Green coolant put in place of dex cool...

[Kira]

Someone mixed green with the Dex-Cool in a GM car's system we bought. I flushed it immediately and went to genuine Dex-Cool (old Chevy mechanic bought up a bunch when his dealership was sold-then had a garage sale) and distilled water; mixed 1:1 (aka 50/50).

It was still sparkling orange when we refreshed it 6 years later.

 

[bullwinkle]

When GM went to a pressurized degas overflow tank (like Mercedes & others have had for decades), & got rid of the wet/coolant nylon LIM gaskets, the Dexcool issues disappeared. As long as air is kept out of the coolant, the rust/sludge issues are gone. That said, the early years of Dex claimed a few GM engines before GM could get their shoddy engineering fixed.

 

[DBMaster]

I had an 89 Honda Accord for 23 years (1989-2012). After replacing the factory fill I used that Sierra stuff (propylene glycol). In 1997, after hearing about this new long life Dexcool stuff I did the usual drain, fill with distilled water, drain again, and refill with Dexcool. Oh, I heard all the horror stories. Never had a bit of trouble. Cooling system parts still looked good at 350,000 miles.

 

[SteveSRT8]

Originally Posted By: bullwinkle
When GM went to a pressurized degas overflow tank (like Mercedes & others have had for decades), & got rid of the wet/coolant nylon LIM gaskets, the Dexcool issues disappeared. As long as air is kept out of the coolant, the rust/sludge issues are gone. That said, the early years of Dex claimed a few GM engines before GM could get their shoddy engineering fixed.


Note that our 3500 vans still have an open overflow tank. Plus with a huge heat exchanger for our aftermarket equipment. They always have air in the system yet no problems. IMO the air thing is also just heresay...

 

[DBMaster]

Shortly after I put Dexcool in the Honda I started hearing the tall tales about goo in the cooling system, especially if you didn't flush out every single molecule of green coolant first. I wasn't that careful - and, no goo. Everybody's an expert at spreading misinformation.

 

[George7941]

Originally Posted By: SteveSRT8
Note that our 3500 vans still have an open overflow tank. Plus with a huge heat exchanger for our aftermarket equipment. They always have air in the system yet no problems. IMO the air thing is also just heresay...


It isn't Dexcool being exposed to air that is the problem, it is metal surfaces that are being protected by Dexcool and then exposed to air because of low coolant level that leads to rust blooms and sludge. Even when the low coolant level is corrected by topping up, corrosion still goes on because OAT coolants take a long time to reestablish a protective layer. It becomes a vicious cycle and the end result is a sludged up cooling system. So while Dexcool is a fine coolant (I use it in my truck), it is less forgiving of shoddy maintenance practices than the old school green.

 

[Sayjac]

Quote:
.....So while Dexcool is a fine coolant (I use it in my truck), it is less forgiving of shoddy maintenance practices than the old school green.

It's not just shoddy maintenance that causes/caused a lowered radiator level and air exposure. Along with the notorious LIM gaskets, GM had angle neck radiator fill holes combined with non pressurized recovery tanks. That made filling the radiator to the top very difficult. Having owned a GM 3.8L vehicle I can attest to that fact. Combine all those factors with Dex and that's where the gelling issues could occur.

I'd have no problem using Dex in vehicles where spec'd now.

That said, with all the readily available reasonable priced aftermarket same as OEM type AFs, no reason for me to use Dex or universal clones where it's not spec'd.

 

[bullwinkle]

Originally Posted By: SteveSRT8
Originally Posted By: bullwinkle
When GM went to a pressurized degas overflow tank (like Mercedes & others have had for decades), & got rid of the wet/coolant nylon LIM gaskets, the Dexcool issues disappeared. As long as air is kept out of the coolant, the rust/sludge issues are gone. That said, the early years of Dex claimed a few GM engines before GM could get their shoddy engineering fixed.


Note that our 3500 vans still have an open overflow tank. Plus with a huge heat exchanger for our aftermarket equipment. They always have air in the system yet no problems. IMO the air thing is also just heresay...
You guys must have been living right, at least half the 350 Vortec GMC Savana vans we had (2000-2002) had Dex leaks of some kind, mainly LIM gaskets, by 125K. My mechanic actually lost a 4.3 in his parts runner S-10 on a 3 mile trip, dumped all the Dex into the crankcase & spun a rod bearing with ZERO warning.