COOLANT/CAVITATION/RELATED QUESTIONS

[Max Mini]

Greetings.

I am super confused.

A few years ago I did some research on what coolant was best for my '91 E350 7.3 IDI short bus, and came away with the solid verdict that the basic green stuff was IT. I also came away with the impression that cavitation was not a huge thing in this particular vehicle. I didn't have as many places to look back then, I guess.

Well, I'm having some issues and googling around to see what might be going on and I just decided to look and see what the symptoms of cavitation might be, for kicks. All of sudden every article I see is saying NOT to use the basic green stuff, that you need low silicate coolant, that 7.3 IDIs are especially sensitive to cavitation - more or less the opposite of my previous takeaway. I have been using green antifreeze for 3 years now.

In all this reading I can't seem to find consensus, and the other thing I can't find is any info on WHAT IT FEELS LIKE, what symptoms will be present, with cavitation.

I have read a dozen articles at this point on what cavitation IS and how it happens but still am no closer to understanding what behavior would be present if that were an issue, and, though I know for sure I need coolant, I'm terrified to put any in because now I don't know what kind I'm supposed to use!

Can anybody give me the answers to those two questions, once and for all?

 

[Farmer Rock]

Whether it's green or yellow doesn't really matter as long as it is treated with SCAs. What you read about about green coolant being bad, was most likely referring to non SCA coolant. You can add those same SCA to your coolant and be good to go. I personally use NAPA KOOL, but there is other good additives. As far as yellow vs green coolant, they are both good as long as they are never mixed. If you switch from one to the other, you need to flush it all first. I am running yellow extended life in my trucks with the SCA




Rock

 

[gnathv]

Are you adding sca (supplemental coolant additive) to your coolant and testing with strips? If you have cavitation that has actually eroded the cylinder, there will be tiny pin holes that will weep coolant into the cylinder. This will cause ****** exhaust with an antifreeze smell. You’ll have disappearing coolant from your coolant overflow tank also. It can progress to the point that it will fill a cylinder with coolant causing engine to hydro lock. This is one of those things that can develop over time if coolant system is not maintained and you’re not aware of it until disaster strikes. I have used final charge (red extended life coolant) already has additives and protects for many miles. This is one of the Pandora’s box subjects. I ran the final charge in my idi for 8 years and in my powerstroke for 7 years so far without problems. I’m sure there are those that will disagree. Also I understand your concern. I recently bought a zero turn mower with a water cooled 2 cylinder yanmar diesel. It’s 20 years old and when I asked the guy I bought it from about coolant additives he looked at me blankly. I bought it anyway and it had green coolant in it. I flushed it and changed to red. Only time will tell. Good luck mulling all of this over.

 

[gnathv]

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[Max Mini]

Whether it's green or yellow doesn't really matter as long as it is treated with SCAs. What you read about about green coolant being bad, was most likely referring to non SCA coolant. You can add those same SCA to your coolant and be good to go. I personally use NAPA KOOL, but there is other good additives. As far as yellow vs green coolant, they are both good as long as they are never mixed. If you switch from one to the other, you need to flush it all first. I am running yellow extended life in my trucks with the SCA




Rock

Thank you!

My NAPA store gave me the phone equivalent of a blank stare, said all they ever recommend is old school green for a truck this old, because that's the only thing that existed when the truck was built, and claimed that NAPA KOOL didn't exist even when I gave them the part number. They finally scrounged up a couple of small (1 pint) bottles from the dusty back shelf and are holding them for me. I am sticking with the green for now because I have to drive tomorrow and need to deal with my immediate need, then I'll look at all the options.

Are you adding sca (supplemental coolant additive) to your coolant and testing with strips? If you have cavitation that has actually eroded the cylinder, there will be tiny pin holes that will weep coolant into the cylinder. This will cause ****** exhaust with an antifreeze smell. You’ll have disappearing coolant from your coolant overflow tank also. It can progress to the point that it will fill a cylinder with coolant causing engine to hydro lock. This is one of those things that can develop over time if coolant system is not maintained and you’re not aware of it until disaster strikes. I have used final charge (red extended life coolant) already has additives and protects for many miles. This is one of the Pandora’s box subjects. I ran the final charge in my idi for 8 years and in my powerstroke for 7 years so far without problems. I’m sure there are those that will disagree. Also I understand your concern. I recently bought a zero turn mower with a water cooled 2 cylinder yanmar diesel. It’s 20 years old and when I asked the guy I bought it from about coolant additives he looked at me blankly. I bought it anyway and it had green coolant in it. I flushed it and changed to red. Only time will tell. Good luck mulling all of this over.

I had never heard of SCA additive until yesterday so no, I haven't been doing that. I don't know what testing with strips is. I do (sort of) have disappearing coolant, I say sort of because I have not had a chance to exhaustively look for a leak yet so the reason for it being low might be super obvious once I do. No ****** smell at all. Is there anything else that would be a giveaway? How do I test with strips? Thank you!

 

[gnathv]

I bought my last test strips from NAPA, they’ll probably say I’m lying lol. The strips read the nitrates in your coolant so you know if you need additives or not.

 

[gnathv]

This may help.


Coolant Test Strips are disposable test strips for measuring the concentration level and condition of Anti-Freeze/Anti-Boil coolants used in all types of combustion engines. They effectively test the coolant's concentration as well as the pH level and alkalinity to determine when service of the coolant is necessary.

APPLICATION
Coolant Test Strips are designed for use in all closed cooling systems in automotive, commercial, marine, mining, construction and agricultural machinery that use an Anti-Freeze/Anti-Boil type coolant.

