Changing Coolant- 2008 Z51
Le Mans Master
Joined: Oct 2006
Posts: 5,078
Likes: 19
From: Cumming, GA
Odd how different folks have different experiences with the same product. I have had zero issues with green in all the cars I have owned and have owned 3 GM products in which the Dexcool began to turn to mud. Again, to each their own.
It cost less than $10 to drain and refill green so no worries.
Melting Slicks
Joined: Oct 2009
Posts: 2,173
Likes: 20
From: Chamblee Ga
I suppose you can keep the pink stuff if you change it out periodically.
Racer
Joined: Sep 2005
Posts: 279
Likes: 1
From: montrose colorado
Hi all,
I changed out my coolant to the green stuff also. The dex-cool was building up a layer of brown stuff in the fill tank.
About the refill process, I have drained and refilled several times due to rad changes, water pump or thermostat changes. I always have trouble getting the thing to take all the water. After heat cycling the engine several times over a hour it will, all at once, take the coolant. I believe it was air-locked somehow. It would only take about 1/2 of the quanity that was removed, so I knew it was very short on the fill.
I have had several cam changes done by shops and I watched the whole thing, they dont seem to have any problem with air lock when filling the coolant system.
The last time I did the drain and fill I removed the small return hose at the fill tank. I comes from the head vents I think. Guess what no air lock problem.
I changed out my coolant to the green stuff also. The dex-cool was building up a layer of brown stuff in the fill tank.
About the refill process, I have drained and refilled several times due to rad changes, water pump or thermostat changes. I always have trouble getting the thing to take all the water. After heat cycling the engine several times over a hour it will, all at once, take the coolant. I believe it was air-locked somehow. It would only take about 1/2 of the quanity that was removed, so I knew it was very short on the fill.
I have had several cam changes done by shops and I watched the whole thing, they dont seem to have any problem with air lock when filling the coolant system.
The last time I did the drain and fill I removed the small return hose at the fill tank. I comes from the head vents I think. Guess what no air lock problem.
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
I thought the dexcool was orange? but it does get crusty.
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
[QUOTE=VET4LES;1572405740]
Same here my car is a 2005 with 33,000 miles on it but the color on it is not red. It's orange and crusty looking.
Should I change it?
I would not change the coolant. I can not think of one reason why unless you are close to 100,000 miles.[/QUOTE]
What about the statement in the manual to change it a 5 years or 150,000 miles. I have 23,000 miles and am planning on changing it at 5 years. Is that a waste?
What about the statement in the manual to change it a 5 years or 150,000 miles. I have 23,000 miles and am planning on changing it at 5 years. Is that a waste?
Same here my car is a 2005 with 33,000 miles on it but the color on it is not red. It's orange and crusty looking.Should I change it?
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
I absolutely second this. I have run Dexcool in all of the cars I routinely service since the 1996-1997 timeframe including many GMs, a couple of Toyotas and a Ford ('91 5.0L Mustang). I always mix the Dexcool with deionized water and the cooling systems are always kept properly filled. I've never had a problem with any sludge forming and the Dexcool remains crystal clear after 5 years. Interestingly, I originally made the move to Dexcool when I changed the coolant in two of my cars using the green stuff and the silicate package precipitated out in both cars within a couple of weeks thus requiring replacement (coolant was full of silicate floaties).
I thought Dexcool was a product only to be used in Chevrolet and Toyota?
Le Mans Master
Joined: Jan 2005
Posts: 5,611
Likes: 5
From: Thousand Oaks California
[QUOTE=VET4LES;1572405740]
I would change/flush the Dexcool coolant every 5 years or every 100,000 to 150,000 miles, which ever occurs first. For most of us, the 5 year time limit will occur way before the mileage limit, so the mileage is usually not the limiting factor..
Mr. RedZR has a 2008 MY, so it can not be 5 years old, but I do not know the mileage.
I would not change the coolant. I can not think of one reason why unless you are close to 100,000 miles.QUOTE]
What about the statement in the manual to change it a 5 years or 150,000 miles. I have 23,000 miles and am planning on changing it at 5 years. Is that a waste?
What about the statement in the manual to change it a 5 years or 150,000 miles. I have 23,000 miles and am planning on changing it at 5 years. Is that a waste?
