need help chooseing right antifreeze

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Jun 13, 2007
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az
ok,there's so much info here i'm going into overload.my car is a 68 gto,400 with aluminum heads/intake with a 4 core non aluminum radiator.just rebuilt.used regular green antifreeze prior to rebuilding and i had some electrolisys(forgive my spelling)it seemed to affect the intake more than the heads.now theres the universal green antifreeze,G-05 and so fourth.what should i go with the universal green or the G-05 or something else?i live in phx,az.it's my weekend cruzer.any input is greatly appreciated!! thanks,
 
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ON, Canada eh?
Stick with the good old green-glycol that is Aluminum safe. Your electrolysis is most likely caused by poor ground. Make sure your engine is grounded to the body using a good thick wire, and also from the body to the battery using the same kind of wire. This will protect your cooling system and stop the electrolysis. My engine is all aluminum and so is the radiator and I have had no problems with regular green glycol based anti-freeze. More information here: Click Here Nice car BTW... Can we see a picture of it?
 
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May 10, 2005
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Toronto, Canada
I would go with either regular green or G-05, whichever one is easily available. Some feel that OAT coolants (and, by extension, HOAT since HOAT is part OAT) do not protect copper/brass radiators well. This would make the regular green preferable to G-05. Perhaps the electrolysis was due to the coolant being left in too long. The regular green coolant needs to be changed every two or three years.
 
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The electrolsis is from letting the coolant go too long .I agree on the use of G-O5 coolant I am helping a bud put together a real nice 67 GTO.
 

oil_dude

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Jun 13, 2007
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az
thanks for your replies.they were very helpful! yes,i'm am guilty of leaving the coolant in the engine for way to long previous to my rebuilding of the engine.i will not make the same mistake again.now that after many years i have finally finished restoreing my car and am very motivated on staying on top of the maintance.i would post a picture of my car,but i dont know how to do it on this site. thanks,jim m
 
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Jim, If you want to PM me I will send you my e-mail address. You can e-mail me the picture and I will put it up for you... Would love to see the car.
 
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Novato, CA
Gents, I am replacing my DEXCOOL with standard "green" antifreeze. It is in my wife's mini-van (Pontiac montana). Do I need to go back with straight fluid, or mix 50/50? I had straight in, but the Dex was still in some componenets so it was running warm. Is the Glychol a warmer running coolant than Dex? I hope to see the picture of yours soon. Sounds like a beauty.
 

Kestas

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oil dude, I use traditional silicated green antifreeze for my 71 Cutlass to protect the radiator and heater core, which are both soldered brass and copper. Unless you have a brass heater core, I'd recommend using G-05 coolant. The aluminum radiator, aluminum heads, and cast iron block make your car nothing different from modern vehicles as far as cooling systems go. It's the same set of materials. Archie, if you plan on replacing the DexCool with something else, you'll have to do a complete flush of the cooling system so there will be minimal mixing of the two antifreezes. A search on this Cooling Systems forum should show you a good flushing procedure. DexCool and all popular coolants are ethylene glycol, and should have virtually identical cooling characteristics. The difference among the antifreezes is in the additives. Your comment about mixing 50/50 is somewhat confusing and alarms me to the possibility that you may not know what you're doing. What are you thinking of mixing 50/50 and what do you mean by "straight fluid"?
 
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Kestas, Sorry for the confusion about the 50/50. I meant water diluted or just straight ethylene. I plan on flushing my system and thanks for the info. I assumed the Dex was of differing characteristics than other green coolants. I was loking at the blogs and found that Dex is famous for eating gasket material. I just replaced the intake manifold and waterpump gaskets due to leaks and assumed that was the issue, thus the need to change to Prestone green. I put Prestone 50/50 in my Mercury as specified and was just curious about the Pontiac when I change over since it is straight Dex in spec.
 

Kestas

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Make sure whatever you use that you end up with antifreeze mixed with water at a 50/50 ratio. Never run straight water or straight antifreeze. This will harm the system. I think you can go up to 70/30 (I forget which way, read your owners manual), but it shouldn't be necessary. I wouldn't use DexCool unless the gaskets and other organic materials are designed for it. Even when it's specified it's an iffy deal. You can't go wrong with Zerex G-05. Again, don't mix DexCool with any other type of antifreeze. Bad things can happen. I believe it would gel.
 
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Where does one still find traditional coolant? Prestone's main product is now the "All Makes, All Models" version that is probably a silicate free one similar to their Dex-Cool formula. Maybe you could find something like "Prestone Prime", but I'm not sure where that might be available. There are some generic brands out there.
 
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Napa sells basic "green" zerex. Also, GO-5 is a suitable alternative to "traditional" coolant, and should last a bit longer too. Both can be purchased at Napa.
 
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I used Chevron Supreme Antifreeze which is traditional green coolant (says on the jug "Not compatible with DexCool") for my coolant flush for my 76 Chevy truck. Seems to be working well so far. Could not find green Zerex around my area, even at Napa. Napa only had G05 or DexCool at 17 bucks/gallon...
 
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G05 is $11 bucks a gallon at my local Napa. Thats a steep price your guys are selling it for!
 
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Oct 14, 2008
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Maryland
Don't know why its that high, Zerex products are very rare around my area. I heard Pep Boys sells it, but its an hour drive to go see..
 
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