Which antifreeze/coolant do you use?

[Z Factor]

There are many to choose from, so which one do you use and why?

With this poll keep in mind that many of the brands have several different lines. For instance like GM, some brands have both Dexcool lines which are Organic Acid Technology (OAT) based, and standard ethylene glycol lines.
Since it is pretty much accepted that OAT based (Dexcool) antifreeze is not good/recommended for the LT5, all the brands will be assumed to be ethylene glycol based unless specified otherwise.
Also keep in mind that not all glycol lines have sufficient silicates or are not in fact "1825-M" compliant, which is recommended.

As always, if the brand you use is not listed, post it and I will amend the poll to include it.

:cheers:

[Dynomite]

http://i287.photobucket.com/albums/ll142/dynomite007/ZR1/ZEREXoriginal-1.jpg

I am not using this yet but am thinking of using this ;)
Actually I have not found ZEREX original formula yet :sign10:
This Poll will be as exciting as the oil Poll I am sure.

[Z Factor]

^^^ According to this chart it looks like it is one of two in the Zerex line that meet GM 1825 spec.

http://www.englefieldoil.com/PDF/Zerex_chart.pdf

[tomtom72]

I'll go take a pict later, but I get mine from the chevy dealer. It's p/n 12378560.

It's expensive for sure, but it's what came in the car from BG back in 90.:mrgreen:


I may go to the local NAPA store and see what they have on the shelf or what they can order that is an E-glycol silicate coolant 1825M spec. I have only one gallon of my GM stuff left after this yr's flush & refill.

:cheers:

[Dynomite]

I'll go take a pict later, but I get mine from the chevy dealer. It's p/n 12378560.

It's expensive for sure, but it's what came in the car from BG back in 90.:mrgreen:


I may go to the local NAPA store and see what they have on the shelf or what they can order that is an E-glycol silicate coolant 1825M spec. I have only one gallon of my GM stuff left after this yr's flush & refill.

:cheers:

Hammer suggested to me a few weeks ago NAPA house brand coolant with the 1825M rating. Trouble is, I could not find a NAPA dealer around here that has not closed up and am still looking :happy1:

[xlr8nflorida]

Hammer suggested to me a few weeks ago NAPA house brand coolant with the 1825M rating. Trouble is, I could not find a NAPA dealer around here that has not closed up and am still looking :happy1:

I got 4 jugs of this for my 2 C4's.

Question, who changes the thermostat too and what all is involved?
Don't want to screw up my thermostat housing etc.

[Dynomite]

I got 4 jugs of this for my 2 C4's.

Question, who changes the thermostat too and what all is involved?
Don't want to screw up my thermostat housing etc.


Hammer suggested this in the Leaky Radiator thread :thumbsup:
http://www.zr1.net/forum/showthread.php?t=10241&page=2
http://www.zr1.net/forum/images/icons/icon10.gif Re: Leaky Radiator
Another item that can blow radiators is if the thermostat wasn't installed correctly in the housing. Easy to check, but have the catch pan ready if you pull the thermostat (don't ask me how I know that). Make sure it's seated correctly. Hold it in flush with the housing, use the bracket (Marc's trick) or a putty knife while you tighten the lower housing bolt.

[lbszr]

^^^ According to this chart it looks like it is one of two in the Zerex line that meet GM 1825 spec.

http://www.englefieldoil.com/PDF/Zerex_chart.pdf

The local Chevy dealer carries original Zerex, but it's about a dollar cheaper at Savage auto parts. It says on the bottle it has silocates.

[95ZR1#418]

About a month ago I read a number of antifreeze threads and freaked out! Last year I had installed all new hoses, clamps, new 180 (& drilled out, as explained on ZR-1 FAQ) stat, & flushed the system. I then used distilled water, water wetter and 10% Prestone. So big mistake using Prestone (as I had read), it has taken a month but I will be receiving my GM antifreeze tomorrow via GM Direct. Then I will re-flush the system and make it 10% with the GM green stuff...I don't drive it in freezing weather & it stays in a heated garage.

