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My car is a 2017 Stingray with M7 trans. My owner's manual states the cooling system capacity is 11.8 quarts and to use a 60/40 mixture of DEX-COOL and clean drinkable water. My question is can DEX-COOL premixed 50/50 be used instead without any overheating issues? It's a real hassle to have to measure out 4.8 quarts of coolant and then 7.2 quarts of distilled water. Will 50/50 suffice?
I’m guessing that the 60% is coolant. If so I would mix it. You could round off the 4.8 to 5 qts. And 7.2 to 7 qts.
If the 60% is water, then the 50-50 would be fine in my opinion.
The manual for my 2016 Z06 says 40% Dex-cool and 60% water down to -18F. If temp. lower than -18F, then okay to use 50/50 mix. It cautions overheating if not mixed properly.
I’m guessing that the 60% is coolant. If so I would mix it. You could round off the 4.8 to 5 qts. And 7.2 to 7 qts.
If the 60% is water, then the 50-50 would be fine in my opinion.
The manual for my 2016 Z06 says 40% Dex-cool and 60% water down to -18F. If temp. lower than -18F, then okay to use 50/50 mix. It cautions overheating if not mixed properly.
We had two or three nights last month when the temperature dipped into that range (one night at -19 below). Although unusual for this part of the country, maybe with climate change now not so much.
The ratio is 40% coolant 60% water. Not all that hard to mix. When the 5 year coolant change is performed you need to drain and refill the cooling system multiple times until the drained fluid is clear. When the coolant is drained there are a couple of quarts that remain captured in the engine block and other locations in the system. Draining and refilling multiple times flushes the system and gets all of the old coolant out of the engine block. Each time you refill the system with clean drinkable water you run the engine without the pressure cap until the system is warm enough to open the thermostat. With the thermostat open you get better mixing of the clean and old fluid. Let it run a few minutes this way and rev the engine to about 2500 rpm a few times.
Once the drained fluid runs clear let the system empty, close the drain **** and refill the system by adding the proper amount of Dex-Cool to get to 40% of the capacity (4.72 quarts). Then top off with clean drinkable water. Once the system is topped off leave the coolant pressure cap off and start the engine again. Let it warm up to the point the thermostat opens again and rev the engine to about 2500 rpm and hold it at that level for a minute or so a couple of times. That helps get the air out of the system. Shut the engine off and let it cool down then check the coolant level. If it has dropped add more clean drinkable water until it is topped off again and install the pressure cap. After that, I usually take the car for a 10 to 15 mile drive then recheck the coolant level once the engine cools. If it has dropped I will add some more water.
One thing to think about is if the amount of water in the engine block is 2 quarts and you use a 50/50 premix product the mixture will come out at 41/59. If it is 3 quarts the mixture will come out 37/63. I never use premix since I don't like paying a rip-off price for 2 quarts of water in every gallon of antifreeze.
Bill
Last edited by Bill Dearborn; Mar 4, 2021 at 12:45 PM.
is excellent. I used 8 gallons of distilled water to flush the system three times. The water was clear when I finished. I used one gallon of Prestone Dexcool for GM cars plus another .6 gallon from a second bottle. Walmart had the best price.
If you have a shallow pan you don't even have to jack up the car or get under it. Everything can be done from the top. I found this out after I had the car up. It takes a while to drain the car, bring it back to operating temperature then refill it. But the job is easy. BTW don't back the pitcock valve out too far. The draining hot water will blow it out. Then you have to find the plastic valve
After the final flush, add the Dexcool and start adding distilled water. I filled the reservoir to the top line. Several iterations of running and cooling are required to completely mix the water and coolant. I did not measure the water I added. When the mixture was stable my Prestone antifreeze tester showed protection to -12 degrees.
