Dex-Cool or extended life coolant question
 

I've got the cooling system drained on my '72 Esprit and there was evidence of old, acidy coolant having been in there too long. This got me thinking about any possible advantages to switching to an extended life coolant like Dex-Cool or any of the other aftermarket compatible types. What do you guys think?

I use it with distilled water and water wetter. Since I have aluminum heads and radiator figure it can't hurt

I put this in my Ducati when new a couple years ago and couldn't believe how freakin amazing it was. I use it now in my 92 GTA and will be in my 69 Firebird. It's pricey but it's the real deal:

https://www.motul.com/gb/en/products...%5Brange%5D=21

I use nothing but Dexcool, it's kind to aluminum parts...

Not sure about the newer "redesigned" dexcool but the older stuff ate aluminum and gaskets like crazy..

I don't know that I agree with that. The reason for Dex-Cool in the first place was because of aluminum radiators in GM cars.

Dex-cool has widely reported issues with older gaskets. I started using extended life 15 years ago, no issues.

I've replaced numerous head and intake gaskets on late 90's and 2000's GM vehicles thanks to Dexcool. Many of the vehicles had the coolant replaced well before GM's recommended 5 years/150,000 miles. It eats gaskets like its candy.

Oddly enough, I did have it in a '78 Scout for 6-7 years and didn't "seem" to have a prob...Although very few miles those years, maybe 4K.

That is what I always heard and talking to an engine rebuilder, he didn't like that stuff either. I've got a '97 Lumina I changed intake gaskets on and flushed it with water and then refilled with good old green antifreeze.

That's why they came up with it but it didn't work out so well. Lot of problems with it when it 1st came out and some miles got put on cars.

I have no reason to defend Dex-Cool but my own view was that Dex-Cool came about at the same time GM was using a poorly designed intake gasket.

AFAIK, the problems went away when the intake gaskets were redesigned.

I had such a failure in my first vehicle with Dex-Cool, '97 GMC Safari van that I bought new and kept for 13 years.

I ignored the problem for years, just kept adding Dex-Cool when needed. Finally got the intake gasket replaced when I saw coolant in the oil pan.

Can't be sure, but a few years later that 4.3 V6 spun multiple rod and main bearings at 170K miles and I believe that failure was caused because I ignored the internal coolant leak for so many years. Intake gaskets were replaced with the "new and improved" version and never lost coolant again until the bearing failure.

I have Dex-Cool in my '04 GP GTP, supercharged 3.8, also owned since new Oct '03. It got changed after 5 years and again after 11-3/4 years.

Have never had to refill coolant in between those change intervals.

Still has original water pump, radiator, and radiator hoses. I replaced the T-Stat some years ago. Has 130k miles now.

I guess the question is, was the original intake gasket material incompatible with Dex-Cool or was the material and gasket design poorly selected regardless of the coolant they might have used.

Still, I don't think I would use Dex-Cool in any older engine. If you are running a copper core radiator and/or heater core, I would stick with the traditional coolant.

Some useful info here.

https://blog.hemmings.com/index.php/...of-antifreeze/

Great article there John. Thanks guys for the input. Leaning towards just sticking with basic old green coolant.

Agree, its the plastic gaskets with rubber seals along with small headed bolts(less clamp load) that fail.
Fel Pro was the 1st to offer better metal gaskets w/rubber seals.

Yes, those gaskets were a terrible design and failed left and right. Head gaskets also had a problem with failures due to erosion around the coolant ports.
I saw several cars where dexcool had eroded the aluminum so bad, intakes and heads had to be replaced along with pinholes in the rads and heater cores. Nasty problem.
Seems that the redesigned stuff is better theses days tho.

Do they even MAKE the 'old green stuff' anymore? I thought it was all a newer blend that works across the board? For the most part. I think I heard that in like 2012 or 2014 they came out with another blend, that is made for certain alloys, but it too is supposed to be backward compatible?

.

My brother in law work for a heavy equipment operator where they would order premixed by the barrel full, many of them. So he would get me several gallons of it when I needed. I think I still have 2-1/2 gallons stored.

We use the old green stuff at work. We get it in 55gallon drums

Bought my wife a 20,000 mile '97 Cadillac Sedan Deville D'elegance back in 2000. It done everything but wipe your butt. Babied that car. It had the north star. It blew the passenger side head gasket at 70,000 miles. Dealer wanted $6,000.00 to fix it. Got a friend of mine that owns a German made only garage to repair it for $1800.00. Dumped that Cadillac quick as I could for a supercharged Buick Ultra. After reading about Dex-Cool antifreeze here, I wonder if that was the problem?