So I think I have it right, finally...:icon_stud

[HAWAIIZR-1]

Per recommendation of someone here I went with Napa that meets the specs.

[Bell Curve]

About a month ago I read a number of antifreeze threads and freaked out! Last year I had installed all new hoses, clamps, new 180 (& drilled out, as explained on ZR-1 FAQ) stat, & flushed the system. I then used distilled water, water wetter and 10% Prestone. So big mistake using Prestone (as I had read), it has taken a month but I will be receiving my GM antifreeze tomorrow via GM Direct. Then I will re-flush the system and make it 10% with the GM green stuff...I don't drive it in freezing weather & it stays in a heated garage.

So I think I have it right, finally...:icon_stud

Prestone doesnt make any type of the good stuff:confused:

[95ZR1#418]

Prestone doesnt make any type of the good stuff:confused:

The posts I read, everyone agreed that the Prestone is essentially Dex Cool.

[Hib Halverson]

Straight water + 1.5 bottles of Red Line Water Wetter changed every two-three years.

170° thermostat

Stock hoses

Fluidyne radiator

Lower fan on temps

[vilant]

I used Turbo Power. Was at Pepboys and meets GM 1825M specs.

[lfalzarano]

From an old post from Marc

Join Date: May 2007
Location: Addison IL
Posts: 195
Default Coolant Recommedation
The question often comes up about what is the best coolant for the LT5 engine. I recommend the OE style conventional green coolant. I have found that Dex-Cool causes swelling of the OE LT5 head gasket.

Since it is possible that organic corrosion inhibiter softens the head gasket material, coolant containing organic corrosion protection should not be used in the LT5 engine. The possible values of using organic corrosion protection are small. Dex-Cool claims extended service interval and possible longer water pump seal life. It is not worth taking even a small risk for those benefits since the consequences of head gasket damage are huge.

Use coolant that has the following characteristics:
- Labeled, “For older vehicles.”
- Coolant that is colored green
- Texaco UPC number 76568 12016
- Chevron UPC number 23968 10000
- GM specification 1825M coolant. The current pn is 12378560.
- AutoZone part number 540722. The UPC number is 52948 59081.
- Blue Mountain UPC number 74804 01858

The green coolant might not be available in a brand that you like. However the correct formulation is more important than the brand. Avoid “Universal” coolant. There is no need to compromise when the green coolant is available. Retailers like universal products because they reduce inventory costs, universal coolant is not the best for your LT5, the conventional green coolant is.

For detailed information about my observations of LT5 head gasket swelling see:

http://www.zr1specialist.com/HAT%20Web/articles/evidence%20that%20dexcool%20harms%20the%20cylinder %20head%20gasket.htm



Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

Some of the p/n have changed since 2007, since I went with the GM Brand12353

[hiperf406]

I used the long life orange A/F for a few years then I read on ZR1 Forum that was a no-no
as it caused corrosion & was hard on heater cores. So I switched back to the approved green blend that GM recommended.

[Paul Workman]

I used the long life orange A/F for a few years then I read on ZR1 Forum that was a no-no
as it caused corrosion & was hard on heater cores. So I switched back to the approved green blend that GM recommended.

Marc Haibeck wrote an article (http://www.zr1specialist.com/HAT%20Web/articles/Evidence%20that%20DexCool%20Harms%20the%20Cylinder %20Head%20Gasket.pdf) on this, some time back - on his web site. I defer to him/his article:

"My Recommendation
Since it is possible that the head gasket material is softened by organic corrosion inhibiter, coolant containing organic corrosion protection should not be used in the LT5 engine. The possible values of using organic corrosion protection are small. Dex-Cool claims extended service interval and possible longer water pump seal life. It is not worth taking even a small risk since the consequences of head gasket damage are huge."