Bill's method is straightforward and easy. That's how I changed out my coolant as well. One thing that I did was that after each draining, I would fill it back up with hot water, as this shortens the warm-up time. I did this three times (drain fill run) and that resulted in clear fluid draining out. Then, as Bill states, begin the final refill by first adding the proper amount of Dex-Cool antifreeze. I used 4.7 Quarts (note, on good measuring cups, it will also show ounces and since 32 ounces is one quart, add four quarts and 23 ounces (measure, not weight)). Then fill up with water. As Bill pointed out above, this accounts for the water that you cannot get out (block, heater core). Start the engine and add additional water as needed. Run until warm, (thermostat open) and verify that it is full. Let it cool and verify that it is full.
is excellent. I used 8 gallons of distilled water to flush the system three times. The water was clear when I finished. I used one gallon of Prestone Dexcool for GM cars plus another .6 gallon from a second bottle. Walmart had the best price.
If you have a shallow pan you don't even have to jack up the car or get under it. Everything can be done from the top. I found this out after I had the car up. It takes a while to drain the car, bring it back to operating temperature then refill it. But the job is easy. BTW don't back the pitcock valve out too far. The draining hot water will blow it out. Then you have to find the plastic valve
After the final flush, add the Dexcool and start adding distilled water. I filled the reservoir to the top line. Several iterations of running and cooling are required to completely mix the water and coolant. I did not measure the water I added. When the mixture was stable my Prestone antifreeze tester showed protection to -12 degrees.
Good tip on not having to jack the car up to get to the drain petcock. I'll be doing mine tomorrow and will definitely want to drain/fill it 2 or 3 times in order to get all of the old coolant out. Old coolant has no value, it doesn't cool as well as water and it no longer has any desirable coolant attributes.
I would reconsider using distilled water, however. You want a mineral-free (hence why GM calls for clean, drinkable water,) but you also want an ionically balanced water, something that distilled water is not.
We get this question all the time when talking to customers on our tech line: What is the best type of water to use in my cooling system?” In this post, we would like to address this topic, as the plethora of misinformation regarding this topic has easily made it the most misunderstood.
Many people have “heard” that distilled water is the best water to use in a cooling system. This is wrong! While it is certainly true that distilled water’s purity prevents electrolysis and scale/deposit formation, it unfortunately comes with a potentially very damaging side effect.
During the distillation process, water is vaporized into its gaseous phase, so all its impurities are left behind. These impurities include a number of minerals, including “calcium” and “magnesium,” the two components of water “hardness.” The water is then condensed back into its liquid phase, so the resulting liquid is pure water – in fact, some of the purest water on earth. But the problem is that when water is distilled, or “stripped,” of its minerals and impurities, the resulting solution is composed of chemically imbalanced “ions.” This leaves distilled water “ionically hungry,” so it will actually strip electrons from the metals in a cooling system as it attempts to chemically re-balance itself. As it chemically removes electrons from the metals of cooling system components, distilled water eventually does extreme damage that could lead to cooling system failure.
So what’s the answer? Softened water. During the water softening process, the same impurities and minerals are removed from water as during the distillation process – but with one very important distinction. Rather than STRIPPING the impurities from water, softening EXCHANGES the impurities with a sodium ion. The resulting solution is chemically and ionically balanced, making softened water very stable, very pure, and non-threatening to cooling system metals.
There seems to be a perceptual issue with regard to the usage of softened water in cooling systems by auto enthusiasts. Many mistakenly believe that because salt is added to water softeners, then softened water must contain salt, a substance of course known to be very corrosive. Nothing could be further from the truth. The salt you add to a water softener is NaCl, or sodium chloride.
During the softening process, only the sodium ion is exchanged into the water. Therefore, softened water does NOT contain corrosive salt.
What are the benefits of using softened water? Soft water lacks most of the impurities of tap water, meaning it far less conductive (i.e. less damage from electrolysis) and will not form deposits (i.e. less possibility of overheating). However, if you use Hy-per Lube Super Coolant, you don’t need to use softened water. Hy-per Lube Super Coolant contains molybdate, a form of the semi-precious metal “molybdenum,” which is proven to be extremely effective in preventing galvanic action and electrolysis – regardless of what type of water is used. Hy-Per Lube Super Coolant also contains polymer dispersants which keep water hardness in solution, thus preventing the formation of insulative scales and deposits. So regardless of whether you use softened water or tap water, you need not worry about these issues when you use Hy-Per Lube Super Coolant. This is actually one of the important benefits of the product, because not everybody has easy access to softened water.
