Re: Modern Engine Swaps: Dexcool or Old School?
 

Present formulations of Dexcool mixed 50/50 with distilled water WILL NOT cause any issues, Drain & refill every 50,000/5 years.....No flush necessary.

Conventional Green silicate coolant 50/50 with distilled water.....Drain & refill every 24,000/2 years.

Re: Modern Engine Swaps: Dexcool or Old School?
 

Some more info for what it is worth !

Red
I changed my truck to green, then started to worry about it. So, I called my buddy, the GM design engineer who worked on the design and testing of the LS engines--and he spent a lot of time with the truck 5.3 engine.
He said to use only Red!
He had about 4 or 5 hot rods at the time with various chevy engines in them, including LS engines.
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Re: Modern Engine Swaps: Dexcool or Old School?
 

ok...but did he bother to explain WHY its better? I kinda doubt anyone working for GM would be told the stuff sucks by the people who make it

Re: Modern Engine Swaps: Dexcool or Old School?
 

I think the purple stuff works the best. :metal:
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Re: Modern Engine Swaps: Dexcool or Old School?
 

OAT Extended Life Coolant lasts longer, No Silicate to drop out of the coolant....So you don't have to Flush the sediment out when it comes time to change it.

IAT = Inorganic Additive Technology......Silicate (Large amounts) is the primary corrosion inhibiter & is a better faster acting additive, But VERY short lived because of the Silicate dropping out of suspension over time. Conventional Green Coolant.

OAT = Organic Acid Technology......Silicate Free, Organic Acids take place of Silicate as the primary corrosion inhibitor.
Dexcool & other OAT coolants.

HOAT = Hybrid Organic Acid Technology......Small amounts of Silicate(Hybrid) & Organic Acid to control corrosion.
Zerex G-05 Yellow coolant. There are some G-05 HOAT coolants that are orange, John Deere G-05 is green.

Re: Modern Engine Swaps: Dexcool or Old School?
 

Dexcool can cause problems with older style gaskets. A lot of GM cars and trucks began getting updated gaskets after dexcool was around for a few years. I noticed that GM intake and waterpump gaskets changed from having a red/orange material to having a light blue one instead. It seemed to take care of the leaking problems. I haven't really seen clogging, but I only worked on newer cars that came with dexcool originally.

Re: Modern Engine Swaps: Dexcool or Old School?
 

Look up the article "coolant confusion" by motor age magazine. it goes into detail all styles of coolant. As a dealer mechanic of 30 plus years what i noted was dexcool in a system that had what i call a burp bottle for an overflow (non-pressurized) bottle got what i called hoatmeal inside it. The same engine with a pressurized overflow bottle that had a screw on pressure cap didn't have the condition. I'm using G-05 antifreeze in my ls 5.3 (2001 vintage). It's been 3 years with the original brass heater core, 2001 aluminum radiator (from the organ donor) and no issues. Coolant still looks great with no sediment, or discoloration.

Re: Modern Engine Swaps: Dexcool or Old School?
 

I have a '99 Chevy Tahoe and almost two years ago did a good flush and re-fill with the green stuff. Talked to a mech. friend of mine and he is totally sold on going "gren" but really emphasized (sp?) about doing a good flush. At the same time I put in a new thermostat (195 degree) and a re-useable gasket. No problems and runs cool in the summer and great heat in the winter.

Re: Modern Engine Swaps: Dexcool or Old School?
 

Thanks for spelling that out!
Now more questions, I will be looking into the G-05!!!

I wonder what Jag uses in there aluminum engines that last for 5 years and cost 75.00 a gallon !!!!

Re: Modern Engine Swaps: Dexcool or Old School?
 

another good article...august 2004 motor magazine "coolant confusion"...more chemistry "why's" than the motor age one...tried to post url but it wouldn't open so just search it...

Re: Modern Engine Swaps: Dexcool or Old School?
 

Anyone using Evan's coolant? I've read about it over the years but haven't used it yet. I've been planning to switch over most of my vehicles.

Re: Modern Engine Swaps: Dexcool or Old School?
 

I just put a 2004 ls lq9 6 litre in my 1968 c10. I am using the Evans waterless coolant. I am using it with the stock two core rad. I have about 1000 km on it so far and no problems. It cools good. It never goes bad or needs to be replaced. It also doesn't boil or bill pressure in the coolant system. You can get the engine up to operating temperature and then take the rad cap off. I thought that was a good thing so hopefully the original rad or heater core won't leak.
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Re: Modern Engine Swaps: Dexcool or Old School?
 

I just use a unisevrral coolant that mixes wjth any color coolant buts its a long life coolant also.
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Re: Modern Engine Swaps: Dexcool or Old School?
 

well, since we are all throwing stuff out here, how about the stuff that says it meets gm 1825m/1899m on the back of it, I work for a Detroit diesel dealer and can buy it at cost, purple concentrated power cool with sca's for Detroit diesel's but it has these 2 gm ratings on the back. I have a 97 vortec 5.7 I just built and trying to save a few bucks where I can, I assume (that gets me in trouble sometimes) since it meets these gm specs, I should be able to run it. I tried looking up these specs but couldn't come up with a solid answer. I have ran green in just about everything with no problems, I have also ran CAT ext life red with no problems, but I'm not accessible to cat coolant for cheap anymore.

Re: Modern Engine Swaps: Dexcool or Old School?
 

You will be fine using that coolant, Supplemental Coolant Additive (SCA) are for the "Wet Sleeves/Cylinder liners" Won't help nor hurt.

Re: Modern Engine Swaps: Dexcool or Old School?
 

Thanks, i was always understanding that the sca's were for preventing cavatation in block/sleeves, but hadnt really thought about it hurting/helping anything in a normal block. Thanks again for the clarification.
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Re: Modern Engine Swaps: Dexcool or Old School?
 

I have a 2011 Acadia. I got a GM letter in the mail saying that they will top up my antifreeze free of charge due to a low coolant level problem. Basically if the coolant gets low and air is entered into the coolant system it will create a greasy sludge that is very next to impossible to remove. I was lucky to catch it in time on a 2000 Sonoma that my son drives. I had a 2002 Grand Prix that the intake gaskets failed due to the coolant eating them. I have had the green stuff in my 1987 Iroc and 69GMC and flushed it every couple years with no issues. I will be flushing my 2007 Duramax soon and the Acadia when its off Warranty. Dexcool in my opinion is a long life antifreeze that creates more problems than the less service it was intended for.