As stated above, Dexcool can cause a host of problems. At our shop, we use Zerex G-05 whenever a long-life coolant is recommended. If a car originally had green, we use that. We have had no problems due to the HOAT G-05. We've flushed quite a few to get rid of the Dexcool. We even found out our local Chevy house gets rid of the stuff from customer's cars after the warranty period expires.

My mother-in-laws car plugged up two heater cores by using Dexcool in her '96 Caprice. We even installed a spin-on coolant filter to remedy it. No dice. She drives a Lincoln Town Car, now.

Mark

Dang it...

I was just given 8 gallons of Dex-Cool by a friend moving out of town.. glad I checked here before using it.. Seems like the crap is useless to me.

Moral Question:
Shall I just give it all to a GM friend and let them suffer the consequences?

- Art

That depends , is it a GOOD friend ...

hm... .. can *any* GM owner really be a "good" friend?

When Dexcool first came out it was a disaster. We routinely flushed it out and went back to green. And yes, it looked like mud.

That said, I have not had issues for probably 10 years at least. More like 15+
Coolant drained from a car newer than 2010 looks brand new at any age or mileage.

We have a drum of "Global" coolant for most vehicles and I've been switching my antique cars over to it. So far I've been extremely happy. No rust or corrosion. Costs me 1.40 per qt

I do keep several jugs of coolant for VW and some Asian cars so the coolant keeps the same color as new. I am of the opinion all new extended life coolant is the same other than the dye but on a customers car better safe than sorry. And I don't want someone noticing a different color in the overflow.

I don't think any name brand anti-freeze will be a problem as long as it is changed on a regular basis. The big issue with some of these "new" anti-freeze solutions has been the fact that people don't flush the system. Also, some of them were really sensitive to small combustion leaks. If someone gave me a bunch of anti-freeze I'd use it, but I'd also keep an eye on it. And most likely I'd change it every year or at most every 24 months.

I'll be the outlier here. Back in mid '90s when I did my 383 over I went with the cool new high tech long lasting Dexcool for my new engine. I really liked the 100k or 10 year life it was supposed to have. Flash forward to 2015 I was no where near the 100k but I was well past my due date so I changed it again. The fluid looked great. It never over heated on me and always ran cool. My second go around with it has been just as good so far. That car may be the exception to the rule, and like I say it was put in a fresh engine. On the flip side I've had more than one GM I've switched away from it because it crudded up and what not.

Dex cool is a very good coolant with regular maintenance, granted you have no presence of combustible gasses or an constant introduction of oxygen into the cooling system. Yes, I've seen the mud. And every time, it was due to failed components, not just the coolant itself. Mopar acid tech coolant is not dex cool, but they look identical.

Yet advertised as extended use coolant.

Just say no to deathcool. I dealt with two 3.8 gm cars in the family and it was nothing but trouble, even with flushes. Plugged up radiator cores like a pack of gummy bears was dropped in the tank. Saw the junk come directly out of one core and it stayed clear for about a winter before it plugged again. I believe the trans failed in one car from it running warm. Despite flushing throughly. Another northstar in the family failed like it was designed to before the plugging got bad enough to leave you cold in January.

No chance I’d run that bs in anything.

from antifreeze wiki

Organic acid technology[edit]
Most modern cars are built with organic acid technology (OAT) antifreeze (e.g., DEX-COOL[23]), or with a hybrid organic acid technology (HOAT) formulation (e.g., Zerex G-05),[24] both of which are claimed to have an extended service life of five years or 240,000 km (150,000 mi).

DEX-COOL specifically has caused controversy. Litigation has linked it with intake manifold gasket failures in General Motors' (GM's) 3.1L and 3.4L engines, and with other failures in 3.8L and 4.3L engines. One of the anti-corrosion components presented as sodium or potassium 2-ethylhexanoate and ethylhexanoic acid is incompatible with nylon 6,6 and silicone rubber, and is a known plasticizer. Class action lawsuits were registered in several states of the US, and in Canada,[25] to address some of these claims. The first of these to reach a decision was in Missouri, where a settlement was announced early in December 2007.[26] Late in March 2008, GM agreed to compensate complainants in the remaining 49 states.[27] GM (Motors Liquidation Company) filed for bankruptcy in 2009, which tied up the outstanding claims until a court determines who gets paid.[28]

According to the DEX-COOL manufacturer, "mixing a 'green' [non-OAT] coolant with DEX-COOL reduces the batch's change interval to 2 years or 30,000 miles, but will otherwise cause no damage to the engine".[29] DEX-COOL antifreeze uses two inhibitors: sebacate and 2-EHA (2-ethylhexanoic acid), the latter which works well with the hard water found in the United States, but is a plasticizer that can cause gaskets to leak.[21]

According to internal GM documents,[29] the ultimate culprit appears to be operating vehicles for long periods of time with low coolant levels. The low coolant is caused by pressure caps that fail in the open position. (The new caps and recovery bottles were introduced at the same time as DEX-COOL). This exposes hot engine components to air and vapors, causing corrosion and contamination of the coolant with iron oxide particles, which in turn can aggravate the pressure cap problem as contamination holds the caps open permanently.[29]

I worked as a line tech at a Chevrolet dealer. We used to call it Dex-Plug. The stuff clogged of heater cores, radiators. I could change 3.4 intakes gaskets with my eyes closed. we could get it free, nope.
Doug

Unless they changed it it is the worst crap ever made.Cant say how many car we had here that it sludged up in.Havent worked on GMs that used it in like 10 years.Just buy the regular coolant that can be used in anything.