coolant change interval?

titanium10k · Apr 8, 2004

I had to replace my radiator because of a crack in it. well i popped off the top and bottom chambers to see how things looked and i couldnt believe how corroded it was. I always flushed and refilled every 2-3 yrs or 36k miles.
This radiator was in 94 dodge dakota. I have pics but dont have link to post to. If someone wants to post them i can email them to you. For now on gonna flush no longer than every year and half between.....

Amkeer · Apr 8, 2004

Make sure you use DISTILLED water, not tap! Completely flush the system with distilled water only!

Daily Drives:
-2003 Toyota Tacoma PreRunner XtraCab, 2.7 Liter , Mobil1 Synthetic SS 5W-30.
ODO 7950 Miles.
-1995 Toyota 4-Runner 3.0 V6, Mobil1 Synthetic SS 10W-30.
ODO 84300 Miles.
http://community.webshots.com/user/amkeer

tadaima · Apr 9, 2004

For me, I dont drive my car much, but I change it at the 2yr mark regardless of mileage. I have a 2000 camry and I just changed the coolant. The coolant looks great, but only has 10K on it, while in 2002 it had about 20K on it. The fluid looked good back then as well. I looked down the radiator and it looks perfect. I am with some people that change it once a year, but since i used the toyota coolant I expect a little more life on it since you pay like double the price. I would change it more often, but apparently this toyota doesnt do well during bleeding and it seems to overheat doing the process. (not hitting the red but 8/10ths the way). I personally dont feel too good about it, cause i can see the head getting hot while the cooling tubes are empty in there.

Patman · Apr 9, 2004

I don't know how this is possible but my next door neighbor told me he's never changed the coolant in his 1990 3.1L Sunbird! He bought it new, so it's 14 years old now! Believe it or not he now has over 250,000 miles on it, on the original engine and auto trans! He's never had a single problem with either of those, not even the intake problem most 3.1s have. His only issue has been alternators and brakes, he has gone through a lot of those. And the computer on it failed once (but he found a used one for $75) This car just won't die on him! He told me he used 5w30 Mobil 1 or Castrol Syntec at the beginning, but now just uses cheap oil. He used to change it every 3-4k but now he just does it "whenever".

thinshavings · Jun 11, 2004

Distilled water is the key to a corrosion free system.

SteveD2 · Jun 12, 2004

Sorry to hijack, but is it common practice for a shop to use distilled water in the radiator? I know the previous owner of my truck allways had everything changed for him...

Michael Verbick · Jun 12, 2004

I don't know of any shop that uses distilled water. That's why I do everything myself.

Gary Allan · Jun 12, 2004

quote:

I don't know how this is possible but my next door neighbor told me he's never changed the coolant in his 1990 3.1L Sunbird!

..and I think that I've changed mine two or three times (maybe) in my 92 Caravan w/ 160k on it. The rad has been replaced ..but only because of the plastic tank seeping ..not loss of effective cooling or tube degradation.

There has to be some method to this madness that creates problems for some ..that others are conspicously exempt from.

For example ..if you have a "sealed" heating system, where hot water is recirculated. If you set your "chemistry" and don't disturb the system ..you should have no further need for maintenance ..ever. Move that to a "boiler" and other chemical processes take place.

I imagine that there is some correlation to the number of heating and cooling cycles that the engine sees. Most of my vehicles see primarily ALL highway for the first 5 years of service (typically a 25 mile one-way commute). They are then retired to occasional drivers. Hence a mileage/time interval doesn't seem to prove out in my experience. It's only when they are "retired" from primary service do they evidence these types of maintenance problems ..where mileage/time see a radical increase in heating/cooling cycles for the system.

Transitional endothermic reactions that stop much like current flow stops once an expanding magnetic field is done expanding in a conductor(embrace the absract comparitive)???

seotaji · Jun 13, 2004

^

i agree, bring your own.

cousincletus · Jun 15, 2004

A lot depends on the hardness & minerals in your tap water. I always use tap water and never had a problem with it. However, we have good quality water in this part of VA. The reason I drain and refill every year is because of the dissimilar metals in the cooling system. Aluminum head, radiator and cast iron block. Also, I noticed on the bottle of antifreeze (Texaco green stuff) it says that it protects for at least one year. So I figure since I am not getting all the antifreeze out in my drain and fill I will do it once a year to be safe.

yugrus · Apr 25, 2005

quote:

Originally posted by Amkeer:
Make sure you use DISTILLED water, not tap! Completely flush the system with distilled water only!

How do you actually flush with distilled water? You just pour it into radiator? I thought it has to be "flushed" with some kind of pressure?
Would Mr.Clean car wash gadget help if I decide to use tap water for the flush? It has quite a filter in it, but the flow is way too slow.
Where do you put the "flush" water that comes out of radiator? It should not be going into sewage system, right? So do I need multiple containers to store and then dispose of old coolant and flush water?
My manual calls for 30k miles coolant change and I hesitate to let someone do that. I’ve had a bad luck with air bubbles at thermostat in the past, so I’d rather check everything myself.

