02' Coolant change question
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Joined: Oct 2014
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From: Pacific Beach California
02' Coolant change question
Planning a coolant change on my 02' C5 with 75k miles. Been thru the posts on procedure. Will probably do a simple drain and fill. Not clear on filling the system.
1 gallon of pure Dex Cool and the rest distilled water?
2 gallons of 50/50 Dex Cool and the rest distilled water?
What will give me the best mixture?
Car is in Sothern CA, frequent trips to Phoenix.
Thanks to all - Glenn in San Diego.
1 gallon of pure Dex Cool and the rest distilled water?
2 gallons of 50/50 Dex Cool and the rest distilled water?
What will give me the best mixture?
Car is in Sothern CA, frequent trips to Phoenix.
Thanks to all - Glenn in San Diego.
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,440
Likes: 2,184
From: Buffalo Texas
COOLING SYSTEM BLEEDING
1. Fill system through radiator surge tank opening up to base of fill neck. Start engine and idle
for one minute. Install radiator surge tank cap. Cycle RPM from idle to 3000 in 30 second
intervals until engine coolant reaches 210°F (99°C). Shut off engine.
2. Loosen radiator surge tank cap. After all hissing stops, remove cap. Start engine. Idle engine
for one minute and fill surge tank to between FULL COLD and FULL HOT. Install radiator
surge tank cap. Cycle RPM from idle to 3000 in 30 second intervals until engine coolant
reaches 210°F (99°C). Shut off engine. Top off coolant as necessary.
1. Fill system through radiator surge tank opening up to base of fill neck. Start engine and idle
for one minute. Install radiator surge tank cap. Cycle RPM from idle to 3000 in 30 second
intervals until engine coolant reaches 210°F (99°C). Shut off engine.
2. Loosen radiator surge tank cap. After all hissing stops, remove cap. Start engine. Idle engine
for one minute and fill surge tank to between FULL COLD and FULL HOT. Install radiator
surge tank cap. Cycle RPM from idle to 3000 in 30 second intervals until engine coolant
reaches 210°F (99°C). Shut off engine. Top off coolant as necessary.
Le Mans Master
Joined: Sep 2013
Posts: 8,900
Likes: 1,074
From: Wisconsin
When you drain the cooling system on the C5 you get only about 50% (6 to 7 quarts of the approximately 12.5 quart system capacity) of the coolant out of the system. The other 50% is still in the block and cannot easily be removed because there are no block drains. You therefore have about 50% of the old coolant still in the system in a 50/50 mix. So what you would want to do is fill the system with a fresh 50/50 mix to retain an overall 50/50 mix.
On the other hand you can flush the system multiple times with distilled water so that what remains in the block is nearly 100% distilled water. In that case you would want to add about 6 quarts of full strength coolant to get approximately an overall 50/50 mix. (6 quarts of distilled water in the block plus 6 quarts of full strength coolant yields an approximate 50 /50 overall mix) Then top off the coolant with a 50/50 mix to retain an approximate overall 50/50 mix.
On the other hand you can flush the system multiple times with distilled water so that what remains in the block is nearly 100% distilled water. In that case you would want to add about 6 quarts of full strength coolant to get approximately an overall 50/50 mix. (6 quarts of distilled water in the block plus 6 quarts of full strength coolant yields an approximate 50 /50 overall mix) Then top off the coolant with a 50/50 mix to retain an approximate overall 50/50 mix.
Le Mans Master
Joined: Sep 2013
Posts: 8,900
Likes: 1,074
From: Wisconsin
How do you know the temps never get close to freezing?
There are some relatively high altitudes that must be passed through between SD and Phoenix. In winter those altitudes can easily be freezing or below and at speed the air passing through the radiator can produce very cold temps capable of freezing and well below. If it were my car I wouldn't take the chance. I run a 50/50 mix all year and I live in the part of Az that gets to 110+ in the summer. But it also gets a few winter nights that are in the 20's. YMMV.
There are some relatively high altitudes that must be passed through between SD and Phoenix. In winter those altitudes can easily be freezing or below and at speed the air passing through the radiator can produce very cold temps capable of freezing and well below. If it were my car I wouldn't take the chance. I run a 50/50 mix all year and I live in the part of Az that gets to 110+ in the summer. But it also gets a few winter nights that are in the 20's. YMMV.
