Coolant Change Out

[Tony T.]

I would like to get a idea of a (proper) way on changing out the coolant. I for one will not have to be doing it anytime soon on the 03 CTD (I hope). But do you think that, they use distilled or demineralized water at the factory when coolant is added (according to the way the manual, says to use when changing out the coolant). Cars, and trucks I had before , when it comes time to change, I just drained the coolant from the radiator in a bucket, and add water from the garden hose to the radiator, then run the vehicle with heater on up to temperature to flush the system (maybe a couple of times). Then drain the water (after vehicle cools) out and perceed with using or (guesstimating) a 50/50 mixture to refill (with in mind there's still water holding in the engine block itself). A mechanic friend of mine, said he never use's the radiator flush you can buy, that he had problems before on different occasions where the heater core started leaking soon after wards. I believe the manual says 7 gallons for the 03. If you use a premixed coolant is'nt there still water trapped in the engine block, and you would not have the right coolant to water ratio. Also view points on the distilled or demineralized water thing. Is that really necessary!

 

[dieselpilot1969]

I used the fleetguard es complete 50/50 premix at around 6. 50 per gallon, demineralized or distilled water is all I would ever use. heater core replacements just plain cost out the ass to fix and I change my coolant every october as it outways the cost and time of repairs imho

 

[Rman]

I have personal experience with the water. I had an old ford truck for many years and since it was old and a beater, I never used distilled water in the radiator. It didn't have an overflow resivoir, it just spilled out on the ground when it got hot. So I constantly added water and coolant to compensate. After a few years of this my radiator was acting funny and the truck overheated often. I decided to change the radiator and bought a new one for 100 bucks.



This solved the problem for a short time but it still was running warmer than it used too. I had a valve spring break shortly after that and had to pull the heads to change it. (Long story, I thought it was a burned valve) When pulling the head i noticed the water jackets were just corroded and crusty and very well, clogged to put it mildly. They were filled with deposits from the hard water that i had been using for many years.



So all it all, they're serious about the water issue. If you want the truck to last forever (ok a really long time) it's adviseable to use distilled water in the radiator. Now if you're looking at selling in 200k miles, I think you'll be just fine using tap water. It's a matter of personal preference. I use distilled on some of my vehicles... on the ones that i want to keep for a while. My wifes car that gets replaced every few years i could care less. I run cheapo motor oil, cheapo everything. Because It will work long enough for what i need it for. After that i don't care.



My vote is to use distilled water because I have seen what happens when you don't... . but mind you this was hundreds of thousands of miles and years of abuse. I hammered that old ford truck and it sure could take a beating.

 

[Alan Reagan]

I agree on the distilled water. Don't put faucet water in batteries or the radiator.



I just did my coolant and went with the Fleetguard Extended Life Premix (600,000 mile coolant). The system holds six gallons but both times I was only able to get four out. So on a seven gallon system, you can probably get five out.



My truck is at 100K so I did hoses, thermostat and the serpentine belt as well.

 

[dieselpilot1969]

I had extra left over from the dodge so I did my nissan frontier 4by with the fleetguard stuff too!

 

[CumminsPower98]

You all might think this is crazy but I run 100% Extended life Prestone in my truck. My cousin is doing the same in his '97 and they do just fine. The fleet of about 15 vehicles I work on have all been running 100% Prestone for probably over 20 years for some of them with zero problems. The reason for this is that there is no chance of corrosion from water and you should see how clean the cooling systems stay on this program. Engines I have taken down for rebuilds are spotless and look brand new inside. I don't know about the '03 trucks but to get all the coolant out of the second gens you either need to park nose down on a real steep hill or jack the back end up as high as you can to level the engine so all the coolant will run out the lower radiator hose since they have no block drain at the back.



Mark

 

[Turbo Tim 1]

Originally posted by CumminsPower98

You all might think this is crazy but I run 100% Extended life Prestone in my truck. Mark

Your right I do but that is your business, here is just a little information from this web page



Anti-freeze

Why a rich mix gives less cooling:



First of all, in this article, we refer to the stuff you buy simply as “antifreeze. ” It comes under many different trade names, and for automotive applications, is usually ethylene glycol. We'll just call it “antifreeze. ”



Now if you've ever poured the stuff into a radiator, you no doubt observed that it is much “syrup-i-er” than water. That is, it has a much higher viscosity. This means that it will not flow as fast through the system as water, and the cooling effect will be less.



