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%20W...d%20gasket.htm

Re: Coolant Recommedation
 

The detailed information attached describes The three causes of LT5 Overheating and resulting Cylinder Head Gasket Failures which in itself is as important as using the wrong coolant making the overheating issues even more serious :read2:


Thanks Marc :thumbsup:

Re: Coolant Recommedation
 

Marc


Thanks for posting this!!! This question comes up and most of us can't remember what exactly is safe to use

:cheers:

David

Re: Coolant Recommedation
 

Thanks Marc, doing coolant this weekend. Really nice to have confirmation of what to use from a trusted source.

Re: Coolant Recommedation
 

Great Info.

Re: Coolant Recommedation
 

Good info there Mr. H...

I would NEVER recommend GM Red coolant.

In 4 vehicles I've owned with the Dex-sludge, ALL 4 had the 'plug', including an '02 1-ton, bought new, which was my personal vehicle of my delivery fleet business. All were immaculately maintained by me, and the 1-ton stayed running. After 100k, about 14 months, it had the 'plug'.

I think GM lost a class action over this issue...

Re: Coolant Recommedation
 

The orange Dexcool, will not tolerate any exposure to air, it will form an acidic sludge that will etch into cast iron heads. Dexcool is an OATs coolant (Organic Acid Technology).

Stick to the green coolant, but if you do, you must perform the coolant service at shorter intervals.

Anyone know if the orange Dexcool was the factory fill on the 1996 LT1 and LT4 Y-bodies? In the trucks it started with OBD2 in 1996.

ANother important thing is when you switch from the orange extended service interval Dexcool over to green Dexcool, be sure to flush all the orange out. BAd things happen when green and orange mix.

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Info on lawsuits

[I]GM Coolant Settlement Could Cost Hundreds of Millions
By Edward Niedermeyer
- 990 Views
The General has settled a class-action lawsuit claiming damages from its "Dexcool" coolant, agreeing to pay up to $800 each to customers who can prove damages. Plaintiff attorneys estimate that the final number of claims could top $20 million, a bill which would cost GM of hundreds of millions of dollars. "It could be multiple nine figures; it depends on how many people make the claim," co-counsel for the plaintiffs, Jack Brady tells the International Herald Tribune . "I think it could be a huge settlement." Of course, while the people who had to replace manifold gaskets and heater cores get between $50 and $800 for repairs, Mr Brady and his co-counsels will pocket up to $23 million in fees and $2.8 million for expenses. Still, if you own a GM vehicle with the 3.1-liter or 3.4-liter V6 engines for model years 1995 to 2003; the 3.8-liter V6 engines for model years 1995 to 2004; or the 4.3-liter V6 engines for model years 1995 through 2000 and have had to pay for coolant-related damages, you should check dexcoolsettlement.com to file a claim.



GM agrees to settle class-action lawsuits tied to engine coolant

The Associated PressPublished: March 26, 2008



Listen

Info on the lawsuits
KANSAS CITY, Mo.: General Motors Corp. has agreed to settle a series of class-action lawsuits claiming a faulty engine coolant damaged thousands of customer vehicles.
Under the settlement, GM would reimburse class members between $50 and $800 for repairs linked to Dex-Cool, an orange coolant that GM included in cars and trucks beginning in 1995.
The total cost to GM will depend on the number of customers claiming damages, but the plaintiffs' attorneys estimate the settlement could cover up to 20 million initial and secondary buyers of GM vehicles that used Dex-Cool. They also say the price tag could reach the hundreds of millions of dollars.
A California state court gave preliminary approval to the settlement last week and a Missouri court plans to consider it Friday.
"We fought for about five years to recover monetary damages for people that would be meaningful and I think we achieved that," said San Francisco plaintiff attorney Eric Gibbs, who estimated most people spent between $600 and $900 for repairs. "The recovery for most of the people will be pretty good."
GM spokesman Tom Wilkinson said the company was not admitting any wrongdoing but is settling the case to cut down on legal bills.
"Our experience with Dex-Cool is that when the cooling system is kept full and properly maintained we haven't seen any problems," he said. "These kinds of things appear to be issues of low coolant, which isn't unusual with high-mileage vehicles, so we decided to agree to the settlement."[I]

Re: Coolant Recommedation
 

My 91 ZR-1 has the Dex-cool in it. It was in there when I bought it. What procedure should I take to change over to the green?

