Antifreeze lifespan

[Cadman-iac]

  I know this has been asked before but I didn't find it in my search.
 I think I need to flush and refill my daily driver,and I keep thinking that the recommended change interval for antifreeze is 3 years. Is this correct, or can it go longer?

 Rick

[TJ Hopland]

How old is your daily driver?  If its in the last 20 years I would hit up the owners manual and use and do what it says.

Older than 20 years?  Thats a little more difficult. What sort of miles are you putting on?   

[Cadman-iac]

  I had to go out and look through the logbook for the information on when I last changed it.
To start, it's an 88 burb with the 350, now has 185k on it. I changed everything at 150k, which was in April of 2017, so 7 years and 35k miles on the antifreeze now.
I've heard 3,4,and 7 years for intervals. I'm surprised it's been that long since I did it.
I'm going to change it for sure. But I'm still curious as to what the recommendation is.

Rick

Edit:  by everything,  I mean radiator, water pump, hoses, stat, and belts.

[Chris McBride]

I don't know but here's s link which claims 2 years/30000 miles for your application. Seems like a pretty short interval by contemporary standards but "(I) saw it on the internet so it must be true!"

'Draining and refilling with fresh coolant should be done every 30,000 miles or 24 months, whichever comes first.'

https://haynes.com/en-us/tips-tutorials/1988-98-chevy-and-gmc-ck-150025003500-pickup-trucks-blazer-tahoe-suburban-and-yukon-0

hth

Chris

[Cadman-iac]

 Yeah, I think I exceeded that interval just a little bit.
 Time goes by so fast anymore.
 Thanks for the information. Got work to do now.

 Rick
 
 

[Mike Josephic CLC #3877]

There are test strips that are available that you can
purchase from various sources (Amazon) that will tell you
if your antifreeze is still good.  Most garages will not
typically drain and refill based on the old recommendations
of 2 years/24,000 miles since dumping this down the sewer is illegal now.  I suggest you look into this unless you live
in an area that you have other disposal options.

I used to (back in the day) change my antifreeze every 2-3
years however with today's formulations that's overkill -- especially with our low milage driven cars.

Mike
 

[Cadman-iac]

  Thanks Mike,
I have a couple of options available for getting rid of the old antifreeze. There's a county run site within 6 miles from me,and the local Napa store also has a tank where you can drop it off.

I use the green stuff still in all my vehicles, as I don't believe the dexcool stuff is as good as it's claimed to be.
I've been using a 70/30 mix to get the maximum temp protection per the chart on the container as I'm in southern Arizona.
I have a tester that indicates the protection level, however it does not tell you the PH level.
Today I just happened to notice that the overflow tank was over-full and the color was a bit brown.
The over-full condition was due to the cap, which I've already replaced. But it made me think about how long antifreeze is good for.

I know this isn't a Cadillac, but the issue applies to all vehicles, and I appreciate the feedback. I knew this stuff, but like the time, my memory also seems to be going faster with age. One reason why I keep a logbook for each vehicle, it doesn't forget, unless I do and don't write it down, there's too many things to try to remember what I've done and when and to which one.

Rick

[James Landi]

It's an excellent question... The green stuff can become acidic and that can cause the "freeze-out" plugs to rot, so Mike's suggestion regarding the litmus test strips for the coolant can easily eliminate the acid concern.  What's more concerning is the scaling that inevitably accumulates on the radiator core, and that problem will cause disastrous overheating and radiator blowouts during the summer when your a/c is blasting and the idiot light on the dash is impossible to see. Bottom line in my judgement, an accurate temperature gauge that you can monitor and locate a good radiator shop that knows how to clean radiators and engine blocks.   James

[dn010]

Dexcool works as long as you have a nice leak free system and it can provide years of problem free service. You're basically screwed when you unknowingly get even a pinhole that allows air into the system with dexcool. Months go by and your cooling system turns into a horrific mess. 

You can get away with slacking for a bit on the regular green coolant maintenance on the old cast iron blocks, it is the engines with aluminum components that will be eaten by acidic antifreeze. I would be paying more attention on coolant change intervals with aluminum.

[smokuspollutus]

That is true. Most fuel injected engines came with an aluminum intake manifold during this time. Just about all of the V8s I can think of besides the big block Cadillac had a crossover cast into the manifold. With a bi-metal setup, acidic coolant will pit the crossover area and can create an internal coolant leak which is no bueno. James has mentioned the freeze plug issue as well, which is common to all cast iron motors. It can be a big deal if you get a leaking one on an Eldorado as several are basically inaccessible without separating the engine and transmission.

An important thing we should all check is the presence and condition of the engine mounted ground strap. Without this, galvanic corrosion can really pick up speed.

[TJ Hopland]

The test strips seem like a reasonable option.

There is something in modern even green formulas that creates a sort of slime layer on copper.  An old time radiator shop was telling me about that and pointing it out several years ago. The slime doesn't seem to damage anything directly but it does reduce the flow and heat transfer efficiency.  It also doesn't just easily flush out.  At the time the shop owner didn't know of a solution.  It was just one of those changes that was made in the 90's and the copper thing didn't matter since by then copper wasn't being used.   

