Coolant... should I change it?

CuddaWuddaShuda

Founding Member
Mar 5, 2002
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My 2001 GT is almost 3 years old now. So my natural inclination is to change the coolant. However, I am not sure I want to, for several reasons:

1) It's still bright green in the recovery bottle (seems significant).
2) It's not time yet according to Ford (may not mean much).
3) I don't want to introduce air bubbles or "hot spots" into the cooling system.

#3 is the most significant factor. Every time that I, or a friend, changes coolant, the car always seems to take in less than it should. It seems like cooling passages are very convoluted, and air bubbles are inevitable. I think this has been proven by Smokey Yunick among others; there will be air trapped in the system, it is just a matter of how much. I know the Windsor motors (302, 351) are susceptible to this, but I do not know to what extent the Modular motors are.

Related to #3, the more auto maintenance I have done, the more I am inclined to leave things alone unless there is a truly compelling reason not to. In other words, "if it ain't broke, don't fix it."

Any opinions? Has anyone with a 4.6L changed their coolant with positive/negative results?

EDIT: I guess that if the factory doesn't use a special fill procedure, which is different from what the dealership's mechanics would do, then there is no issue. Does anyone know if they do anything special at the factory to avoid trapping air in the system?
 
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The "rule" for changing coolant is around 30k miles. The 4.6 2v is very easy to get air out of the system. After you have drained the radiator, fill at the coolant recovery tank with a 50/50 mix, leave the cap off, start the vehicle and let it idle, put the heat on so you know when the thermostat has opened, top off coolant level once the thermostat opens, take it for a quick drive and check the level again.
 
The recovery bottle that you mention isn't a traditional recovery tank, this system is different in that it is pressurized and is designed to separate any trapped air from the system. Its been used on all V8 Mustangs since 1996, its called a degas system.
 
Ronald Jones said:
The recovery bottle that you mention isn't a traditional recovery tank, this system is different in that it is pressurized and is designed to separate any trapped air from the system. Its been used on all V8 Mustangs since 1996, its called a degas system.

I agree with you its not like a regular recovery tank like on the 5.0s, but to ford they still call it a coolant recovery/overflow tank so that is why I use that terminology.
 
My advice is this, change your coolant every 3 years max regardless of color or mileage. Just because the visible coolant appears green doesnt mean there is no sludge development. To check for sludge, you need to either drain it or use a long screw driver and scrape it agains the lower edges of the plastic tank where you fill up the coolant system. Beleive me, I just changed my brothers and his has some bad sludge development only after 3 years. I recommend using Prestone anti-freeze or motorcraft and at every coolant change, use Prestone coolant cleaner to clean out the system.
 
Coolant Changes

I flush my coolant every year and refill.As a matter of fact next
week I will be changing the coolant for spring/summer.For some
reason if I don't flush and refill the coolant my stang seems to
run hotter so,to prevent your stang from running hot just flush/
refill the coolant early it's worth it!
 
Absolutely you should change it. Your motor has an iron block and aluminum heads. Because they are dissimiliar metals, a galvanic cell is produced. This breaks down the metals and therefore the fluid has to be changed every year. Cheap insurance if you ask me.
 
Related question which might be stupid.

I have a 2000 with under 12000 miles and I want to flush the system. Can I use tap water to flush it or should I do something different to flush the system before I refill.

Thanks!

Paul
 
5.0's 4 ever said:
The "rule" for changing coolant is around 30k miles. The 4.6 2v is very easy to get air out of the system. After you have drained the radiator, fill at the coolant recovery tank with a 50/50 mix, leave the cap off, start the vehicle and let it idle, put the heat on so you know when the thermostat has opened, top off coolant level once the thermostat opens, take it for a quick drive and check the level again.

Thanks a bunch.

00gtblkvert said:
If you think it's still ok then leave it for a bit longer, i would just keep an eye on the temp guage and coolant level. Alot of people knock Ford but they designed the engine - they know more about it than we do.

I absolutely agree that people don't give Ford enough credit for knowing the car. I am among the few people who has ever pointed out the logic behind the selection of the 3.27:1 rear-end ratio. BUT:

1) I don't think watching the temperature gauge will help me. My car always runs with the temperature gauge right at the middle. I think that if the water-based cooling system is degraded, the fan will just run more.

2) Ford has some ulterior motives in writing the maintenance schedule. Many consumers actually compare operating and maintenance expenses between cars. This is especially true among females and among the kind of people who read :notnice:Consumer Reports:notnice:. Now I think it is asinine to try and save money by purchasing a $25,000 car and then putting cheap gas in it and waiting until the last minute to do preventive maintenance. But most people don't think like I do, and will tend to attach much importance to things like octane and maintenance requirements. I read something in the paper recently about a car that was designed completely by/for women, and it had an oil change interval of 31,000 miles. Now that doesn't appeal to me, but apparently someone attaches value to it.

