Adjusting coolant strength

[BEL]

Presenting in my 2016 Sierra 2500HD truck the coolant strength is -30. I would like to bring it up to at least -35, if not -40. Most of what i have read says to drain some of the coolant. Can I siphon a litre or two from the reservoir and replace it with full strength Dexcool. BEL

[elkhunter11]

Take it out of the rad and replace it with some pure antifreeze, so it mixes immediately with what is in the rad, and then with the coolant in the engine. The coolant in the reservoir will take time to mix with the rest of the coolant, so if it gets really cold soon, the antifreeze may not fully mix with the coolant in time.

[BEL]

That was another thought i had. I have seen bad experiences with people opening up the radiator cap when hot. I thought the reservoir was safer but your idea of mixing quickly makes sense. Thanks. BEL

[does it ALL outdoors]

Be a good time to drain that Dex-fool and replace it with regular green antifreeze. That Dex-fool eats head gaskets among a laundry list of other problems. When it ate mine a mechanic for GM told me without hesitating that it was likely the orange junk that ate them and to swap it out and highly recommends that everyone does. GM was successfully sued over that stuff its THAT bad. Good for you if you have been using it problem free, but you are playing with fire.


https://www.consumeraffairs.com/automotive/gm_dexcool.html

[Digger1]

They were still putting Dexcool in vehicles in 2016? I wonder what’s in mine.

[BEL]

Wow! Did not know about possible damage from Dexcool, although I did hear years ago to switch it out. Don’t think it will void my warranty but will check that out. Thanks for the heads up. BEL

[JBE]

Probably no rad cap on the 2016, my 13 don't have one. You can take a hose clamp off and drain some coolant.

[^v^Tinda wolf^v^]

I was under the impression that dexcool gels and doesn't freeze. I haven't touched the coolant in my 2013 2500hd since new and it hasn't froze on me anyways. I also heard the green stuff is bad for aluminum blocks.

[Coiloil37]

I drive a cummins so I don't know what your engine requires but I'll say it's important you match what your vehicle has in it and if you replace it, choose something compatible with your engine. There are a lot of good truck resource websites to find the info you need. Bobistheoilguy.com is where I would start reading, don't trust any of the muppets at auto parts store as they often know nothing about your engine and which coolant it requires. As already seen in this thread, guys will start shooting from the hip regarding coolant types without knowing what your duramax requires or was spec'ed for. Do your own research and or, if your just topping it up use the same type of coolant as what it came with.

It took me a lot of reading to make sure I knew what I was doing when I flushed my coolant at the 5 year mark and there's a lot of ways to choose the wrong coolant if your not careful. Every engine manufacture uses different materials in their engines and require a compatible coolant. HOAT/ OAT are different technologies and need to be matched appropriately. Wet sleeved engines require filters with SCA's like I run on my rigs engines and high silicate, old school, green coolants are hard on your water pump regardless of what your putting it in. It's been to long since I've done the research so I've forgotten a lot but you can find all the answers you need online if you look for them.

[leeelmer]

Get the dexicool out right away
Get a rad shop to flush and fill it with good quality diesel antifreeze
Thousands of posts on fourums about the bad things it does to your motor.
No clue why gm still uses that crap
Changed lots of head gaskets at my shop because of it.

[^v^Tinda wolf^v^]

I don’t want to get off topic but why are they still using Dexcool if it compromises the integrity of your engine? Anyone...:thinking-006:

[CaberTosser]

I'll often have to adjust the % of glycol in hot water heating systems, same thing but just on a larger volume. I generally prefer to shut down the system, drain off a slightly excessive amount and then fill with 100% glycol. Its easier to dilute back down a bit than it is to try to up the percentage.

With a vehicle there should be a known volume to the cooling system so that helps with the ability to use math to calculate how much to drain & add. On large systems with unknown volume I can add a marker chemical and let that mix for a day or two. I can then analyze that to determine its dilution level and extrapolate the overall system volume from there.

