GM anti-freeze good 4 150k??

[inafogg]

hi guys, ok my 98 grand am; they(dealer)say the anti-freeze is good four 150k.
has anyone let it go for this long??i have 68k on original coolant how long should i let it go??
thanks

['97ventureowner]

Absolutely NOT!! That was a big mistake GM made when they claimed that the Dex Cool was good for 5 years or 150,000miles. As the coolant gets older there is a risk of problems including sludging up if air enters your cooling system, reduced protection for interior engine parts , and increased acidity among others. What I recommend and do myself with my vehicles that run Dex Cool is to treat it like we did the old green coolant "ethylene glycol" and that is to change out out every 2 to 3 years or 30,000 to 40,000 miles. Do a complete flush before installing new coolant.Also check your radiator cap as they get older they may start to fail and allow air to infiltrate your cooling system, causing issues.

[BNaylor]

Originally Posted by '97ventureowner

That was a big mistake GM made when they claimed that the Dex Cool was good for 5 years or 150,000miles.

I disagree. What part of 5 years or 150K miles, whichever comes first is not understood? In most cases you'll hit 5 years before 150K miles. I've made it to 5 years in my GM cars with mileage of at least 100K miles and the Dex-cool looked as good as coming out of a new bottle. Acidity and electrolysis tests were run annually and passed. Even the aftermarket extended life coolants like Prestone and Peak, etc. make the same claim now 5yrs/150K miles not just GM.

In the case of the OP the Dex-cool should have been replaced back in 2003-2004 since he has low mileage. What maintenance plan you undertake is based on personal preference and experience, therefore advice will vary. However, there is nothing wrong with increased maintenance intervals if you have the time and budget or a test fails indicating the need to do so.

['97ventureowner]

Well everybody is entitled to their own opinions and it seems you based yours on your GM cars and what you've seen.I based my post on my own experiences and what I've seen with other vehicles that have come through the shop in the past.
GM is trying to make their vehicles as "maintenance free" as possible and that can come at a price. Those that do not maintain their vehicles properly are subject to issues with their cooling system because they may misinterpret that 5/150 as having to do nothing to their cooling system when just the opposite is true.
I'm from the "school" of doing preventative maintenance which includes checking and replacing things before they go bad, thus costing more in the long run. Sure GM has the 100,000 mile spark plug, but I never let them go that far,usually replacing them around 80,000 miles max. I've seen customers leave them in beyond 100k and the problems that ensued trying to remove them among others. I've also replaced the intake gaskets on 2 of my vans and upon research it has been found that Dex Cool can contribute to the degradation of these gaskets.
For the cost of a flush and fill I think it's good insurance to change the Dex Cool coolant more frequently than was previously recommended. In fact, when it was apparent that Dex Cool was causing so much problems and there was a big public outcry, GM quietly removed stickers from the engine compartment with the 5/150 recommendation.Plus changing it more often can alert the customer to problems that might be in the early stages.
Dex Cool being an Organic Acid Technology based coolant is supposed to be better for these newer engines with a better protection package than the old standby ethylene glycol based "green coolants". But as with these improvements the protection package still break down over time, and it just makes good sense to avoid any potential issues by changing it more frequently than was once recommended. I've done a lot of research into coolants since I've replaced both IMG in my vans and seeing what other customers have gone through. It was once thought to be a good idea to replace the Dex Cool with the green coolant, but Dex Cool was specifically designed for these engines and properly maintained,(i.e. changed on a regular basis) is still the best choice. Just because it says it can go 5/150 doesn't necessarily mean it's a good idea to do so.

[taillight]

Of course you are both right. In my shop I have also seen Dex cool that was sludge in 3 years in one car and one with 12 years and the Dex cool was as clean as the day it went in. Same with the Ford yellow. Best is to check it every year and change it before it starts to go bad. Like I tell my customers "You can pay me now or you can pay me later, it just depends on how much you want to pay".

[BNaylor]

Originally Posted by taillight

Of course you are both right. In my shop I have also seen Dex cool that was sludge in 3 years in one car and one with 12 years and the Dex cool was as clean as the day it went in. Same with the Ford yellow. Best is to check it every year and change it before it starts to go bad. Like I tell my customers "You can pay me now or you can pay me later, it just depends on how much you want to pay".

Man, I almost fell out of my chair. You actually posted more than 5 words in a reply.

IMO which I am entitled to it is not a matter of who is right or wrong but many factors or variables and again personal experiences and preference. The issue of Dex-cool will be debated over and over and for years to come but I see no problems with Dex-cool. No one has been able to prove Dex-cool should not be used even up to 5 years or 150K miles, whichever comes first let alone improve on GM's recommendation which has carried over to the aftermarket coolants available at any auto parts store. All I've seen is conjecture and speculation. Lawsuits don't count since no litigant has prevailed against GM. Also, the infamous lower intake manifold gasket problems with GM 60 degree engines such as the 3100 or 3400 was not caused by Dex-cool but poor gasket design and material.

Now since it has been raised one problem I see with in "my shop advice" or "at my parts store advice" is the business aspect which is profit driven $$$ and not necessarily in the best interests of the customer or consistent with the manufacturer's recommended maintenance intervals. If you make a statement such as "You can pay me now or you can pay me later, it just depends on how much you want to pay" all I will do is walk out of the store or shop and do business elsewhere.



Here is a pic of Dex-cool drained out of an '02 Olds Alero GL2 (3400 V6 SFI engine). The acidity test and electrolysis tests passed with flying colors. No other mechanical problems. No sludge or any other contaminants. However, it was 5 years old and replaced with Prestone Extended Life coolant which is good up to 5 years or 150K miles, whichever comes first similar to Dex-cool. The car only had around 49K miles.



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