I had to debate on what coolant I was going to use to replace the coolant mess in my Grandma's 1998 3.1L V-6 Chevy Lumina with yesterday. It has 85,000 miles on it. My uncle who doesn't know a lot about cars had been taking the car to a local garage for oil changes and other under the hood maintenance. I happened to think to look under the hood while I was visiting a few days ago. What should have been bright red Dex-Cool coolant was a greenish-brown color. It appeared to me the garage had been topping off the cooling system with old green coolant. Those poor incompetent morons.
I stopped by Wal-Mart and bought 2 jugs of Prestone Dex-Cool and a few jugs of distilled water and Prestone radiator cleaner (the 10 minute stuff).
After draining the radiator, I installed a back-flushing tee to the heater core inlet hose which runs from the heater core to the top of the engine (the outlet hose runs from the heater core to the water pump and you don't want to ever put the back flushing tee on it). The engine coolant drain plug(s) were hard to get to and the lower radiator hose runs directly to the water pump (pure genius on both the plug(s) and lower radiator hose GM... NOT!) so the back flushing tee was the best option.
After hooking the garden hose to the back flushing tee and waiting for water to run out of the radiator, I flushed the engine for about 15 minutes with the engine running and heater turned on hot and hi using city water from the garden hose (NEVER USE WELL WATER) until the water came out nice and clear. I turned the engine off and then turned the water off and let the radiator drain as I removed the garden hose from the back-flushing tee.
After closing the radiator drain plug, I poured in the Prestone cleaner and topped the radiator off with city water from the garden hose. I put the radiator cap back on and ran the engine again for 15 minutes. After turning the engine off, I opened the radiator drain plug to relieve the pressure then removed the radiator cap.
I attached the garden hose back to the back flushing tee and waited until water was running out of the top of the radiator before turning the engine back on again for another 15 minuted to be sure the cleaner was hopefully gone from the cooling system.
I removed the garden hose from the back flushing tee and waited for the radiator to drain. I then closed the radiator drain plug and filled the radiator with distilled water with the bleeder valves open. Once the radiator was full of distilled water, I put the radiator cap back on and started the engine and then waited for fluid to come out of the bleeder valves before closing them. Once normal engine operating temperature was reached, I let the engine run for 15 minutes with the heater on hot and hi. After that, I turned the engine off, opened the drain plug for the radiator to relieve pressure and then took off the radiator cap. I repeated this 2 more times with distilled water.
During the above, I took the overflow tank out and cleaned it out in the bath tub with dish soap and hot water until it looked as close to new and clean as I could possibly make it. Then I rinsed out with cold water and set it outside to dry.
I also kept thinking and thinking if I wanted to use Dex-Cool. The only place in the town where my Grandma lives that has G-05 was the Ford dealership so I ran over there and bought 2 jugs of Ford Premium Gold (G-05) for $25. After returning to the car, I kept debating between the two choices for quite awhile and then decided the heck with it and used the Dex-Cool. I made that decision due to the fact of the warnings under the hood and in the owner's manual to use Dex-Cool only.
So after the last distilled water flush to hopefully dilute the city water so much as it would all be distilled water in the engine block and draining the radiator, I closed the radiator drain plug, installed the cleaned overflow tank, and filled the radiator with the bleeder valves open with the Prestone Dex-Cool. That stuff is a brilliant color of bright red. I also filled the overflow tank to the full cold mark with Dex-Cool. After putting the radiator cap back on, I started the engine once again (always with the heater on hot and hi in all the steps above) until fluid (usually water) came out of the bleeder valves before closing them.
I took the car for a long drive after I put new wiper blades on it (I am a good Grandson) so that the distilled water in the engine block and the Dex-Cool in the radiator and overflow tank would mix to achieve a 50-55 coolant to 45-50 distilled water ratio.
After waiting for the engine to cool, I topped the overflow tank off to the full cold mark again with Dex-Cool. I put some cardboard under the radiator and engine and told Grandma to tell my uncle to be sure there was no drips of any kind on it.
I have to go back this weekend in which I will check everything.
To make the above long-winded story short, I think it is best to stick with what GM recommends and assuming you flush out the cooling system properly and then maintain it after the change you will be fine with Dex-Cool.
At this point in time, I don't think Dex-Cool is faulty. When it first came out, there were problems with both the radiator caps and also the intake gaskets being over-torqued at the factory. There was an advisory sent to GM dealership garages about these and also the intake gasket has been updated to a better one.