Mr. RedZR has a 2008 MY, so it can not be 5 years old, but I do not know the mileage.
Last edited by calemasters; Dec 14, 2009 at 10:24 PM.
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Team Owner
Joined: Oct 2004
Posts: 27,420
Likes: 64
From: San Clemente CA
[QUOTE=calemasters;1572431716]
I would change/flush the Dexcool coolant every 5 years or every 100,000 to 150,000 miles, which ever occurs first. For most of us, the 5 year time limit will occur way before the mileage limit, so the mileage is usually not the limiting factor..
Mr. RedZR has a 2008 MY, so it can not be 5 years old, but I do not know the mileage.
Thanks. I'm changing it in April. 
I would change/flush the Dexcool coolant every 5 years or every 100,000 to 150,000 miles, which ever occurs first. For most of us, the 5 year time limit will occur way before the mileage limit, so the mileage is usually not the limiting factor..
Mr. RedZR has a 2008 MY, so it can not be 5 years old, but I do not know the mileage.
Instructor
Joined: Dec 2005
Posts: 225
Likes: 3
From: Shelburne Vermont
Mine is a late 2005 C6 with 30,000 miles. I have only put in a new thermostat and one bottle of water wetter. I just drained mine and removed the tank. Orange rusty water. I ran the hose with a flush kit with engine running until clear. NOW, about the tan mud in the res tank. Now let me tell you about the mud. I used radiator flush, and it never even touched it. I then tried lime-a-way, nothing. Tried CLR, nothing. Every chemical in the house and it remained. Don't do what I did, but I had to put in muriatic acid to dissolve it. Don't let this acid touch the radiator cap. I have refilled with Dexcool and will drain next fall. All I can say is this is some nasty mud that looks like tan grout. Now, both of my OLDER GM vehicles are as pink as the day they were made. Go figure...
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
Mine is a late 2005 C6 with 30,000 miles. I have only put in a new thermostat and one bottle of water wetter. I just drained mine and removed the tank. Orange rusty water. I ran the hose with a flush kit with engine running until clear. NOW, about the tan mud in the res tank. Now let me tell you about the mud. I used radiator flush, and it never even touched it. I then tried lime-a-way, nothing. Tried CLR, nothing. Every chemical in the house and it remained. Don't do what I did, but I had to put in muriatic acid to dissolve it. Don't let this acid touch the radiator cap. I have refilled with Dexcool and will drain next fall. All I can say is this is some nasty mud that looks like tan grout. Now, both of my OLDER GM vehicles are as pink as the day they were made. Go figure...
Racer
Joined: Apr 2006
Posts: 486
Likes: 2
From: The Villages FL
LS WON The corrosion inhibitor package in coolant is a witches brew. I am not so sure that contaminating the system with water wetter is advisable. I'm not a chemist so I do not know what reactions can occurr when suppliments are added to the system. From what I have read thus far on this subject, no one has provided a chemical analysis of the rust colored sludge. I am guessing it has an iron content.
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
LS WON The corrosion inhibitor package in coolant is a witches brew. I am not so sure that contaminating the system with water wetter is advisable. I'm not a chemist so I do not know what reactions can occurr when suppliments are added to the system. From what I have read thus far on this subject, no one has provided a chemical analysis of the rust colored sludge. I am guessing it has an iron content.
On this 2005 Corvette I have kept everything factory including the power steering fluid. No experiments on this car.
Intermediate
Joined: Dec 2008
Posts: 46
Likes: 0
Can never overdo maintenance items. I would also change the thermostat to a 160 degree and the hoses at the same time. Dexcool and distilled (not purified, spring or tap water). Heater hoses if you must. Might as well do it right so it lasts another 5 years.
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
Safety Car
Joined: Feb 2008
Posts: 3,712
Likes: 3
From: TEXOMA
St. Jude Donor '08-'09
"fix it till its broken" is what i always say!
p.s. i changed out my coolant this year in my 06 at 35000 miles, but it was because i had to move some coolant lines around when installing the supercharger
-carl
p.s. i changed out my coolant this year in my 06 at 35000 miles, but it was because i had to move some coolant lines around when installing the supercharger
-carl
Instructor
Joined: Dec 2005
Posts: 225
Likes: 3
From: Shelburne Vermont