Manufacturer's recommendation:
The standard recommendation is to use a 50/50 mix of antifreeze and water. This represents a compromise between cooling efficiency and the ability to prevent the mix from freezing during cold weather. After all, the initial purpose of antifreeze is to prevent freezing.
But a 50/50 mix does not give the best cooling. For improved cooling in hot weather, we should use less antifreeze and more water, perhaps going to a 25/75 or a 20/80 mix ratio.
Everyone knows antifreeze prevents corrosion, and corrosion is bad. True enough. But, even a 10/90 ratio of antifreeze to water will serve the puproses of inhibiting corrosion, at least according to one source of information.
The standard recommendation is to use a 50/50 mix of antifreeze and water. This represents a compromise between cooling efficiency and the ability to prevent the mix from freezing during cold weather. After all, the initial purpose of antifreeze is to prevent freezing.
But a 50/50 mix does not give the best cooling. For improved cooling in hot weather, we should use less antifreeze and more water, perhaps going to a 25/75 or a 20/80 mix ratio.
Everyone knows antifreeze prevents corrosion, and corrosion is bad. True enough. But, even a 10/90 ratio of antifreeze to water will serve the puproses of inhibiting corrosion, at least according to one source of information.
Last edited by JR-01; Jan 30, 2017 at 11:31 AM.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The factory Dex coolant fill is a 50/50 mix and GM tested the C5 (and the C4's) cooling system in very hot and very cold conditions. You can get pre-mixed Dex in gallon jugs and that makes it easy to do the drain/fill process.
Get a couple of the pre-mix gallon jugs and you will be fine.
Get a couple of the pre-mix gallon jugs and you will be fine.
Le Mans Master
Joined: Sep 2013
Posts: 8,900
Likes: 1,074
From: Wisconsin
50/50 was an industry wide compromise to handle all climates.
Team Owner
Joined: Sep 2002
Posts: 30,350
Likes: 4,581
From: Bonita Springs, Florida
The factory Dex coolant fill is a 50/50 mix and GM tested the C5 (and the C4's) cooling system in very hot and very cold conditions. You can get pre-mixed Dex in gallon jugs and that makes it easy to do the drain/fill process.
Get a couple of the pre-mix gallon jugs and you will be fine.
Get a couple of the pre-mix gallon jugs and you will be fine.
I use 2 gallons of pre-mixed 50/50 Prestone Dexcool. No hassle.
http://www.iammoon.com/c5tech/coolant_drain.htm
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From: Dear Karma, I have a list of people you missed.
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I run 65/35 distilled/Dex with one bottle of water-wetter in a 17 qt system with Dewitts radiator.
Drifting
Joined: Nov 2011
Posts: 1,401
Likes: 141
From: Summerville South Carolina
COOLING SYSTEM BLEEDING
1. Fill system through radiator surge tank opening up to base of fill neck. Start engine and idle
for one minute. Install radiator surge tank cap. Cycle RPM from idle to 3000 in 30 second
intervals until engine coolant reaches 210°F (99°C). Shut off engine.
2. Loosen radiator surge tank cap. After all hissing stops, remove cap. Start engine. Idle engine
for one minute and fill surge tank to between FULL COLD and FULL HOT. Install radiator
surge tank cap. Cycle RPM from idle to 3000 in 30 second intervals until engine coolant
reaches 210°F (99°C). Shut off engine. Top off coolant as necessary.
1. Fill system through radiator surge tank opening up to base of fill neck. Start engine and idle
for one minute. Install radiator surge tank cap. Cycle RPM from idle to 3000 in 30 second
intervals until engine coolant reaches 210°F (99°C). Shut off engine.
2. Loosen radiator surge tank cap. After all hissing stops, remove cap. Start engine. Idle engine
for one minute and fill surge tank to between FULL COLD and FULL HOT. Install radiator
surge tank cap. Cycle RPM from idle to 3000 in 30 second intervals until engine coolant
reaches 210°F (99°C). Shut off engine. Top off coolant as necessary.
Dave
Drifting
Joined: Nov 2011
Posts: 1,401
Likes: 141
From: Summerville South Carolina