Further, the specific heat of antifreeze is less than that of water. This means that for a given temperature change, the antifreeze will carry less heat each time it circulates from engine to radiator and back.



So, if the mix is too rich, the cooling efficiency will be reduced because (1) the flow rate is less, and (2) less heat is transferred per cycle of the coolant.

Another thought provoking paragraph, especially the first line

Coolant temperatures are not indicative of actual metal surface temperatures necessarily.



The metal temperature will have to be significantly higher to produce certain readings depending on the coolant flow rate, metal thickness and media and location of temperature sensing. Head sensing temperatures and intake sensing temperatures can differ greatly by as much as 20 degrees F. Reduced engine compartment airflow at idle or slow speeds reduces the cooling of headers/exhaust manifolds and can greatly increase head sensing readings as such due to heat buildup at the exhaust ports. However, a 250 F degree reading in any case is pause for concern and time to pull off, diagnose the problem and recuperate.

To me this says that metal temperatures will be hotter with 100% anti-freeze at 190 degrees coolant temperature than with a 50/50 mix ratio. Also that if you are using your truck hard you will have a greater chance of boil over. You don't increase your boil over protection over 70% mixture and infact will decrease it. This is in no way a slam on anyone, I am just putting out my semi educated experience

 

[Alan Reagan]

Turbo Tim is correct (or his articles are). Running anti freeze without water is: 1) expensive 2) inefficient. 100% will not protect the engine as well as mixed anti freeze.



The Fleetguard I use is premixed at 50/50 which is the optimum for heat transfer and engine protection.

 

[Straight6Jeff]

When I dumped my coolant at thanksgiving, I had an empty five gallon bucket with a lid on it. Put two holes in the lid to stuff some 3/8 id hose thru it. one hose went to a small vac pump, the other end I stuffed in teh radiator. I pulled about a gallon out of the radiator, then removed the thermostat housing (changing back to the 190 for the winter). I then pulled a total of 4. 8 gallons out of the radiator. The block drains rather well into the lower hose. put the stat back in and filled with the fleetguard pre mix. Took a total of 20 minutes.

 

[rbattelle]

Not to get overly-technical here, but what we're talking about is electrolytes. An electrolyte (such as ethylene glycol) added to water will depress the freezing point 0. 92 degrees F per mole of electrolyte, and raise the freezing point 1. 82 degrees F per mole of electrolyte, up to a 50% mixture, after which you don't gain any additional boiling/freezing margin.



So, if you put 100% ethylene glycol in your engine, then your coolant boiling point is 198*C (388*F) and freezing point is -11. 5*C (11. 3*F).



BUT MOST IMPORTANTLY:

Specific heat is 2. 64 KJ/kg K for EG, for water it's 4. 2 KJ/kg K (higher is better).



That is why you NEVER use 100% ethylene glycol or propylene glycol.



On the other hand, to each his own!

 

[rbattelle]

One more thought

In fact, the best coolant to use would be 100% distilled water. But you can't use that in climates where the ambient temperature gets below 32*F (for obvious reasons). With a well designed cooling system, you could keep from boiling the water.



Addition of electrolytes have the side benefit of allowing the cooling system engineers to be more "sloppy" and inefficient in their designs and get away with it because of the extra boiling margin they get.

 

[rbattelle]

Correction

Well, I'm sorry there was a bit of an error in my previous post. This morning I actually took the time to look up the numbers. Here are the freezing point depression and boiling point elevation figures per mole of electrolyte for water:



Freezing point: 1. 86*C per mole depression

Boiling point: 0. 52*C per mole elevation



So let's compute what the freezing/boiling points are for a 50/50 mix of EG and water in a cooling system of 27 quart total capacity (note: us 3rd gen guys have 27 qt. cooling systems... not sure what the 1st/2nd gen guys have).