[Dr. Phil A]

The dex cool turns acidic after so many years or miles then starts to eat gaskets.
Fixed many 5.7 litre gm intake gaskets and did the head gaskets at the same time as it was only a month later that they would go.

[^v^Tinda wolf^v^]

Thanks for the info doc, going to change my freeze the next time I take the old girl out😁

[Ddawg]

Presenting in my 2016 Sierra 2500HD truck the coolant strength is -30. I would like to bring it up to at least -35, if not -40. Most of what i have read says to drain some of the coolant. Can I siphon a litre or two from the reservoir and replace it with full strength Dexcool. BEL




I would have it rechecked, being 2016 it’s should be good from the factory. Dex-Cool is rated to freeze at -36.7 C so you won’t get -40 rating. Do some research on Dex-Cool, it’s has to be maintained to the proper level and tested for PH and Alkalinity periodically, no different than the green antifreeze. And it needs to be replaced as it does ware out. As far as being harmful to you engine that’s BS, why would GM risk using it in a 12 thousand dollar Diesel engine, if it was harmful?
In 17 yrs driving GMs, 9 trucks over 1.5 million kilometers, I have never had a gasket fail, only one water pump at 450,000, I will take my chances and stick with the Dex-Cool.





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[Mayhem]

The dex cool turns acidic after so many years or miles then starts to eat gaskets.
Fixed many 5.7 litre gm intake gaskets and did the head gaskets at the same time as it was only a month later that they would go.

I would have it rechecked, being 2016 it’s should be good from the factory. Dex-Cool is rated to freeze at -36.7 C so you won’t get -40 rating. Do some research on Dex-Cool, it’s has to be maintained to the proper level and tested for PH and Alkalinity periodically, no different than the green antifreeze. And it needs to be replaced as it does ware out. As far as being harmful to you engine that’s BS, why would GM risk using it in a 12 thousand dollar Diesel engine, if it was harmful?
In 17 yrs driving GMs, 9 trucks over 1.5 million kilometers, I have never had a gasket fail, only one water pump at 450,000, I will take my chances and stick with the Dex-Cool.

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This…it’s no different that tires, diffs, etc. all about maintenance.

Been running DEX-COOL for almost 2 decades without any issues but there are a few things that are essential for longevity: You must change it religiously every 5 years. Drain the reservoir, rad, hoses, any other passages AND the block. It may look like perfectly good, normal coolant but it needs to be changed. I buy the concentrate and mix only with distilled water. Here is the part I think most people miss - Add ground up Cooling System Seal Tabs GM P/N 10-108 12378255 (very inexpensive, even from GM) as per the instructions to the mix prior to refilling. The tabs "seal tiny imperfections in gaskets and prevent premature water pump leakage but also inhibit the formation of rust and scale, neutralize pH imbalances and control electrolysis".

http://www.acdelco.com/auto-parts/vehicle-maintenance/mechanical-repair/cooling-system-seal-tabs.html

[RZR]

This…it’s no different that tires, diffs, etc. all about maintenance.

Been running DEX-COOL for almost 2 decades without any issues but there are a few things that are essential for longevity: You must change it religiously every 5 years. Drain the reservoir, rad, hoses, any other passages AND the block. It may look like perfectly good, normal coolant but it needs to be changed. I buy the concentrate and mix only with distilled water. Here is the part I think most people miss - Add ground up Cooling System Seal Tabs GM P/N 10-108 12378255 (very inexpensive, even from GM) as per the instructions to the mix prior to refilling. The tabs "seal tiny imperfections in gaskets and prevent premature water pump leakage but also inhibit the formation of rust and scale, neutralize pH imbalances and control electrolysis".

http://www.acdelco.com/auto-parts/vehicle-maintenance/mechanical-repair/cooling-system-seal-tabs.html

BINGO; we have a winner.