mixalive

I have a 92 LT1 and it currently has the green (propylene glycol) antifreeze in the cooling system. I am in the middle of a water pump replacement and am soliciting opinions on whether I should flush and switch to Dex-cool (ethylene glycol).

WW7

If your going to switch to Dexcool your going to have to remove all the old green stuff from the system, and I mean "ALL"....If you don't you could have a problem with the Dexcool turning to gel..This is one reason alot of folks don't like Dexcool...Personally, if it was me, I would just replace with the Green coolant and save the trouble associated with switching...The Green stuff is fine for steel and aluminum and won't cause problems... "Peak Green" is what I use in my 89....But it's your call.....WW

mixalive

I like your opinion, WW and would like to stay with the green stuff. Thanks..

UNCLEBILL

Bill

Drew

I believe that Dex Cool was a factory fill on 1996 Corvettes....I would stick with the Green Stuff....

higgyburners

stay green....

70ZZ3 96LT4

Newer anti-freeze on the market is ZEREX G-05. I recently switched to it in my 1985 and 1968 Corvettes. The 1970 will be next. My 96 LT4 has always had DEX-COOL coolant changes since it left the factory 18 years ago. I am considering switching to ZEREX G-05 next coolant change.

jsdomino

Anti-freeze has changed a lot in the last few years, You will be hard pressed to find the green stuff anymore except for off brands. Almost all manufacturers have switched to the yellow (looks like urine) that they are calling "universal". 95 and earlier C4s require spec 1825M which is NOT Dexcool formula.

Check the manufacturer's website for the brand you are considering to assure it meets 1825M spec. I just flushed my system and used the Prestone Long Life Universal which meets the spec. They also claim it will mix with Dexcool, but it does not matter to me if it does, because I have never used Dexcool in my 95.

93Rubie

Peak Green Conventional Here. As long as they make it, that is what I will use.

Tom400CFI

I recommend that you read this...then decide for yourself. http://forums.corvetteforum.com/c4-t...d-results.html

"Green" will produce the same results...if you change it once every two year.

Cliff Harris

When Dexcool first came on the market I switched because it promised longer change intervals. At the time they were claiming "compatible with all systems", so I just poured it in. A little later I had a mess. I tried multiple brands of cooling system flushes and NOTHING fixed it.

I finally resolved the mess by removing the block plugs, draining out everything and then I did multiple fills with plain water, running the car, and draining until the water was completely clear. Then I drained and refilled with 50/50 antifreeze/water. I have not had any problems since and the coolant is still green.

I buy the AutoZone green antifreeze. The markings on the container are green so you know what you're getting.

RossyHusker

Two weeks ago I did a complete flush on my '90 and went with green. I almost went with the universal (had even bought it already and had to return), After reading all the posts here on CF I thought it was best to stay with what was in it from GM. No regrets here.

captboatwrench

Mixing Dex cool or extended service coolant with the old type green coolant will not cause the coolant to gel it just effects the service intervals from extended life to standard service life.The factory service manuals for the products that I work on for a living state this in their maintenance sections. I have had to top off cooling systems on marine engines with what was available at times and my customers never had problems. The 5.7L GM based marine engines can run at 5200 rpms WOT for hours and never get above 180 degrees with coolants mixed.
If you switched from regular coolant to dex cool and had problems then u were going to have a cooling system problem any way do to sludge build up from lack of maintenance.
Coolants have inhibitors that are designed to prevent corrosion and when you service a system that has not been maintained properly and may have had some type of additive put in them then the new coolant does its job and breaks the stuff up and now its moving around the system and clogs up those tiny passages in the radiator. Seen it!
When I pulled the old radiator out of my 92 lt1 with 80k miles and back flushed it with a hose and all of this whitish sludge started coming out I decided to just replace the radiator. I also flushed the blocks cooling jackets with the drain plugs out and was getting the same sludge out of it as well. I saved some of the sludge and let it dry out some and it looked like that white powdery corrosion that you see on aluminum.
I believe that the cooling system on my car had never ever been serviced.
My suggestion is that if your going to upgrade your coolant on an older high mileage performance car such as the ones we love to play with then give it a good thorough flushing multiple times with fresh water.

WW7

I did a quick search and went to the Valvoline website, If we believe what they are telling us ,then the mixing of certain other antifreeze products with Dexcool can also cause corrosion of the metels in the engine..Besides the Valvoline website here is another Automotive site stating the same thing...There are many other Manufactors websites that agree.......
http://autos.aol.com/article/coolant-color/

What they ( the industry) believe is happening is people are mixing other coolants with the Dexcool, which reduces the life of the Dexcool significantly. Then the people are leaving the Dexcool in there engines for the extended periods of time just like it was intended. But ,with the Dexcools lifespan greatly reduced by mixing the other coolant with it , it then turns to a gel/sludge causing engine problems..This is actually what part of the Lawsuit is based on...WW
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93Rubie

THIS, simple enough to do. No thought required. Its cheap maintenance.

Tom400CFI

Agreed. It is simple...it is cheap. Problem is...people don't do it.

Then we get threads about cooling issues and leaking heater cores.

mixalive

Wow..
Turned out to be a good thread..

BTW.. I went with green.

0Willcox Corvette

If I might add one thing to this... Never use tap water to dilute your anti-freeze! Use distilled water only. Your radiator will love you!

IMHO,

Willcox

корвет

Bought my 1995 new March 1996. Had the green. The 96's had the orange. In 1999 (40K) my first coolant change was due (a little over). I first flushed the whole system with the Prestone water hose kit, got it all clear. Then I removed both knock sensors to drain the block. I added 2 gallons of the Orange manually mixed with two gallons of distilled water. I have great tasting; however, very hard lime well water, it never goes in! My home hot water heater is over 50% full of lime now. Bottom element is useless!

I did the change so I could go every five years..... well.... In 2011 (12 years later and 200K total (160,000 miles) I started having over heating problems. I remembered the old coolant! But it was OK! burnt orange color now! The external fins were clogged. I flushed the system with the Prestone kit, removed the radiator, cleaned it externally and internally. I was only able to remove one of the knock sensors, gave up on the other one after 2-3 hours attempting removal. I put the radiator back in along with new orange and distilled water.

In 2012 my water pump failed. Replaced that and topped off with 50/50 orange mixture. The car now has 255,000 miles. Other than the water pump, nothing else coolant wise has been replaced! Not a single hose, heater core or radiator. I can't believe it. My 1986 Z28 was a great car that went 336,000 miles before the trans went out (5.0 was still fine - no rebuilds at all) However I think I replaced 3 heater cores, 3 water pumps, 3-4 radiator side tanks, then finally the whole radiator. And hose after hose after hose, usually yearly.

I love my Dex-Cool.

dizwiz24

I vote against the dex cool.

I had that crap in my 93 when i bought it used in 2000. I promptly flushed it out (local news was running lawsuit stories about it)

I run a 40/60 mixture of water/antifreeze with water wetter.

I have 160 tsat and reprogrammed fans. Car never sees over 175 f coolant temp.

Car used to run at 215+ f before those mods which isnt conducive to avoiding detonation on a boosted motor like mine.

So much less issues (ex. No more shrunken, cracked optispark seals like on my original opti) running cooler now than i did before.

I also run a 160 tstat