The molar mass of EG is 62. 01 g/mol, so the molality of the solution is: 17. 8 mol EG. Without boring you any further with the calculations (which are easy to do... check any chemistry textbook), the results are:



Freezing point: 33. 1*C depressed (91. 6*F)

Boiling point: 9. 3*C elevated (48. 7*F)



So the final boiling and freezing points for a 27-qt. cooling system with a 50/50 mix of water and EG is, roughly:



Freeze: -59. 6*F

Boil: 260. 7*F



For those more chemically-oriented, you will note that I assumed the system is operating at atmospheric pressure, which means the radiator cap was off. Strictly speaking, these figures are only an estimation, since the increased pressure in the cooling system with the radiator cap installed will effect the freeze/boil points.

 

[Rman]

rbattelle I agree with your posts, however running 100% distilled water wouldn't be a good idea. I understand you were being hypothetical and looking at the numbers. But water boils at 210* correct? The operating temp of an engine should be 190-200 degrees. This is OPTIMAL heat condition. I know everyone loves 180 thermostats, but this is for a towing application where the heat generated is generally greater than standard capacity.



Like previously stated actual metal surface temp and water temp are different. Operating the engine at the optimal temp increases life of bearings and practically all moving parts. The clearences and viscosity of the oil are designed as such. Now back to the distilled water issue. Yes the water could be kept at 190* with an efficient cooling system, and since diesels vent more heat to the exhaust because of the compression, I'd be willing to bet the system curently in the truck could perform. HOWEVER, operating this close to the threshold of boiling is dangerous. PLUS, the metal surface temps could boil off water inside the system, produce cavitation effect, and even trap air in the system.



Anyhow, just my thoughts, and ofcourse i undrstand you were looking at it from a more mathematical perspective dealing with specific heat. By the way, the above to paragraphs are pretty much the driving factors in why you mix 50/50 water and EG... running 100% EG is rediculous in my opinion.

 

[Rman]

Re: One more thought

Originally posted by rbattelle

Addition of electrolytes have the side benefit of allowing the cooling system engineers to be more "sloppy" and inefficient in their designs and get away with it because of the extra boiling margin they get.

some call it sloppy, some call it dealing with a budget!!!

 

[Tony T.]

Water

Some pretty impressive replies, but do you think the factory is using the premix coolant, or using distilled water and the HOAT antifreeze mixing it themselves ( which I have not checked with my part's man to see if the Mopar antifreeze is premixed, or not) Or just using the good ol' Mexico water ( I'd hate for my truck to end up with the runs, you know don't drink the water while in Mexico:-laf ). Do any of you change out the factory coolant right away, or wait until maintenance schedule suggest for doing so.

 

[dieselpilot1969]

just my way of doing things but as soon as I feel the truck or any new car I own has had a proper breakin time I change all factory fluids outfor the simple fact I think they use all the cheapest fluids they can get in bulk

 

[Alan Reagan]

The factory uses a premix from what I understand. It's because of the strict requirements placed by Cummins on what will be used (lubricants, coolant). Oil, I run about 500 miles and change. Coolant, I change as directed. They use cheap, I'm sure, but it has to meet Cummins' spec.

 

[rbattelle]

Rhickman,



I agree with you about the 100% distilled water thing. It's just not practical, running so close to the boiling margin. I guess what I meant to imply is that one would be better off running 100% water than 100% EG, if you were going to try something like that. Do you agree?



Also, I didn't mean to be insulting to any automotive engineers out there by saying they could be "sloppy" due to the boiling margin... "sloppy" was just the best word I could think of at the time.



Tony,



I plan to have the local Cummins shop flush my system and replace the coolant with Fleetguard premix EG at the 1 year mark. I do agree with the idea of changing all the factory fluids out, I'm just too lazy to do them all right away. But within 1 year of purchase I will have changed every fluid (except maybe transfer case).

 

[Rman]

well if you were going to try one of the two... both being the wrong thing to do... I'd have to go with the water. Long term effects may be bad though, corrosion and water, lube on the water pump... they're both bad lets leave it at that!



I just got a chuckle out of the sloppy thing, there is always two sides to a coin. I took nothing by it, just found it amusing.