Is it even nesessary to flush the system in the car of 30k miles and less then two years of age?
Would drain and refill do it?

Thanks a lot!

willkie · Apr 26, 2005

I just changed my fluid on my Honda after 35k miles and 4.5 years and everything was still fine. That was the good news but the Honda extended life costs
$10 a gallon already premixed 50 50. If you mix in
anything different you are back to 2 to 3 years. I did not have to flush so that was nice. The total miles on the car is 150k and it is a 94 model. The biggest problem on the Legend was the plastic top
radator would crack and it could take out the head gasket.

rpn453 · Apr 26, 2005

quote:

Originally posted by Patman:
I don't know how this is possible but my next door neighbor told me he's never changed the coolant in his 1990 3.1L Sunbird! He bought it new, so it's 14 years old now! Believe it or not he now has over 250,000 miles on it, on the original engine and auto trans!

My dad has the same belief. He thinks I'm crazy and hassles me whenever I change coolant. He claims to have never changed coolant in any vehicles, and he had his last Suburban for 19 years!
I just do mine every 50K km for peace of mind, since it's only about $10 and easy to do. And, of course, I use distilled water. No flush, just drain and replace.

widman · Apr 26, 2005

The additive in the green stuff settle out and mix with minerals and should be dumped every year to 18 mo max.
I like the extended life products, like Delo Extended life or some of the HOAT hybrids out there. They are good for 4 or 5 years (or first crash).
Tap water also has chlorine in it. We rinse with tap water, fill with distilled water.

Amkeer · Apr 26, 2005

Best to spend the .54 cents and use distilled to flush any loose deposits out. Any remaining distilled from draining will be fine in the system.

yugrus · Apr 26, 2005

quote:

Originally posted by Amkeer:
Best to spend the .54 cents and use distilled to flush any loose deposits out. Any remaining distilled from draining will be fine in the system.

I understand that. But how do I flush? Do I just pour distilled water from its container into radiator and then drain it? Do I run the engine for a while with distilled water to loose any deposits?

Stinky Peterson · Apr 26, 2005

Drain the coolant and refill with tap water. Open the heater control so it's on hot (not the fan) so water will flush the heater core too. Run with the radiator cap off and watch for flow in the radiator. Let is circulate about 10 minutes after you see flow then drain. Refill and repeat the process about 4 times. Don't put cold water in a hot engine can cause damage from thermal. I'm usually too impatient to wait for the engine to cool so hook a garden hose to the hot-water heater and refill with hot water. For the last rinse use distilled water.

To refill - look up the capacity of your system in the owners manual and then add 1/2 of that amount of antifreeze concentrate. Top off with distilled water. Check to see that you have a 50% mix. This give good boil protection and -34F freeze protection which is good enough for all but arctic conditions.

Good luck!

yugrus · Apr 26, 2005

Thanks everyone!
Now, if I do flush with water, do I just dump it on the driveway or do I collect it as I do with old coolant?

Drew99GT · Apr 27, 2005

quote:

Originally posted by yugrus:
Thanks everyone!
Now, if I do flush with water, do I just dump it on the driveway or do I collect it as I do with old coolant?

I'd retain the initial drain and recycle it, then just let the flush water drain down the driveway. After a complete flushing, it'll highly dillute any remaining coolent. If you know how to take the thermostat out of your engine, Stinky's flush method will go very quickly and you can do it with a cool engine. With the stat in, you have to wait till it opens (when the engine coolent gets to operating temp) to actualy circulate the coolent in the engine block out.

Drew99GT · Apr 29, 2005

quote:

Originally posted by Winston:
I do not see a lot of benefit to flushing. The main reason for changing the coolant is to ensure that you have plenty of corrosion inhibitor. The main problem with stinky's method is that you will have some plain tap water left in your system. I think it is very important to only use distilled water. That is why Honda only sells premix coolant. It is because bad water can cause a lot of problems in your coolant system. Most of the build of of stuff in the radiator is due to mineral deposites from the water. Here is what I do:

Drain and refil with distilled water. Bring car up to operating temp, turn on heater. Drain system again. Fill system with enough coolant to equal 50% of your system capacity. Top up with distilled water.

Your tap water might not be too bad, but it will have some minerals that are bad. Distilled water is better and not too expensive.

Oh, it is really bad to put any antifreeze down the storm drain. Even the flush water. Recycle or put the stuff down the drain in your house. The city water treatment system can handle the small amounts of glycol that they get from homeowners.

If you don't have a block drain (and even IF you do in some cases), your not getting 100% of the old coolent out. If you don't flush and just drain the radiator, you should refill with a premixed solution. If you refill with a full concentrated amount of coolent that's 50% of your system capacity your cooling system will have too much coolent in the mixture.

coolant change interval?

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