Ginger7

So, I just picked up a '94 2500 with probably ~500 K on it, and virtually no maintenance done in the last 7 years. Truck started spewing coolant when parked after getting hot, filled it up, drobve it home, now not leaking and still full... I have a pressure tester coming, and plan on replacing what ever needs it. (Thermo, hoses, cap, rad or water pump if necessary). I have seen a few posts speaking to only using HOAT coolant, and I have no idea what people have been putting in this... Finally my question... Should I flush w/ HOAT before working on system, or just do the work and then fill with HOAT coolant?
Thanks guys!
Tim
Ginger is the truck

John_P

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Tim:

Welcome to the website and and congratulations on your "new to you" 94'
Dodge CTD Pickup!

It sounds like you are headed in the right direction on getting the maintenance done on your truck. I would agree that you need to use only the HOAT coolant or coolant from Dodge (Mopar Brand) for your truck. I would also recommend the "Fleetguard Compleat ES Antifreeze" which is made for the Cummins Engines. You are probably going to get some members here that will tell you "any coolant is alright" for your Cummins Engine, but I can tell you from personal experience that IMHO that is not right!

I own a 1996 Dodge CTD 12 valve and my original engine had block pitting which I feel was from the coolant I used in that engine! At about 100,000 miles, I had flushed and changed my coolant and added "Prestone Green Antifreeze" Back then, I didn't know what I know now and it cost me Tim. My block actually had several small "pinholes" that developed behind the pushrod inspection plate, in the blocks cooling ports and was leaking coolant from those cooling passages to the outside of the block and then down to the oil pan. I didn't know it until AFTER the engine was rebuilt and I began seeing coolant in my oil! I ended up having to get a new block and still have the old block in my garage for those that doubt this can happen!

There is a phenomenon in a diesel cooling system called "cavitation erosion" which is too complicated to explain here, but you can Google it and read up on it if you want. There are those that say it CAN'T happen on the Cummins 5.9, but I am proof that it CAN happen!

Anyway,.....not trying to scare you Sir, just to help you NOT make the mistake that I did. Stick with recommended coolant you mentioned or that "Fleetguard" Product I mentioned.

Good luck Sir!

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John_P

Ginger7

Thanks John, I actually do a lot of plumbing and working with caustics (decontaminates) at work, so I am very aware of cavitational errosion, but wouldn't have thought about it happening in my truck. I guess I was thinking more along the lines of the wrong coolant degrading the rad hoses and o-rings than eroding the metal. Point being it sounds like I will flush the system as well as possible with distilled water before doing the work to get out all the old stuff I can, then refilling with a recommended coolant. I'll look into the Fleetguard for sure once I determine where my leak is.
Thanks again!
Tim

06RAM2500

HOAT coolant is required for the 03 to current Cummins engines. It's because too many kinds of metals are in the system, and this helps to prevent corrosion better, especially the block. (remember the old 7.3 IDI's?)

I'd do a full flush, w/ a new water pump, hoses, belt, t-stat, cooling fan, radiator cap, and possibly a new heater core. Probably wouldn't hurt to make sure the fan hub isn't loose, or has a "tight spot" when you spin it.

John_P

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No problem Tim! BTW,......I was not trying to insult your intelligence on that "cavitation erosion" issue. It is something that many diesel truck owners are not aware of. I wanted you to know what had happened on my truck so it did not happen to your truck.

Robert Rausch

Cummins has said that cavitation erosion was not a problem on the 12-valve engines. At least that's what I read back in 2000 in the old TDR magazine that I used to subscribe to (before I found this place!). John, I wonder why your engine had the problem? Any ideas?

John_P

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Robert:

Thanks for your post/reply buddy! It is good to hear from you again.

Your right Robert, TDR did post that in their magazine! I read it too. But my stock Cummins 5.9 12 valve block is proof that something was going on inside that block. In talking with ALOT of experts on this, including a couple Cummins Engineers, I feel it may be because of my use of the "Prestone Green
Anti-Freeze." I have looked at the chemical "breakdown" of the ingredients in the "Fleetguard Compleat ES" Anti-Freeze VS the "Prestone" and the difference is pretty darn amazing. Personally, I will NEVER use anything but the "Fleetguard" Product again! I will try to get some pictures up of the "pin-holes" in my block so you guys can see what I am talking about.

Take care Robert.

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John_P

Ginger7

Hi all, thanks for the help! After pressure testing, found the radiator was the culprit, ****** like drunk at 6 PSI. Replaced it, sucked it down, and it held a vacume with no needle creep for a 1/2 hour so filled it back up (std. Ethylene Glycol 50:50) and all appears to be well! (with the cooling system anyway) Thanks for the help!
Tim

joem

oh crap, I flushed my new to me but old 1995 a year ago and used prestone green plus a bottle of the powerstroke anti cavitation stuff just in case... now im looseing about a quart of coolant every 200 miles. nothing on the ground, nothing in the oil and nothing in the passanger floor.... no bubbles with the cap off at idle either- any ideas?

John_P

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Joem:

Are you sure there is no antifreeze in your oil? On my 1996, I was loosing the antifreeze at a rate a little less than you are seeing. I also could not physically see it and beleive it or not, I could not smell it either.

I ended up getting an oil sample test kit from "Valvoline" and sent my oil to them for anaysis and they found the antifreeze in the oil through that analysis. I would also check your headgasket around the exhaust manifold where the head can leak slightly without you being able to see it due to the fact that the heat dries the antifreeze before it can accumulate or form a drop/puddle on the ground.

joem

the weather has been to poor to get a good look, but im still looseing 1qt per few hundred miles but im not gaining anythig on the dipstick, just the normal 1qt per 5,000 miles loss. God I hope my block isnt toast, the engine is the only thing keeping this trucks title in my name- Mopar stuff is brakeing left and right

taneum

Not to jack this thread but can anyone explain the best way to flush your system to try to get all the old antifreeze out.

elephantrider

i used the peak antifreeze coolant flush kit that you can get at autozone. you splice into one of the heater hoses and run faucet water through the system until it runs clear.

joem

I just fill, run, and drain twice with distilled water. then when adding coolant I just add one gallon of 100% then 50/50 from that point on. works perfectly

joem

John P, still waiting for good weather to check the coolant for leaks, seems to be leaking when sitting- maybe the rad drain? I had trouble with that plastic petcock last summer, wouldnt move more than a 1/4 turn.
I plan to take it to my dads shop, drain the oil out and then put a bucket under the open oil pan- let it sit for a week strait with the drain plug removed to see if I get any water out of the oil pan?