Coolant Test Strips are suitable for use with all types of Anti-Freeze/Anti-Boil coolants including standard and Extended / Long Life coolants whether they contain OAT or Hybrid inhibitor packs.

Coolant Test Strips Coolant Test Strips have 3 indication markers to accurately access the condition of the coolant and to indicate when service of the engine coolant is necessary.

HOW TO USE

1. Collect a coolant sample from the system in a clean suitable container (do not use coolant from the overflow bottle unless radiator is not fitted with a cap).
2. Dip the test strip in the coolant sample for 2 seconds and then shake briskly to remove excess coolant (coolant needs to be below 110° F / 43° C)
3. Wait 40 seconds and compare the end of the pad colour to the freeze/boil protection chart on the side of the bottle.
4. If the first pad colour is between 33% and 50%, no further service is recommended.
5. Compare the colour of the middle pad (RA*) to the Reserve Alkalinity colour chart. If pad colour is between 3.2 and 6.6 the coolant is good. If not proceed to step 3.
6. Compare the pad closest to the strip handle (pH) to pH colour chart. If the pad colour is above 6.5 and below 11, the coolant is OK. If the colour is below 6.5 or above 11 then service is recommended.
7. The colour matching should be concluded within 30 seconds. Times should be followed for colour matching, as too soon or too late, may result in incorrect readings.

*OAT coolants normally have a lower Reserve Alkalinity. Please continue to Step 6

CAUTION: Cooling systems and radiators run under pressure. Hot coolant is hazardous and can cause severe burns. Do not remove the radiator cap from a hot engine. Wait until temperature is under 50°C before removing the radiator cap. Failure to wait, may result in personal injury. Remove radiator cap slowly to release pressure and avoid coolant spray.

 

[71 Highboy]

#3 and #4 are both correct. It doesn't matter as long as you add the SCA which is readily available. My water filter from NAPA has it in it, adds as it passes thru and I add manually after testing with strips between filters. You won't always see it as steam in the exhaust if the pinhole is down low in the cylinder, but above the rings, your cooling system will over pressure some as the cylinder is scavenged by the incoming charge air when the piston is near the bottom of the stroke. It's sometimes very hard to identify the results of cavitation because symptoms vary, depending on severity. Ask me how I know this, 10 engine transplants in about the same number of months later...

 

[Big Bart]

Are you having issues with your engine or just trying to do good maintenance? It is a real issue, so you do want to add SCA or flush out your radiator and add something like the Peak Fleet Charge with SCA.


I use Peak Fleet Charge with SCA. You can get full strength or pre-mixed with water. If you get full strength I suggest mixing with distilled water to avoid corrosion from minerals and chlorine in the water. Nothing wrong with the 50/50 premix either. Per above check periodically with test strips.


If you choose to replace your coolant and flush out the green coolant. I always suggest a new thermostat (Only use a factory Motorcraft one.) and radiator cap. I have seen it time and time again after flushing the radiator and adding new/different coolant. Many thermostats fail days, weeks, or months later. Radiator caps are cheap and good insurance. I buy the ones with the red tab on top that releases the pressure so you can pull them off safely when the radiator is hot.


Although folks have issues with cavitation occasionally it seems like from all the threads, I have read head gaskets and oil cooler seals are much more common/often the issue with coolant in the oil or in the exhaust. I had to replace my oil cooler seals a couple of years ago, I was getting a little bit of coolant in the oil pan a couple of times when I changed the oil. (It did not mix with the oil oddly, just followed the oil out.)


All the best!

 

[Farmer Rock]

#3 and #4 are both correct. It doesn't matter as long as you add the SCA which is readily available. My water filter from NAPA has it in it, adds as it passes thru and I add manually after testing with strips between filters. You won't always see it as steam in the exhaust if the pinhole is down low in the cylinder, but above the rings, your cooling system will over pressure some as the cylinder is scavenged by the incoming charge air when the piston is near the bottom of the stroke. It's sometimes very hard to identify the results of cavitation because symptoms vary, depending on severity. Ask me how I know this, 10 engine transplants in about the same number of months later...

I just gotta ask. 10 engines in 10 months?


Rock

 

[71 Highboy]

I just gotta ask. 10 engines in 10 months?


Rock

2 engines in and out 5 times each. Should not have counted, but I got good at by myself. I thought this was the last time for the original 6.9 to go back in after the machining on the block, but I was WRONG!! It came out once more and the machine shop owned it, and disassembled and sleeved it on one hole for a pinhole they missed when they bored it. I got it back just like you see it, and that was the tenth time.

You must be registered for see images attach

 

[Big Bart]

71 Highboy,

Wow 2 engines each 5 times!!!!

I wish there was an award I could send through Oilburners for that kind of dedication to an old IDI! I would have cut bait after the 5th time, just bought a nice running truck!

I am going to use your case study to remind members about how you have to hang in there and see it through. Once you do you will have a great truck!

Sorry for your plight, it should not be that hard!

Hats off to getting it done!

All the best

 

[Max Mini]

I just gotta ask. 10 engines in 10 months?


Rock

That is EXACTLY what I was going to post!!!!

 

[Max Mini]

Are you having issues with your engine or just trying to do good maintenance?

All the best!

Well, I thought I was having issues with my engine. It turns out, the hose that connects the radiator to the overflow is disconnected.

I posted when the radiator was still too hot to take the cap off, and saw there was literally nothing in the overflow, so I made an assumption that the coolant was low. Now that it's cool, I opened the radiator and it is overfull. As soon as I turned the cover to the overflow bottle I heard the clunk, and looked to find the connector just hanging there. I don't exactly know how to reconnect it but I can't imagine it's too hard!

BUT - Now I know more, and can maintain better!

 

[Max Mini]

This may help.

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Thanks, that's awesome!