[Cadman-iac]

  James,
I'm fortunate that the burb has a full set of factory gages that still work great. The only thing I dislike about them is that they are electric and not mechanical. But I'm not going to try swapping them just for that.

TJ,
Who handles those test strips for the antifreeze? I'd like to get some for future use.
Yes, there's an inherent "slimyness" to the glycol coolant anyway, but I had always thought it helped with the transfer of heat since it clings to the metal, and skin.

Dan,
Yes I'm familiar with the mess dexcool makes. When the first vehicles that came with it began coming into the dealership for service I remember looking at the mud in the cooling system. I had heard horror stories about the mixing of the two coolants causing problems, but hadn't heard it could be from ai r in the system. That's interesting.
I've only got one vehicle that had it, I say had because I completely flushed it and converted it to the green coolant, marking the cap and overflow as reminders.

Smokes,
It does have an aluminum intake and radiator. The intake is factory, the radiator a replacement for the original copper one.
  The ground cable goes from battery direct to the block. There isn't any other grounding that I recall. Would an additional strap make any difference?

  Thanks everyone for your replies, I do appreciate the feedback.

Rick

Edit: Question, what if any flushing solvent/cleaner would be best to get rid of anything harmful in the system, or would just back-flushing with fresh water be sufficient? I've been leary of using anything harsh to flush the system because of possible damage by the flush agent itself.
Any recommendations?

[TJ Hopland]

I don't have a specific source or brand for test strips.  When Mike mentioned them above was the first I heard of it so I just did a quick google and it looks like they are a thing and worth a shot.  No sense going though the hassle and expenses of changing it if we can just test and see its still good.

The slime the guy showed me was more than some molecular coating, it was pretty thick.  It was years ago so I don't remember specifics but it was something they changed possibly because it was better for aluminum just happened to be not good for copper.  I didn't really take careful notes since he didn't know of a brand that didn't cause the problem.   I think he said its not bad on daily drivers but gets bad when the cars sit.   

[Cadman-iac]

 Sorry TJ, I didn't look back far enough in the thread. I saw your mention of the strips glancing back at the posts. I should have gone a bit farther and I would have seen that it was Mike Josephic.
 I have 2 other vehicles that are not finished yet but have antifreeze in them that I need to check now. I put new stuff in both years ago and left them sit thinking that they would be fine if not used.
 Hopefully I don't find a big problem with either of them. Both are SBC with aluminum intake manifolds and copper radiators. Fortunately neither has a battery in it, so no current flowing to add to the problem.
 Getting old sucks!!

[Cadman-iac]

It's no wonder why I'm confused about how long the antifreeze will last.
I found an old container from probably 7 or 8 years ago and this is what it looks like.



Then I grabbed this one off my shelf, I got it probably 2 years ago.



And here's what I picked up today.



See any difference?

And they only had 3 gallons today, said they were reformulating the product and would have it by next Friday.
So I wonder if it will be good for 20 years and 500,000 miles?

Honestly I think they just change the labels so they can justify jacking the price up.
Anyone know anything about this?

 Question, does the PH level tell you anything about what temperature, high or low, the antifreeze protects to, or just the acidity?
 I have one of those testers that draws the fluid up and the needle points to whatever your protection level is. This isn't the same thing right?

Rick

[TJ Hopland]

15+?  They just come up with that since very few people have the same car for more than 10 years?

Seems like one step away from Shimmer floor wax/desert topping. What can't it do?

[Cadman-iac]

15+?  They just come up with that since very few people have the same car for more than 10 years?

Seems like one step away from Shimmer floor wax/desert topping. What can't it do?

I guess I'm one of the few that'll keep a vehicle until the wheels fall off. I've replaced parts I bought with a lifetime warranty as far back as 1986 in some cases as I've still got the truck. But the good stuff usually lasts much longer anyway.
Yeah, it's a marketing ploy, they expect most people to trade out or sell before the warranty expires on the parts. One reason why most stuff these days is junk.
Shimmer huh? Lol!!

[Carfreak]

Shimmer huh? Lol!!

Of course SNL when they were funny.

https://www.nbc.com/saturday-night-live/video/shimmer-floor-wax/2721424

To keep relevant to the Cadillac requirement, Dan Akroyd was in the skit and his character's Eldo Brougham from Driving Miss Daisy is in the CLC Museum at Gilmore Museum.

[Cadman-iac]

Of course SNL when they were funny.

https://www.nbc.com/saturday-night-live/video/shimmer-floor-wax/2721424

To keep relevant to the Cadillac requirement, Dan Akroyd was in the skit and his character's Eldo Brougham from Driving Miss Daisy is in the CLC Museum at Gilmore Museum.

 You have to have the app to get the video to play. Not sure if it's worth loading even to watch a Cadillac. I'm leary of any apps I'm not familiar with. But thanks for the link anyway.

 Rick

[TJ Hopland]

There is no Cadillac in the bit its just the antifreeze marketing seemed similar in how amazing and universal the product is.   I want to say its Chevy, Akroyd, and Gilda? Chevy is the salesman?  New Shimmer its a floor wax and a desert topping.

Its odd that that one doesn't seem to be on youtube, I see others from the same era with the same players so I don't know why they would be holding that one back.