But please – PLEASE! – do not use distilled water in your automotive cooling system.
How can I tell if my '19 Z51 A8 has the heavy duty cooling option V08 ?
Your RPO codes I believe are in your rear hatch area under your carpet, near where the battery is. But if you have an A8, you get the transmission cooler mounted horizontally underneath your heat exchanger (V03, I believe,) not the auxiliary radiator that comes with the M7 and V08.
Last edited by BigVette427; Mar 4, 2021 at 07:47 PM.
Lots of helpful information here gang, thanks. Although, I couldn’t get to my drain petcock without jacking it up. Maybe it’s harder with side skirts and a splitter? Either way, it’s fun to wrench on this car.
Except when racing, perhaps, one doesn't use just water, "ionized" distilled water, or otherwise. Instead, of course, it's mixed with antifreeze changing the basic chemistry.
Good tip on not having to jack the car up to get to the drain petcock. I'll be doing mine tomorrow and will definitely want to drain/fill it 2 or 3 times in order to get all of the old coolant out. Old coolant has no value, it doesn't cool as well as water and it no longer has any desirable coolant attributes.
I would reconsider using distilled water, however. You want a mineral-free (hence why GM calls for clean, drinkable water,) but you also want an ionically balanced water, something that distilled water is not.
This is an interesting article and can be misconstrued in conflict with the drain and fill instructions on anti-freeze product websites.
Distilled water should not be used by itself in an automobile cooling system and that is why it is important to mix that distilled water with the proper amount of anti-freeze such as Prestone, Peak, ACDelco Dex-Cool, etc.
The Prestone website drain and fill instructions explicitly state to use distilled water with their Prestone Concentrate.
The Peak website has instruction video's which also state to use distilled water with their anti-freeze concentrate. They also state the pre-mixed Peak anti-freeze contains their concentrate mixed with distilled water.
I believe the statement from Hyperlube is accurate in that it does not use the term anti-freeze and simply states distilled water should not be used without explaining completely that they mean distilled water should not be used by itself.
The ratio is 40% coolant 60% water. Not all that hard to mix. When the 5 year coolant change is performed you need to drain and refill the cooling system multiple times until the drained fluid is clear. When the coolant is drained there are a couple of quarts that remain captured in the engine block and other locations in the system. Draining and refilling multiple times flushes the system and gets all of the old coolant out of the engine block. Each time you refill the system with clean drinkable water you run the engine without the pressure cap until the system is warm enough to open the thermostat. With the thermostat open you get better mixing of the clean and old fluid. Let it run a few minutes this way and rev the engine to about 2500 rpm a few times.
Once the drained fluid runs clear let the system empty, close the drain **** and refill the system by adding the proper amount of Dex-Cool to get to 40% of the capacity (4.72 quarts). Then top off with clean drinkable water. Once the system is topped off leave the coolant pressure cap off and start the engine again. Let it warm up to the point the thermostat opens again and rev the engine to about 2500 rpm and hold it at that level for a minute or so a couple of times. That helps get the air out of the system. Shut the engine off and let it cool down then check the coolant level. If it has dropped add more clean drinkable water until it is topped off again and install the pressure cap. After that, I usually take the car for a 10 to 15 mile drive then recheck the coolant level once the engine cools. If it has dropped I will add some more water.
One thing to think about is if the amount of water in the engine block is 2 quarts and you use a 50/50 premix product the mixture will come out at 41/59. If it is 3 quarts the mixture will come out 37/63. I never use premix since I don't like paying a rip-off price for 2 quarts of water in every gallon of antifreeze.
Bill
Bill,
Would you consider it worthwhile to run the heater while flushing? To be sure the heater core and associated hoses were flushed too? Or does the heater core getting flushed occur sufficiently without turning on the heater?
Last edited by thompstl1; Mar 6, 2021 at 05:58 AM.
Engine Coolant Question
