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my 2019's antifreeze is 5 years old (car was built 31 Aug2019). I was wondering if anyone has flushed and replaced the orange GM fluid with the green antifreeze? When do I need to change my current fluid based upon experience and not GM service life recommendations. Any ideas and or suggestions are appreciated.
Coolant color is less important than the formulation/specification. According to page 244 of the Owner's Manual, our cars require DEX-COOL that meets GM Standard GMW3420.
my 2019's antifreeze is 5 years old (car was built 31 Aug2019). I was wondering if anyone has flushed and replaced the orange GM fluid with the green antifreeze? When do I need to change my current fluid based upon experience and not GM service life recommendations. Any ideas and or suggestions are appreciated.
Why would you use the old IAT coolant? I don't think it is formulated the same as the DexCool which is OAT. The corrosion inhibitors might be different. If you want to change it, you could but I would do some testing to make sure it works. Not sure it is going to be worth the laboratory testing costs though.
I don't know why you would try to change fluid types. I used Prestone Dex-Cool. Open the radiator drain valve, fluid drains through the radiator mount. If what comes out is clean, and after five years it should be, refill with 40% Dex-Cool 60% water mix and you are done.
Radiator outlet
Last edited by Dave McDufford; Oct 16, 2024 at 05:59 AM.
If what comes out is clean, and after five years it should be, refill with 40% Dex-Cool 60% water mix and you are done.
Why not flush it every 5 years to get all the coolant out? There are lubricants and corrosion inhibitors that are in play. Dropping what is in the radiator is easy but that leaves half of the old coolant which might be "worn out" over time, doesn't it? Isn't that why they ask for coolant flushes after X miles or Y years?
Why not flush it every 5 years to get all the coolant out? There are lubricants and corrosion inhibitors that are in play. Dropping what is in the radiator is easy but that leaves half of the old coolant which might be "worn out" over time, doesn't it? Isn't that why they ask for coolant flushes after X miles or Y years?
The GM Service Manual says that once you have drained the system (see above), "Follow the appropriate procedure based on the condition of the coolant. Normal in Appearance - Follow the filling procedure or Discolored - Follow the flush procedure".
So GM sees no reason to flush in all circumstances and I trust their judgement.
The GM Service Manual says that once you have drained the system (see above), "Follow the appropriate procedure based on the condition of the coolant. Normal in Appearance - Follow the filling procedure or Discolored - Follow the flush procedure".
So GM sees no reason to flush in all circumstances and I trust their judgement.
How do you drain the system when you are just dropping what is in the radiator? I interpreted system as the entire thing from radiator to heater core to engine. I would probably say that I won't have flush it to get sediment out from the bottom of the block but I would prefer to get all the old fluid out. I sent it to the dealer to do a fluid exchange.
How do you drain the system when you are just dropping what is in the radiator? I interpreted system as the entire thing from radiator to heater core to engine. I would probably say that I won't have flush it to get sediment out from the bottom of the block but I would prefer to get all the old fluid out. I sent it to the dealer to do a fluid exchange.
How about draining the radiator, filling it, then driving your car. Then after so many cycles of cooling and heating of the “system “, drain the radiator again, and judge the color of the fluid.
Drain coolant at radiator petcock, fill with potable water at reservoir, run engine until warmed up (thermostat opens), drain. If not clear - repeat.
When radiator drains clear, add 4.5 qt of Dexcool (40% of 11.3 qt cooling system capacity), top off with potable water. Run engine with radiator cap off until warmed up, top off with potable water.
Drive normally, recheck coolant level and top off as needed a couple times.
Take used coolant and water used to flush to your auto parts store for recycling.
How about draining the radiator, filling it, then driving your car. Then after so many cycles of cooling and heating of the “system “, drain the radiator again, and judge the color of the fluid.
Just sayin!
Sure, but why bother to judge the color? Might as well test it with test strips. I usually go to truck stops that use that stuff daily so it is fresh, buy one and use it. Reading a test strip would be easier than looking at the coolant and guessing if it is good, I would think. I went for a flush last year and it was pretty simple. One and done. Flush out the old, bring in the new.
How do you drain the system when you are just dropping what is in the radiator? I interpreted system as the entire thing from radiator to heater core to engine. I would probably say that I won't have flush it to get sediment out from the bottom of the block but I would prefer to get all the old fluid out. I sent it to the dealer to do a fluid exchange.
GM publishes extensive Service Manuals for each of the vehicles it manufactures. I have a copy the 2018 Corvette edition (4 very thick books, which incidentally is the last hard copy version available) and have access to the electronic versions for later years. I follow their instructions when I work on my Corvettes.
What I indicated above are the "official" GM instructions on how to service the cooling system at the five-year point. If you want to create your own better method - have at it.
An additional point to make is these engines and heads are aluminum which does not rust like the iron blocks. There may not be any iron anywhere in the cooling system so you would expect the coolant to stay cleaner..
Also, I think RonC7's method above is the best way to go if you feel the need to flush everything - it is also one of the "official" methods mentioned in the Service Manual.
Last edited by Dave McDufford; Oct 16, 2024 at 05:58 AM.
Sure, but why bother to judge the color? Might as well test it with test strips. I usually go to truck stops that use that stuff daily so it is fresh, buy one and use it. Reading a test strip would be easier than looking at the coolant and guessing if it is good, I would think. I went for a flush last year and it was pretty simple. One and done. Flush out the old, bring in the new.
Yes, but if you don’t drive your vehicle and cycle the coolant throughout your engine then the test strip result will be useless.
Kind of like testing the pool chemicals without running the water pump for a few hours.
Yes, but if you don’t drive your vehicle and cycle the coolant throughout your engine then the test strip result will be useless.
Kind of like testing the pool chemicals without running the water pump for a few hours.
Sorry. That was what I meant. Dump the radiator, fill, drive for a bit with the windows down and heater on and then test? I would THINK that if you drive half an hour to work and half an hour home it would be mixed enough?
Even if you can remove all vestiges of the orange coolant when you switch to the old green coolant you will be back on a two year change schedule. My tow vehicle is a 2003 Tahoe that I purchased new. I have changed the coolant every 5 years since then and am still on the original cooling system hoses and hardware. Even the water pump is the original.
Antifreeze
