MY 99 ext cab 5.4 auto 3.55LS has just hit 101,000 miles. I don't drive it too much but do tow my 4000lb boat with it. This one is gonna have to last me a few more years until I can get my F250 superduty, diesel. Anyway, the radiator/engine temp isn't giving me any problems at all. Should I flush the fluid just as preventative maintenance?

 

YES

 

Absolutely.

 

Thanks. There are a lot of antifreeze choices out there, can you all please recommend one. Also, is water part of the mixture or should I stick to 100% antifreeze and how many gallons will I need?

thanks,,,,

 

I don't have a preference for brand, but whatever you do, do not add 100% antifreeze! You really don't need more than 30% coolant (70% water), unless you live in Alaska, and even then, 30% should be fine.

Coolant (anti-freeze) actually makes the engine run hotter. You really only need it, in small doses, to keep the mixture from freezing, to lubricate the water pump, and to help condition the hoses from the inside. BTW, your old anti-freeze will make an excellent rubber conditioner for your tires and rubber trim. It gives tires that "new" look, rather than the glazed donut look you get with most rubber conditioners.

 

coolant adds not only freeze protection but boilover protection too. I live in florida so the boilover is our main concern here. But not 100 percent coolant anywhere. Just follow the recommendations on the bottle. I stick with prestone because I like name brands. I think they usually recommend 50/50 mixture. Also use distilled water for the mixture, or get the premixed stuff. This keeps the hard water stuff out of your engine.

edit: also dont forget to change the thermostat with the factory recommended replacement. This is very important.

 

"Boilover protection" is a very misleading term. "Coolant" is a very misleading name, as well, considering it makes the engine run hotter. Coolant increases the temperature the fluid will reach before boiling over, but it's hardly protection. You don't want your cooling system to reach 265 degrees, that's where damage occurs. People in Florida particularly would benefit from no more than 15% coolant. If you want a cool running engine, don't put in so much coolant.

 

I run 50/50 mix in the hottest temps and it never goes above my thermostat temp, usually cooler. and my vehicle does alot of Idleing where its the hardest to keep it cool. I dont remember what the premixed stuff is but I thought it was 50/50?

I have tried all different combinations in my modified 85 Mustang gt and 50/50 gives me the best results. Thats just been my experiences. I am shure you could use less. There seems to be less crud in there after years of use with 50/50 mix. (I have had this stang for 15 years so its enough time to do some comparisons).

Like I said before, I would just follow the manufacturers recommendation as there are many variables in vehicles, regions, etc

 

Here is a really good read on the subject.

In 1998, I worked for Bill Elliott (Nascar Cup driver), and was really surprised to learn that the only authorized use for coolant in Nascar is as the fluid used when cc'ing cylinder heads. It's not allowed in the cooling system, but they wouldn't use it anyway because water is the best medium for transferring heat.

Whatever works for you is great! Really. I'm just sharing the fact that the more coolant you use, the more likely you are to damage your engine. Coolant protects from boilover, but you want it to boilover if it gets too hot. Otherwise you'll just go on your merry way, warping your heads.


BTW, if you were selling a product, would you recommend that someone uses it for 50% of the mix, or 25%? You'll double your profits if you say the former.

 

Like all these guys say, run something like 50/50 mix, it's also in the owners manual to run unless your in the extremes or something. Also, add some rad flush a day or so prior to changing and maybe a new stat while your there. It's just cheap insurance for cooling so go for it. I do it all the time, well because I'm on my 3rd rad in 6 years- knock on wood, so I'm use to it.

 

I haven't flushed mine yet. Lazy I guess but that begs the question:
Why am I still on my original radiator in almost 6 years (built 6/2000) and you are on your third with flushes?

I suspect that running the flush for "a day or so prior" instead of the 10 or 20 minutes recommended on the label of most flushes might be contributing to the early demise of your radiators.

 

Ok, I will admit when I am wrong and PKRWUD is right
After doing some research I found the same thing he is saying to be true about less coolant= lower temp.
For some reason it was always the opposite in my stang though
Here is the article I found and it actually is for airplanes but the same concept applies:
http://www.challengers101.com/CoolantMix.html

 

I'm really not trying to be "right" (although I know I come off that way sometimes), I just like to help when I can. Thanks for sharing the info you found!

Take care,
~Chris

 

No man, I did a flush once, with the additive, no problem. Then about a year later, rad took a dirt nap- bad. Like an overheating Nova at a hot summer cruise night. Replaced, flush- no additive as it was new rad, new coolant etc. then a year later, there's that smell again. Took it back and got a new rad under part warranty, 13 months instead of 12, they let it slide. Now that one is cool and have flushed again since when my stat died. No additive there either. So, I've used the flush once and did not see any probs with it, just crappy rads. Hey, my dad went through 13 sets of rear drums and 11 fronts before his pulling went away. ABS problem if I remember, on his 94. Some have issues with just one thing constant. Wierd eh?

 

I agree with your statement. The flush is a chemical and chemicals eat things. You have to flush the radiator a few times afterward with water or use a flushing kit to diliute out as much of the flush chemical as possible.

You could run distilled water in the radiator but anti-freeze also has rust preventatives and lubrication additives in it. The PH of the fluid also changes over time which increases the chances of eating the metal parts of the coolant system. I only flush my radiator with water to dilute out the old antifreeze.

If I were to use a flushing chemical then I would install one of these flushing kits on my vehicle.

http://www.partsplus.com/shared/Mark...CoolingSys.pdf