this stuff hasn't been out that long, for them to be making predictions that it's going to last over 3 decades. Talk to me in another 20 years..... Assuming that I'm even above ground by then.

 

[Vern_in_IL]

^Well that was before the "bitter flavoring agent" was added. So it is dangerous.

 

[akbrian]

To be honest, I wouldn't be too keen on either. I doubt I would waste my time with ANY coolant that was 35 years old. On the shelf, and certainly not in a radiator.

This stuff isn't that expensive to even mess with, assuming it's that old. And if you think about it, this stuff hasn't been out that long, for them to be making predictions that it's going to last over 3 decades. Talk to me in another 20 years..... Assuming that I'm even above ground by then.

I think the point is that the phosphates don't (apparently) fall out of solution easily. Really, the shelf life of any coolant is going to be related to ingredientes falling out of solution more than anything else. Silicates do that quickly, for example.

 

[willbur]

Thanks for that video. However, assuming no electrolysis going on due to dissimilar metals, this test may miss corrosion that is?

 

[silversport]

use fish tank pH strips to check that too as well as a visual check of the coolant...and a coolant/antifreeze hydrometer type tester...what else might you be missing when determining if your fluid is good???...

Bill

 

[Doc8404]

I see lots of you changing your own coolant. That’s one thing I don’t do due to collection and disposal. PITA.

 

[billt460]

I see lots of you changing your own coolant. That’s one thing I don’t do due to collection and disposal. PITA.

I never worried about that, because a lot of places just dump it down the sewer. So that's what I do, and have been doing for the last 50+ years. And from what I've heard from a lot of people, that's not the environmental disaster a lot of people like to make it out to be.