3)Ford relies pretty heavily on fleet sales, and maintenance intervals make a big difference there.

None of this is to contradict the fundamental truth of what you're saying, just to point out that Ford, and other buyers, have much different motivations than I do in selective maintenance intervals.

Sleepy1 said:
Absolutely you should change it. Your motor has an iron block and aluminum heads. Because they are dissimiliar metals, a galvanic cell is produced. This breaks down the metals and therefore the fluid has to be changed every year. Cheap insurance if you ask me.

That is an interesting point. But how does changing the fluid help? It's still a wet cell even with the new fluid, right? Do you mean that the galvanic effect breaks down the fluid faster? Does it result in the accumulation of sludge? What are the long-term effects on the durability of the block/heads? I know Ford uses some really tough head gaskets because of the bimetallic issue... but are there durability issues elsewhere, e.g. the bottom end or the valvetrain?

Incidentally, the head/block materials issue is a surprisingly contentious one... I once made a post where I just happened to mention that some of the world's fastest cars (production and otherwise) had the iron block / aluminum head combination. I got flamed by '96-'01 Cobra owners. But none of them were smart enough to point out that the Al/Iron combo basically creates a battery, which suffers from an ongoing chemical reaction. The posts were more along the lines of "99 k0bra 1$ the most e|eet awesome r0x0r and u r just jelu$. My '99 k0bra [insert your own preposterous and meaningless street racing anecdote here]." So this is not really a topic on which we can hold an intelligent debate:(, but i appreciate your input :) .

Les Paul said:
Related question which might be stupid.

I have a 2000 with under 12000 miles and I want to flush the system. Can I use tap water to flush it or should I do something different to flush the system before I refill.

Thanks!

Paul

Good question... I would be inclined to avoid tap water, which is loaded with minerals and rapidly oxidizes metal. Am I wrong? Bueller? Anyone?
 
i flush my radiator every six months. i drain it, then pour in a gallon of distilled water. close the drain, fill with half prestone, half distilled water. what i do is i measure the amount coming out, and pour that back in. what you can do is leave the radiator cap off, turn on car and squeeze upper radiator hose to help expel air. i drain the block and radiiator every year. its actually easy and ive been told if you flush your radiator every six months, you dont need to use one those harsh chemical flushers. hope this helps. :banana: :flag: :banana:




edit....avoid tap water which like stated can have mineral deposits and other stuff, use distilled water, a tad expensive but worth it on aluminum engines
 
average guy said:
i flush my radiator every six months. i drain it, then pour in a gallon of distilled water. close the drain, fill with half prestone, half distilled water. what i do is i measure the amount coming out, and pour that back in. what you can do is leave the radiator cap off, turn on car and squeeze upper radiator hose to help expel air. i drain the block and radiiator every year. its actually easy and ive been told if you flush your radiator every six months, you dont need to use one those harsh chemical flushers. hope this helps. :banana: :flag: :banana:




edit....avoid tap water which like stated can have mineral deposits and other stuff, use distilled water, a tad expensive but worth it on aluminum engines

every 6 months? that seems rather excessive to me, what is that on average, every six thousand miles?

which me brings me to my next question, can changing your coolant too often affect things detrimentally? because, after all, you exposing the internal system to more air.
 
Alright. I'll tell my method I used

Prestone makes some stuff called "radiator flush". You're suppost to drain the radiator, fill it up with this stuff and water to the full line, then let the motor run till its at normal operating temp. for 10 minutes, then stop the car, let it cool and drain the water/cleaner mixture. This will clean the impurities from your coolant system. If the system is still dirty after this, you'll need the "super flush" which you put into an empty radiator with water and drive it for a few days and let it slowly clean out the system, then, just drain it out, fill it back up with water. Next, start the car up and let the water run through the system to finish breaking loose and cleaning out the rest of the dirt left behind. Finally, drain this water out and fill it with coolant. If you wish, Prestone makes a stuff that is a block treatment. Its synthetic and will combine to the metal surfaces of your coolants system and will prevent varnish and rust build up.

I did this to mine not long ago. My car only had about 19k miles on it and I'll tell you right now, that radiator fluid was dirty as can be.:eek:
 
btolenti said:
how is eveyone disposing of the old coolant and/or cleaner??????

There should be recycling centers in your town that will take care of this for you. The coolant you drop on the driveway or ground, don't worry too much about it. Just hit it with some soapy and spray lots of water at it. It will dillute enough that it should just wash away.