How long is conventional green good for....

[Ramblin Fever]

currently have only 11k miles and 2yrs exactly on a radiator replacement that came along with a coolant flush.

Truck has 199k miles, regularly serviced every 3yrs with fresh coolant, but that's when we were averaging 15k miles EVERY year, not every 2yrs.

 

[c3po]

2 years or 24,000 miles.

 

[eljefino]

you want to change it. "Fresh metal" gets coated with silicates which have already been removed from the AF that's in there, which is now thin on additives.

From here on though if you want to neglect it and do every 3 years, that's what I'd do.

 

[Kuato]

I've always drained and refilled my radiator every 18-20 months, and except for a couple of water pumps here and there have never had a cooling system problem.

 

[Food Scientist]

I have used green antifreeze for years at a time until it turned brown or sprung a leak. Never had any cooling problems even with 200k + miles.

 

[SLCraig]

Originally Posted By: c3po
2 years or 24,000 miles.


Is that some sort of published figure? Just wondering, not disputing or anything, but most people go much, much farther than that and only end up putting in new coolant when something in the cooling system gets replaced. My dad is good with general maintenance, but always leaves his cooling system alone. We recently did the water pump on that car and of course it got treated to all new coolant at the time. I would guess the coolant had at least 60,000 on it. (green)

 

[Kestas]

A Ford coolant engineer once showed me data on coolant effectiveness some 15 years ago. This is when they were comparing conventional green to OAT coolants. I can't remember exactly what coolant parameter was plotted, but conventional green coolants dropped in value and crossed the threshhold at exactly 30K. The OATs flat-lined, and never lost their efficacy for 150K. I can't comment on time - these were accelerated tests.

 

[doitmyself]

I think that the 2 year/30,000 miles change interval reflects the old, high silicate green formulas. Today's green coolant silicate level is about the same as G05's (at least Zerex is).

Zerex recommends 5 years/100,000 miles on their green coolant.

I did my daughter's Escort at 3 years, 60K and everything "looked" fine. 2 to 3 years, 50K +/- should be fine, based on my anecdotal evidence.

http://www.valvoline.com/pdf/zerexoriginal.pdf

 

[mechanicx]

I agree. The tests that I have read show green starts to become depleted at 2y/30k miles. And this is the interval recommended for adding suplements for HDs using green. You can push that limit some especially on the factory fill where everything is perfect, but somewhere around 3 to 4 years you often would start seeing signs of corrosion especially if you removed the thermostat.

I'd say the high silicate formula would have a little longer service life than the low silicate formula since the silicates are one of the first inhibitors to deplete. There is high silicate and low silicate green but it's all low silicate now. GM had a high silicate spec and this was probably to give better protection for the aluminum parts that was being used more. I think that some of the low silicate green and to a lesser extent G-05 on the market being advertised as 5y/100-150K is more marketing than an engineering rating. Although G-05 has the OAT benzoate and a few other different inhibitors from green so it can have a longer life.

 

[Ramblin Fever]

So...is the timeframe solely based on years, not mileage?

I only have 11k miles on this antifreeze and exactly 2yrs. Stuff looks as clean as it did the day I put it in.

 

[mjoekingz28]

Alot of owner manuals stated 30k. 30k is a good all-around number for alot of other things too (air filter, transmission fluid, etc).


Ramblin Fever, its 2-3 years OR 30k miles, which ever comes first. It should stay clean, if you neglect it too long then you'll then be doing a flush instead of a drain and fill.

 

[electrolover]

id still flush it. a flush every couple years is a good idea in my opinion. but at least drain and fill. 3yrs max i would think.
but you can always go by the car manual and the claims of the fluid your using.

example
my truck says change at 100k then every 50k after
my coolant says it good for 100k
i go by the less of the two

 

[Kestas]

Originally Posted By: Ramblin Fever
Stuff looks as clean as it did the day I put it in.

When it looks dirty, you've waited too long. Are you suggesting to leave it in until the coolant degrades and damages the cooling system?

 

[Ramblin Fever]

Originally Posted By: Kestas
Originally Posted By: Ramblin Fever
Stuff looks as clean as it did the day I put it in.

When it looks dirty, you've waited too long. Are you suggesting to leave it in until the coolant degrades and damages the cooling system?


Heck no..that's not what I'm suggesting at all.

Just asking if 11k miles is reasonable; I've heard of people who store their cars or only drive them 5k miles a year, which is what I do, and never change their AF in 2yrs time.

The entire cooling system on this truck was replaced 2yrs ago, including 14 new coolant hoses, tiny and big, upgraded radiator, and had 2 coolant flushes performed during the process.

I'm only asking cause I have no way to personally change it, I no longer have a garage and we live in a dusty area that's pretty cold this time of year....so I'll have to pay the shop to do it, just didn't know if I should put money towards getting that done, i.e. imperative right now, or if I could spend a few dollars on the kids for christmas.

Money is non-existent and unemployment income is running out since they have not approved of the extension that BO has already allowed.

I can't afford to be replacing any further cooling system parts, so the truck will have an appt next month.

Thanks for the responses I do appreciate them...personally though, I'd like to say that I don't believe in the 50-100k mile AF types, even from factory.

My tacoma came with AF claiming 5yrs or so many miles; it looked far worse off at 15k miles and 2.5yrs then the green stuff does.

 

[mechanicx]

I think it is a factor of both time and milage but milage is probably the bigger factor usually. You could probably push the 2 year interval a year or two to 3 or maybe 4 years if the milage is low and not see much permanent harm done. Green really only has a shelf life of 3-4 years typically. Like Kestas said you don't want to wait until the coolant is obviously going bad, but keeping an eye on it will at least tell you when you are going too far. The idea is to not run it way over 30k miles or much over 2-3 years even if the milage is below 30K.

The manufacturer rated 5y/100-150k coolants are conservative and they are capable of doing it. I'm not sure what vehicle you have but it may be possible to do a complete switch next time to at least G-05 and get up to a 5 year change interval.

 

[doitmyself]

So, Kestas and Mechanicx, am I wrong in thinking that today's conventional low silicate product such as Zerex green is much better than the old high silicate conventional?

Why else would they recommend it for up to 5 years, 100K miles (not that I would use it that long)?

 

[mechanicx]

I'm not sure why Zerex advertises 5 years/100k miles for their original green. As far as I know they are the only one making the claim. Maybe they made some tweaks (maybe boosted the phosphate level or made the alkalinity last longer) to their formula but lowering the silicate level wouldn't increase the service life that I can see. I tend to look at as more marketing than actually better performance.

I wouldn't say you are wrong that low silicate green is better than high silicate for service fill. For factory fill a high silicate formula made sense because it was laying down a corrosion barrier on a new cooling system, but high silicate coolant could cause more potential problems for service fill.