I've read stories about air getting trapped in the system while refilling.

Re: Coolant Recommedation
 

I was able with all 4 GM's with Dex Red [Orange], to get the 'plug' out - IT FLUSHED FROM THE HEATER CORE EVERY TIME - with pressure from a garden hose. I'd put the hose to every coolant orifice I could find, and reversed from the other end when possible.

See if you can get feedback from Marc H on flushing LT5. Deference on alls' part here (save a few), goes to him...

There's a flow schematic recently posted here somewhere...

Re: Coolant Recommedation
 

Re: Coolant Recommedation
 

Timing for this is perfect.. I need to pull the top end off to fix a leaky gasket (breather box) so I may as well replace the coolant this time

Re: Coolant Recommedation
 

Any value in use Water Wetter? I have used it with much success back in the day with my racebikes. We did change the coolant religiously every 3 months though to avoid any corrosion.

Re: Coolant Recommedation
 

Many benefits to the Water Wetter as a "coolant" BUT it does freeze. As a coolant it's my understanding that it cools less the "pressurization" required by water and conventional coolant mix. I understand that actually if Water Wetter were in a cooling system and if you needed to "top off" with a conventional "deionized/distilled" water mix the Water Wetter can be reclaimed by bringing the product to slightly higher than 212* and boil off the water. I've no first hand knowledge of that but it seems likely.

Perhaps some one that is a "user" could comment more directly!

Re: Coolant Recommedation
 

To the top

MANY ask about this

Please make this a sticky

:cheers:

David

Re: Coolant Recommedation
 

Has anyone tried running evan's coolant? It uses no pressure as a coolant. I know some guys in the 2 stroke world and turbocharged world swear by it. There are power gains as well as less stress on components from it. It is not corrosive either.

http://www.evanscooling.com/

Re: Coolant Recommedation
 

done :cheers:

Re: Coolant Recommedation
 

The Evans coolant is a waterless liquid with an approx. 356°F boiling point at 1 BAR (14.7 psi) natural atmospheric pressure at STP(Standard Temp and Pressure-equivalent to driving around without a rad cap, thus allowing no cooling system pressure to build). It's mostly Propylene glycol.
Good thing about Propylene glycol is that its many times less toxic than the conventional Ethylene Glycol coolants. Its generally regarded as safe for canines and other pets. (by no means should this relax safety around pets and children, Evans coolant is not pure PG when new, and would be regarded as contaminated after a service interval in an LT5 or any other engine. But if my dog accidentally ingested a coolant, I would rather it be Evans.)

So safe in fact that many of the intravenous and Intramuscular medications that I give to people use Propylene Glycol as a diluent for meds that do NOT dissolve in water. PG is also used to carry the nicotine and flavours in the "juice" that smokers use in electronic cigarettes.

Because of its higher no pressure boiling point, nucleate boiling is prevented. As soon as any liquid boils, the resultant vapour or gas drastically reduces heat transfer from the metal into the liquid.
Think of nucleate boiling as the small bubbles that occur on the bottom of a pot of water on the stove. Water boils at 212ºF, and although the entire pot of water may not be 212º, the liquid temps right along the bottom of the pot are high enough to boil.

It is important to note that both Propylene and Ethylene Glycols are corrosive to metals when exposed to air/oxygen if not mixed with inhibiter.

Air cools rad fins, rad cools coolant, coolant cools engine, its all about thermodynamics.

EDIT: I simply concentrated of one aspect of the Evans cooling "system", there are many other advantages other than just the boiling point and low toxicity)

Re: Coolant Recommedation
 

What would a "coolant thread" be without my lunatic-fringe alternative.

For most of the 20 years I've owned "Barney" my purple '95, I've never run any antifreeze at all in the cooling system. Just straight water and one bottle of one of the two leading coolant additives, Gibbs Driven "CSP" or Red Line "Water Wetter".

Why straight water?

Water is a better coolant because it absorbs more BTUs per gallon than does a 50/50 mix of water and antifreeze. Of course, when you don't use antifreeze you MUST have some other form of the anti-foaming and anti corrosive chemicals that come in antifreeze. Radiator Relief or Water Wetter supply that chemistry. In fact, Water Wetter uses a calcium-based corrosion inhibiter similar to that in Dexcool. Additionally, both products contain a "weting agent" which further improves water's ability to cool by enhancing the transfer of heat from the cylinder head and block to the cooling jackets.

