15 year old dex cool

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So I decided to drain and refill coolant in 2001 tahoe we have had since around 2002. I thought I had changed this several years back but I don't have any record of it and I keep good records. Never had water pump,coolant leak, or anything for that matter.knock on wood. Only thing different under hood is couple new batteries and couple air filters over the years.. well coolant came out very clean, color looked great,not rusty or discolored. There was little sediment in resorvoir which I took off and cleaned out. Also just little sediment in drain pan but not much. I filled with 50/50 mix of super tech amam. That's all I had in shop handy so that's what it got. I will do another drain and fill soon and call in good. But any how I'm really impressed with this dexcool considering how long it's been in there and really feel I could have just left it.
 
I checked the dex cool in my 04 Cavalier, which has yet to have anything major fluid changed (coolant, trans) since new due to the low mileage the car has. I have even got to check everything in heavy traffic, and things look good.

That said, all fluids will still be changed, just to be safe. Never sure how long it will hold up in the long run when it is that old...
 
The "Death-Cool" moniker for GM vehicles in the past was because of an INTAKE MANIFOLD GASKET ISSUE, not a coolant issue.
 
The Dex cool in my Malibu is 9 years old and seems to be holding up very well. I also have a 99 Caravan with the original coolant in it. Some things about automobiles have definitely improved. I think aluminum radiators have helped.
 
Originally Posted By: DemoFly
The "Death-Cool" moniker for GM vehicles in the past was because of an INTAKE MANIFOLD GASKET ISSUE, not a coolant issue.


Let's call it what it really was. It was not just an intake gasket issue. It was the fact that plastic intake gaskets and Dexcool were not compatible. Dexcool contains the ingredient 2eha which is a known plasticizer.

Just setting the record straight since I was directly effected by the issue, but did not sign up for the class action Dexcool lawsuit because I knew it would be a slap in the face. I am betting that there were thousands of others like me that did not sign up. The lawsuit was settled by GM, so that's that.
 
Originally Posted By: oilpsi2high
FYI, Dex becomes acidic over time and it's impossible to tell by looking at the color.


Generalize much?

Given enough time all coolants will become acidic. Dex is a very capable long life coolant- just ask member SteveSRT8. He runs a fleet of GM vans and will leave the Dex in until the engine has some form of a cooling system malfunction. This can be upwards of 250k miles or more! Even then, the coolant isn't "sludgy" and the cooling system is clean.
 
I won't use Dexcool in anything that never came with it, but I use the same practice as Steve for service on our GM equipment that came with Dexcool, and never have had an issue.

I was told by a very good GM tech to never do anything but top off the coolant unless the system required mechanical service, and that has proven to be sound advice.
 
Dex is to be drain & refilled every 5 years/100,000 miles, whichever comes first. If you go 10 years then consider yourself lucky, as it's well past it's usable life.
 
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Originally Posted By: oilpsi2high
Dex is to be drain & refilled every 5 years/100,000 miles, whichever comes first. If you go 10 years then consider yourself lucky, as it's well past it's usable life.


Not really, if its not dirty its just fine,
 
By the time you can see the dirt it is too late.

How difficult is it? Dexron spent who knows how much time and effort to (apparently) make a coolant since 2yrs/24,000 miles apparently wasn't doable for us. Now, we cant even keep to a 5yr/100-150,000 mile interval?


Who is this Dexron? I liked the old green coolant. Too bad it seems to be disappearing.
 
Originally Posted By: oilpsi2high
Dex is to be drain & refilled every 5 years/100,000 miles, whichever comes first. If you go 10 years then consider yourself lucky, as it's well past it's usable life.


Dexcool is 5 year/150,000 mile.
but to agree I guess I'm lucky it didn't come out looking aweful. But it didn't. I'm not saying to go this long on any coolant but if u think about extended drain coolants, as long as nothing is leaking and it never gets low it really should be no problems as the protection don't fall out like with older conventional coolant. I do understand other things can happen.The only reason this stayed in that long is that I goofed up. I maintain several tractors,lawn mowers,five automobiles, two polaris rangers, two four wheelers and also other family members stuff. And nothing ever goes to a shop. I just like maintaining stuff. If i buy something i want to know how to maintain it and whats in it.I just missed this somehow and when i looked back over my service records i coukd not believe i couldn't find where the coolant was drained and filled a few times. That's why I'm here. This site and it's members have taught me a lot stuff over the years..
 
Originally Posted By: Bluestream
Originally Posted By: oilpsi2high
Dex is to be drain & refilled every 5 years/100,000 miles, whichever comes first. If you go 10 years then consider yourself lucky, as it's well past it's usable life.


Not really, if its not dirty its just fine,


Incredibly false.
 
Originally Posted By: oilpsi2high
Originally Posted By: Bluestream
Originally Posted By: oilpsi2high
Dex is to be drain & refilled every 5 years/100,000 miles, whichever comes first. If you go 10 years then consider yourself lucky, as it's well past it's usable life.


Not really, if its not dirty its just fine,


Incredibly false.


When I was on vacation a few years ago, I met a guy who was a coolant chemist for a major oil company. We spent a lot of time socializing with him and his wife. He told me coolant changes every two years are the most over sold maintenance product in automotive. I asked when to change, and he told me when its dirty. That advice has never done me wrong, and I will take it over advice from hacks on the internet.

My 91 BMW has had 2 coolant changes in 25 years and the rad is like new inside as is the thermostat housing
 
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I put DexCool in my 350 crate engine when I installed it, with a new radiator, back in 2007 or so. I finally did a drain-and-fill in 2013 - a year overdue - and I was amazed by how good the aluminum radiator looked inside. Looking into the tank from the cap, there was no hint of the scale I used to see around the tubes on old radiators. The coolant in the overflow bottle always looks perfectly clean, and I add a tiny bit once a year to replace what slowly evaporates. I've been extremely pleased with how DexCool protects and endures compared to the old green stuff, and I don't miss the annual drain, flush and fill.
 
Having experience dexcool turn into dexmud myself in a low mileage 2004 car, with no outward signs of anything being awry until removing the alternator bracket, I would be inclined to change it more often rather than later. Everything in the radiator, including the coolant itself looked brand new.

My findings led me down a rabbit hole of replacement parts and future worries.
 
Just as The_Eric and DW above noted, we never touch the coolant until something fails. This is frequently the life of the truck these days, it has been a LONG time since we have serviced a water pump or a thermostat, even busted hoses are getting rare.

Our 3500 vans are un-pressurized coolant tanks, the Silverados are all under pressure. Doesn't seem to make any difference. And the systems are always sparkling clean.

The whole Dexcool thing is long ago over and gone, folks...
 
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Originally Posted By: oilpsi2high
Dex is to be drain & refilled every 5 years/100,000 miles, whichever comes first. If you go 10 years then consider yourself lucky, as it's well past it's usable life.


How do you know? Have you done coolant analysis? How do you know that GM wasn't just being conservative with their recommendations?

I'm pretty sure I remember SteveSRT8 saying that he had a chat with a GM engineer (arranged through his work van up-fitter) who stated that DexCool was much more capable than people think. If I remember correctly, he was told that Dex's protection doesn't drop off like a rock at 5 years (as green's protection tends to). Instead it was still something obscenely high like 80-90% "effective". Hopefully he can chime in to fill us in.
 
Two days ago my car started to run a little warmer than it should so I bought a new thermostat and a jug of Delco DexCool. Job went well and the car stays at the correct temp now.

I looked inside the thermostat housing and inside the rad when I removed the lower rad hose. Everything I saw was like new. I am sold on Dexcool. 9 1/2 years on the original fluid.
 
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