Coolant change question
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
On a conventional coolant system with radiator cap it was easy to just run car with water while engine ran until the water came out clear.
Race Director
Joined: Oct 2005
Posts: 14,999
Likes: 200
From: Bay Area Ca.
On a side note the conversation comparing running coolant temps has me scratching my head.
The thing is rpm plays a role here in controlling the water pump speed.
If I run say above 2200 rpm my coolant will be 189* if I run at 1800 it will be closer to 196-198*. This is with a 180* stat.
So comparing coolant * temps is really not applicable if the same rpm hasn't been run.
The temps I quoted are just off the top of my head but would prove to be close enough for my point.
Not everybody drives the same especially with the manual transmission.
I tend to like lower rpms so my coolant temp will be a little higher than if I ran higher rpms.
I have 4:10 gears too.
So 1800 rpm is about 70 mph in 6th. I usually shift around 2000-25000 rpm. And my coolant temps run 192-196 usually when moving, with the 180* stat. They can and will vary with higher and lower rpm use. 189-198* while driving depending.
The thing is rpm plays a role here in controlling the water pump speed.
If I run say above 2200 rpm my coolant will be 189* if I run at 1800 it will be closer to 196-198*. This is with a 180* stat.
So comparing coolant * temps is really not applicable if the same rpm hasn't been run.
The temps I quoted are just off the top of my head but would prove to be close enough for my point.
Not everybody drives the same especially with the manual transmission.
I tend to like lower rpms so my coolant temp will be a little higher than if I ran higher rpms.
I have 4:10 gears too.
So 1800 rpm is about 70 mph in 6th. I usually shift around 2000-25000 rpm. And my coolant temps run 192-196 usually when moving, with the 180* stat. They can and will vary with higher and lower rpm use. 189-198* while driving depending.
Drifting
Joined: Mar 2011
Posts: 1,693
Likes: 144
From: on Barnegat Bay Joisey
After all the flushing and filling in this thread I would like to suggest a simple alternative told to me by an old shade tree mechanic. Every 2-3 years just drain the radiator and refill with new anti freeze solution. Forget the block and heater core. This refreshes the additives which used to be important to keep the water pump seals from failing and destroying the pump bearings. It also kept the acidity in check. Only took a few minutes and maintained the quality of the coolant. Just my .02C
Melting Slicks
Joined: Jan 2001
Posts: 2,016
Likes: 31
From: Little Egg Harbor N.J.
Considering flushing the cooling system and replacing the thermostat on my 1969 small block. I see some recommend drain, fill with water, run the engine and drain again; repeat process until clear water comes out when drained.
My question is what are you doing with the liquids that are gathered during the drain process? The steps seem simple enough, and I want to handle this maintenance myself to save some money but, I want to make sure I am catching and disposing of these fluids properly.
Thanks
My question is what are you doing with the liquids that are gathered during the drain process? The steps seem simple enough, and I want to handle this maintenance myself to save some money but, I want to make sure I am catching and disposing of these fluids properly.
Thanks
Drifting
Joined: Sep 2007
Posts: 1,331
Likes: 148
From: 1000 Islands Ontario
Considering flushing the cooling system and replacing the thermostat on my 1969 small block. I see some recommend drain, fill with water, run the engine and drain again; repeat process until clear water comes out when drained.
My question is what are you doing with the liquids that are gathered during the drain process? The steps seem simple enough, and I want to handle this maintenance myself to save some money but, I want to make sure I am catching and disposing of these fluids properly.
Thanks
My question is what are you doing with the liquids that are gathered during the drain process? The steps seem simple enough, and I want to handle this maintenance myself to save some money but, I want to make sure I am catching and disposing of these fluids properly.
Thanks
M...
Le Mans Master
Joined: Jan 2008
Posts: 6,457
Likes: 297
From: corpus christi Texas
Question: On the cars that I've had & the Toyota i have have now the upper rad hose goes to the stat housing.On the vette the upper rad hose goes to the water pump & the lower rad hose goes to the stat housing? I think i know why,but maybe someone will come up with the correct ansewer....
