Antifreeze/Dexcool

[Billy_ocean04]

I went to a hole in the wall oil change place because I don't like doing my own in the winter and the guys go to fill up my resivoir with antifreeze and I stopped him and said whoa buddy!!! Dex cool only. What works better? I've seen some tahoes with antifreeze. Will antrifreeze damage anything??

 

[haks310]

Tahoe has ran green for 89K miles without problems. Believe it came from the factory like that.

If you read up on Dexcool you will see it has gained the name of Deathcool. A lot of guys blame it to contributing or even causing the famous intake gasket leak. You will hear that it eats up plastic nd gaskets over over time. And a lot of guys even do a coolant flush on brand new trucks filled with Dexcool and replace with regular antifreeze.

I think if you keep your cooling system running at its best; doing regular pressure tests and changing out the coolant when need be, you should be fine. Wheter it is retular antifreeze or Dexcool.

 

[AtomicHoe094]

couldnt of said it any better haks.

 

[cam3439]

I heard that GM found out about this problem and reformulated the dexcool around '07. If you change it within reasonable intervals then you should be fine. The problem with the different coolants is that once they start to break down they start to turn acidic. This then starts to eat everything it touches until you do a clean and drain of the old fluid. I have dexcool in my '02 Z71 Tahoe, it hasn't had one leak yet, and it now has 170k on the odometer (knocking on wood).

 

[Tahoe03mm]

the main thing is it should be phosphate free

 

[ChrisInWI]

Also I've heard that the extended life stuff (dex) has enzymes in it that help it last so long that will become instantly neutralized/dead/useless the minute they come in contact with any regular green antifreeze.

 

[mossyoakman827]

dex will defenatly cause intake gasket problems been there replaced that if it were mine id drain and flush the system and run green

 

[Billy_ocean04]

Thanks everyone for all the info. I plan on doing a flush and getting some fresh fluid in the radiator this week.

 

[haks310]

Also I've heard that the extended life stuff (dex) has enzymes in it that help it last so long that will become instantly neutralized/dead/useless the minute they come in contact with any regular green antifreeze.

Yeah, you dont want to mix this stuff unless it is stated that youn can. Mixing Dex with green will sludge up your cooling system and engine It turns into a muddy substance, not good at all.

 

[rucr8z2]

dex cool went from a really orange look to more of a pinkish look after the reform. Never had any problem with either except when green is mixed in with it. Then if left in, it turns to a crap brown and totaly gunks up all coolant passages and will never stay clean again. The reason most vortecs intake leaks is from the plastic and rubber gaskets (getting old and cracking).
Felpro gaskets has a updated rubber incased steel gasket that will never leak like the old plastic gasket...

 

[IRQVET]

Wow, I just had this conversation with my mechanic today. According to him, along with a mess of garage mechanics I know, all of them say to stay away from GM Dexcool.

My mechanic said he just this week had to replace the heater core on a 2004 GMC Yukon that he contributed to running Dexcool for 100K without a collant change because, from what the owner said, the dealership told him Dexcool is good for 100K miles.

Everyone told me to run green. (Prestone to be specific) and I have been running it ever since.

 

[99Yuk]

When I swapped in my new crate motor, the Mech insisted on going with green. He showed me two fully blocked water jacket holes in the rear of the old block which he said was caused by running orange. So now I'm green. I dunno, but I figured the old guy knew what he was talking about and went with it.

My old block is out in the garage, I'll take pics today and post after if anyone wants to see, but it's cold out.

 

[Billy_ocean04]

yeah i want to see how it looks

 

[Archer04]

Well I am doing the 100k service on my girl right now, wasn't done by previous owner. So far I have gotten the rear diff, oil pan gasket, and oil, power steering to include hydro boost and gear box. Still got to do the transmission, front diff, and transfer and of course the radiator. Think I will go green after a complete flush and clean, but the question I have is since it has to be flushed should I use a chemical flush with it, and let that run in the system for three days as instructions on it recommends, or just flush without a chemical flush? Any advice is greatly appreciated.

 

[TigerEyz3]

I'd do a chemical flush followed by a clean water flush to eliminate the possibility of gelling (what happens when DexCool interacts with "green" coolant), then fill with your desired coolant.

 

[Back N Black]

My co-worker and I were discussing the Dexcool crap earlier tonight. When looking at the two types of antifreeze, he poured each into cups, mixed them together (50/50 mix) and it gelled in minutes. I had that crap in the first car I ever bought new. I owned it until about 60-70k miles. This was before they apparently changed the formula though. I learned that it was supposed to be good for 100k miles. If this is true, why did it look clumpy and foamy in my car? Maybe it's better these days, but I still refuse to run it. The old green stuff has been used for about 100 years, if it's worked for so long, in so many vehicles, why switch to something that you already know is iffy?

After reading your post Archer, I really wished I had flushed my system. My lower intake manifold gaskets had fail for the third time, atleast. I found receipts showing that these gaskets have been replaced twice before. When I got my Tahoe, I knew it had issues and couldn't drive it. Luckily for me, the gaskets allowed the system to flush itself . . . right into my crankcase! No big deal, gave me the opportunity to rebuild my first engine! I should have flushed it after putting everything back together. Might have to do that soon, just in case.

As far as your question, the chemical treatment sounds like it could be kinda harsh on the motor. At the same time, I really don't think that plain water is going to flush the system. You really have no other option. Use the chemical flush, and then a plain water flush.