I have always been curious what makes a GM vehicle Dex-Cool only. Do they put some kind of chemical into the cooling system at the factory that coats the internal cooling system parts so that using a coolant with silicates would ruin this coating? There are millions of GM vehicles on the road that have not had any problems with Dex-Cool.
I am glad I own a Ford, lol.
I stopped by Wal-Mart and bought 2 jugs of Prestone Dex-Cool and a few jugs of distilled water and Prestone radiator cleaner (the 10 minute stuff).
After draining the radiator, I installed a back-flushing tee to the heater core inlet hose which runs from the heater core to the top of the engine (the outlet hose runs from the heater core to the water pump and you don't want to ever put the back flushing tee on it). The engine coolant drain plug(s) were hard to get to and the lower radiator hose runs directly to the water pump (pure genius on both the plug(s) and lower radiator hose GM... NOT!) so the back flushing tee was the best option.
After hooking the garden hose to the back flushing tee and waiting for water to run out of the radiator, I flushed the engine for about 15 minutes with the engine running and heater turned on hot and hi using city water from the garden hose (NEVER USE WELL WATER) until the water came out nice and clear. I turned the engine off and then turned the water off and let the radiator drain as I removed the garden hose from the back-flushing tee.
After closing the radiator drain plug, I poured in the Prestone cleaner and topped the radiator off with city water from the garden hose. I put the radiator cap back on and ran the engine again for 15 minutes. After turning the engine off, I opened the radiator drain plug to relieve the pressure then removed the radiator cap.
I attached the garden hose back to the back flushing tee and waited until water was running out of the top of the radiator before turning the engine back on again for another 15 minuted to be sure the cleaner was hopefully gone from the cooling system.
I removed the garden hose from the back flushing tee and waited for the radiator to drain. I then closed the radiator drain plug and filled the radiator with distilled water with the bleeder valves open. Once the radiator was full of distilled water, I put the radiator cap back on and started the engine and then waited for fluid to come out of the bleeder valves before closing them. Once normal engine operating temperature was reached, I let the engine run for 15 minutes with the heater on hot and hi. After that, I turned the engine off, opened the drain plug for the radiator to relieve pressure and then took off the radiator cap. I repeated this 2 more times with distilled water.
During the above, I took the overflow tank out and cleaned it out in the bath tub with dish soap and hot water until it looked as close to new and clean as I could possibly make it. Then I rinsed out with cold water and set it outside to dry.
I also kept thinking and thinking if I wanted to use Dex-Cool. The only place in the town where my Grandma lives that has G-05 was the Ford dealership so I ran over there and bought 2 jugs of Ford Premium Gold (G-05) for $25. After returning to the car, I kept debating between the two choices for quite awhile and then decided the heck with it and used the Dex-Cool. I made that decision due to the fact of the warnings under the hood and in the owner's manual to use Dex-Cool only.
So after the last distilled water flush to hopefully dilute the city water so much as it would all be distilled water in the engine block and draining the radiator, I closed the radiator drain plug, installed the cleaned overflow tank, and filled the radiator with the bleeder valves open with the Prestone Dex-Cool. That stuff is a brilliant color of bright red. I also filled the overflow tank to the full cold mark with Dex-Cool. After putting the radiator cap back on, I started the engine once again (always with the heater on hot and hi in all the steps above) until fluid (usually water) came out of the bleeder valves before closing them.
I took the car for a long drive after I put new wiper blades on it (I am a good Grandson) so that the distilled water in the engine block and the Dex-Cool in the radiator and overflow tank would mix to achieve a 50-55 coolant to 45-50 distilled water ratio.
After waiting for the engine to cool, I topped the overflow tank off to the full cold mark again with Dex-Cool. I put some cardboard under the radiator and engine and told Grandma to tell my uncle to be sure there was no drips of any kind on it.
I have to go back this weekend in which I will check everything.
To make the above long-winded story short, I think it is best to stick with what GM recommends and assuming you flush out the cooling system properly and then maintain it after the change you will be fine with Dex-Cool.
At this point in time, I don't think Dex-Cool is faulty. When it first came out, there were problems with both the radiator caps and also the intake gaskets being over-torqued at the factory. There was an advisory sent to GM dealership garages about these and also the intake gasket has been updated to a better one.
I have always been curious what makes a GM vehicle Dex-Cool only. Do they put some kind of chemical into the cooling system at the factory that coats the internal cooling system parts so that using a coolant with silicates would ruin this coating? There are millions of GM vehicles on the road that have not had any problems with Dex-Cool.
I am glad I own a Ford, lol.