Drifting
Joined: Nov 2008
Posts: 1,307
Likes: 25
From: NY NY
Draining the radiator will yield around 8 to 9 qts which leaves 3 to 4 qts of old coolant in the system (in the heater core, engine block, etc.). If you are OK with leaving 1/3 of the old coolant in there then just drain the radiator and replace what came out with a 50/50 mix and you are done. If not, refill with water, run the engine until the upper radiator hose is hot, allow to cool, drain, repeat until it comes out clear – 2x did it for me. For the final fill, find the total capacity of the cooling system, add 1/2 that amount of straight coolant, then top off with water until full. Keep an eye on it for a few days, most likely you will have to top it off a bit. Pencil in your next coolant change for 2018. It’s not a hard task, for the most part you are standing around waiting for the coolant and beer to drain.
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Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,108
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
Here in the Phoenix area, a 30/70 to 40/60 ratio works better than 50/50 and even though we live in a desert the cost of tap water is cheap.
Drifting
Joined: Feb 2010
Posts: 1,527
Likes: 34
I wouldn't use tap water, even our natural filtered Hawaiian water.
If interested, read this:
http://forums.corvetteforum.com/c6-c...hlight=dewitts
If interested, read this:
http://forums.corvetteforum.com/c6-c...hlight=dewitts
Melting Slicks
Joined: Jun 2007
Posts: 2,673
Likes: 9
From: Upstate New York
1: I like to flush the system with water. When you are done there is about 3 to 4 quarts of water left in the system, if you put in the 50/50 Dexcool premix you are certainly not ending up with a 50/50 ratio when it gets diluted with the water that’s left.
2: Simple economics. A gallon of 50/50 is $12.50. A gallon of pure Dexcool is $14.00 + 1.00 for a gallon of distilled = $15 for 2 gallons of coolant. Would you rather spend $25 for 2 gallons of coolant or $15?
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
I wouldn't use tap water, even our natural filtered Hawaiian water.
If interested, read this:
http://forums.corvetteforum.com/c6-c...hlight=dewitts
If interested, read this:
http://forums.corvetteforum.com/c6-c...hlight=dewitts
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,108
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
One of these days I might change the coolant in my '04 Silverado. I passed the magic 5 year mark more than 5 years ago, where many claim the engine will fail or the radiator will clog with goo.
The radiator/surge tank cap has never been off and I'm not sure I want to do it yet, since it runs cool enough in 110* temps. Maybe I'll check it when I do the next oil change 2 years from now. That might be a good time to look at the OEM brake fluid too, so I'll make a note to do it then.
The radiator/surge tank cap has never been off and I'm not sure I want to do it yet, since it runs cool enough in 110* temps. Maybe I'll check it when I do the next oil change 2 years from now. That might be a good time to look at the OEM brake fluid too, so I'll make a note to do it then.
Drifting
Joined: Feb 2010
Posts: 1,527
Likes: 34
Few manufacturing giants, Toyota, Honda, Ford and Chrysler for example, will not use GM Dexcool. I came across their reasoning and though I use Dexcool, at the very least, I do the 18 gallon distill water flush more frequent than the recommended 5 years. Hopefully I could avoid Dexcool problems other manufacturing giant encountered through research. My believe that spending $18 on distill water + my time is way cheaper than engine damage.
But to each their own.
But to each their own.
Le Mans Master
Joined: Jan 2008
Posts: 6,457
Likes: 297
From: corpus christi Texas
Runs cooler......
Le Mans Master
Joined: Jan 2008
Posts: 6,457
Likes: 297
From: corpus christi Texas
My Toyota manual says to use Demineralized or Distilled water.It is a steel block with a aluminum head & the rad is not aluminum either.(1990 Cressida) I'll go with the Japanese instead of GM...
