Flushing Coolant

jarrett88

jarrett88

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Pretty much a basic question, flushing coolant, how do I do it, and does anyone have a diagram or anything for it.
 
What year is your car? Gen 1 is going to be slightly different from gen 2.
 
Judging by the profile, Gen. I. Didn't realize there was a difference. :/
 
The tech article is for Gen I, so that's good.
The LS cooling system is somewhat complicated, so it can be difficult to truly flush the entire system. Those flush kits with the hose connection are worthless for this setup. If the coolant is in really bad shape, then my plan of attack would be disconnect the rad hoses, open the block drains, and pull the hoses off the DCCV. Might have to suction the coolant out of the degas bottle. Then reconnect, start refilling, and be absolutely sure to follow the fill/bleed procedure. This is not the normal "fill and burp" kind of system.
 
These are not the proceedures for flushing the system. If you read that material it will tell you that opening the radiator and vents of the system will only allow you to remove approximately 20% of the entire system's coolant. You need some kind of special equipment if you want to flush the entire system...
 
Elemino said:
These are not the proceedures for flushing the system. If you read that material it will tell you that opening the radiator and vents of the system will only allow you to remove approximately 20% of the entire system's coolant. You need some kind of special equipment if you want to flush the entire system...
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It's more than 20% (a little over 50% as I recall), but you are right. If you want or need a good full flush, it would be best to go to the dealer.
 
joegr said:
It's more than 20% (a little over 50% as I recall), but you are right. If you want or need a good full flush, it would be best to go to the dealer.
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It's worse than you think...

From the gen II procedure link posted above:

NOTE: Less than 80% of coolant can be recovered with the engine in the vehicle. Dirty, rusty or contaminated coolant requires replacement.
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Either way, it means you should visit a shop if it needs replacing. The guy at Autozone looked at me crazy when I asked him where I could dispose of my old radiator fluid when doing the thermostat and DCCV repair. He said "most people just reuse it." It made me think I need to find a better store with better people to talk to...
 
It's like a used condom, totally acceptable to use again.

NOTE: Less than 80% of coolant can be recovered with the engine in the vehicle. Dirty, rusty or contaminated coolant requires replacement.

Stupid question, the wording of this makes it read that you need to remove the engine to completely flush the fluid? Serious?
 
What I am going by is this.

The gen 2 V8 is spec'd as taking three gallons for the cooling system. When I drained the system and replaced the cracked plastic parts, it took about two gallons to refill it. This was on my 04. I'll be doing this on my 06 this weekend.

I think that this fits with the "less than 80%" statement. 50 or 60% is still less than 80%. You are looking at that statement as some how meaning that you are only getting 20% out, but they are saying that over 20% isn't changed. You flipped it around somehow.
 
Thanks for the procedure Joe, sometimes I forget that I have that link saved. :/

Mine was only to get it so I can drive it to and from work for a couple days to get it flushed out completely.
 
jjcool00 said:
It's like a used condom, totally acceptable to use again.
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THERE'S an internet quote that will come back to, ahem, bite you in the end.

jjcool00 said:
NOTE: Less than 80% of coolant can be recovered with the engine in the vehicle. Dirty, rusty or contaminated coolant requires replacement.

Stupid question, the wording of this makes it read that you need to remove the engine to completely flush the fluid? Serious?
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That's actually not strange. Blocks tend to hold a lot of coolant in crevices and the drains are not at the actual bottom of the cooling jackets, so the engine has to be tilted quite a bit or turned upside down to get it all out. It's really fun with tearing down an old engine. You'll fine all kinds of stuff burried in there.
That's why the standard flush procedure is drain, fill with water and cleaner, run, drain, fill with water, run, drain, fill with water and antifreeze. For the LS, I'm more concerned about the heater core, degas bottle, and associated plumbing.
 
Elemino said:
The guy at Autozone looked at me crazy when I asked him where I could dispose of my old radiator fluid when doing the thermostat and DCCV repair. He said "most people just reuse it." It made me think I need to find a better store with better people to talk to...
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The only good option I've seen is to bottle it and call household hazardous waste for a pickup. They've gotten to know me through many gallons of Chem Dip over the years.

And if you think that clerk was crazy, just head down to the pick'n'pull. You can get coolant from a wrecked car for $5 per gallon! Some of it is even green.
 
oddball said:
The only good option I've seen is to bottle it and call household hazardous waste for a pickup. They've gotten to know me through many gallons of Chem Dip over the years.

And if you think that clerk was crazy, just head down to the pick'n'pull. You can get coolant from a wrecked car for $5 per gallon! Some of it is even green.
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OMG... I don't hate my LS. lol

I used brand new Prestone (bought the good stuff) and mixed it with distilled water. I plan to keep this car until the wheels fall off or the engine falls out. So I'm not going to use the radiator fluid that dripped all over everything on its way down to my pan. These guys must be used to ppl that drive crap and don't care if they use crap.
 
My city has a recycling center that takes oil and coolant and stuff. You might try calling city hall wherever you are and ask them if they have a recycling center. Or, if you don't mind being sneaky make a 3AM stop by your local Jiffy Lube. If you feel bad about being sneaky tape a 10 dollar bill to it. If you have a crappy neighbor that you want to screw with, start disposing of it intermittently, half a quart at a time, under their car.
 
When I did it I honestly just ran the engine at temp and let coolant spew out of the radiator drain cock while filling the engine fill with water only. This is after I got it to operating temp and drained first. After you get that bit out and recovered the rest is a pretty weak mix when diluted with water. I have a gravel driveway, so I let it drain after I recovered the first couple of gallons.
 
I did not use distilled water, and years later when I replaced water pump and plastic cooling system parts I did not have any noticable corrosion.
 
scjmc said:
I did not use distilled water, and years later when I replaced water pump and plastic cooling system parts I did not have any noticable corrosion.
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The problem with non-distilled water is that it varies from source to source. Some of it is pretty pure (perhaps yours was) and some of it is pretty bad.
 
Our tap water here is very hard (boiling a gallon of water leaves a white residue in your pots)... My old town car had corrosion caked on from years of tap water poured in it. I used some chemical (RMI25) to clean it up. Distilled water is not expensive by any means, so I see no reason why not to use it.
 
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