Now...the cautionary statements:

1) For obvious reasons, you can't use straight water if your car is subjected to below freezing temperatures when it's parked overnight or stored.

2) You must change that coolant mix every 24-months regardless of mileage.

Re: Coolant Recommedation
 

I was surprised to find Dex-Cool in the Lingenfelter...the fluids had just been changed when I bought it, so I didn't worry about it for quite some time, then when I found Dex-Cool, I just supposed to change it at the next available time.....well that was when I changed the starter a while back.....I flushed it three times with straight water and the water ran very clear. I decided to do the fill with Pentosin Pentofrost NF. What sold me was "Mercedes Benz all years" "Porsche 924,928,944,968 all years" "BMW all years"
http://www.pentosin.net/f_antifreeze.asp
Thoughts?
:happy1:

https://im1.shutterfly.com/media/47a...D720/ry%3D480/

Re: Coolant Recommedation
 

Here's an update about green formula coolant availability. I believe that it is still important to stay with the OE type color coded green coolant. Green coolant can be hard to find. Some auto supplies will try to sell "universal" or some other coolant because that is all they have. It might take some searching but green coolant is still available.

As of this date AutoZone has it in their house brand. Part number A003.

NAPA has it in their house brand. Part number NAF1GAL. The NAPA near me also has the Zerex brand. Part number ZRX ZX001.

A local independent auto supply stocks it because they want to support the classic car market. It's labeled FVP Original Green Formula. Part number FVPGreen-Gal. It's distributed by FVPparts.com.

Re: Coolant Recommedation
 

RADIATOR COOLANT additional photos of Marc's recommendations
You want to only use the green coolant. They have it at Napa and it meets 1825M GM Spec.

For Zerex the first gallon is called Regular Green Coolant (GM 1825M), the second gallon is called Original Formula (GM 1825M). Zerex ZXRU1 is 50-50 and Zerex ZX001 is undiluted. The third gallon is NAPA coolant (GM 1825M).

http://partimages.genpt.com/partimages/213991.jpgORhttp://ecx.images-amazon.com/images/I/31jb-ZubjrL.jpgORhttp://partimages.genpt.com/partimages/213967.jpg

NAPA

Re: Coolant Recommedation
 

Marc,
Thanks for updating us.
Besides the OEM head gasket in your experience have you seen any other area of the LT5 engine that is negatively effected by not using the recommended 1825M type antifreeze?

Re: Coolant Recommedation
 

I have not noticed any other particular corrosion problems Phil.

Re: Coolant Recommedation
 

All,

Was just at Autozone. Part # 540722 now has code AZA003 on it. Green conventional. It looks to be the correct product.

Marc, can you confirm that the AZA003 is still the correct coolant?

Thanks

Coolant Recommedation
 

I could not find GM 1825M in Japan, not even on military bases since they only carry Prestone. I almost settled for Prestone, but after consulting with Marc, I kept searchIng the inter web. Fortunately, Advance Auto Parts could ship Carquest Conventional Green stuff to me and it’s on the way. [Thank you Marc! ATTACH]7016[/ATTACH]


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Re: Coolant Recommedation
 

I think that the AutoZone AZA003 is a good choice.

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Buy premixed? Or 50/50 myself?

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Premix is just easier. Makes no difference.
H

Re: Coolant Recommedation
 

Hi guys,
i'm from italy and i cant find your product. Do you think that a common green coolant is good for my lt5?
How many liters need?
Thanks

Re: Coolant Recommedation
 

http://www.zr1.net/forum/showthread.php?t=21601

15 quarts or 14.2 liters

http://www.zr1specialist.com/HAT%20W...%20Coolant.pdf




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Re: Coolant Recommedation
 

Thanks

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Is this peak antifreeze the correct kind for a 90 ZR1. Trying to support the local hardware store but don't want to get the wrong type

Re: Coolant Recommedation
 

Green = Good!

Red Bad
Orange bad
Marty

Re: Coolant Recommedation
 

Has anyone ever heard of or used Mannheim motor oils and lubricants?
They also make coolant.
It?s a company from up here in Canada that make really great products.
I did a Coolant system flush and oil + filter change this weekend and the car drove lovely.