Coolant loss

[RVTRKN]

Its been 20 years since my last Dodge gas engine, so I'm curious if the coolant loss I'm experiencing is normal ? I'm losing 40 ounces of mixed 50/50 distilled water and coolant in 14K miles, seems excessive, but the coolant is clean and no overheating. I did seem to have the fan engage a few times running errands at speeds no higher than 30 MPH, with warm humid ambient temperatures. I saw temperatures of 221*F when I set the parking brake and the fan running, and I shut it off at 2017*F. This seems normal to me, but I'm used to the 5,9 and 6.7 CTD's. I don't want to pay dealer to check system, and then charge me for the service after its found normal. FWIW, I used only the Mopar proper coolant and distilled water. I know the of amount used and the prior level, I set level at 29K miles to the MAX level and it took exactly 40 ounces to put it back to the MAX level at 43K miles. All opinions welcomed.

 

[Jako]

I added 24 ounces, on my 2019 at about 20K miles and 26 months of ownership.

https://5thgenrams.com/community/threads/antifreeze-maintenance.28195/

 

[RVTRKN]

I wish Ram would have left the bottle exposed for an easy glance of the bottle. Using the dipstick is hard to see the level when removed, its difficult to confirm level and takes a couple of times to confirm the level.

 

[Jako]

I wish Ram would have left the bottle exposed for an easy glance of the bottle. Using the dipstick is hard to see the level when removed, its difficult to confirm level and takes a couple of times to confirm the level.

I add a piece of medical tape to the dipstick when I check the level, absorbs the coolant just right and makes it easy to read, been doing it for the past 3 years.

 

[RVTRKN]

Medical tape?

 

[mikeru82]

Its been 20 years since my last Dodge gas engine, so I'm curious if the coolant loss I'm experiencing is normal ? I'm losing 40 ounces of mixed 50/50 distilled water and coolant in 14K miles, seems excessive, but the coolant is clean and no overheating. I did seem to have the fan engage a few times running errands at speeds no higher than 30 MPH, with warm humid ambient temperatures. I saw temperatures of 221*F when I set the parking brake and the fan running, and I shut it off at 2017*F. This seems normal to me, but I'm used to the 5,9 and 6.7 CTD's. I don't want to pay dealer to check system, and then charge me for the service after its found normal. FWIW, I used only the Mopar proper coolant and distilled water. I know the of amount used and the prior level, I set level at 29K miles to the MAX level and it took exactly 40 ounces to put it back to the MAX level at 43K miles. All opinions welcomed.

First off, coolant loss is never considered "normal". It's a sealed system under normal conditions. The only time the system is designed to allow for any loss is when it's overheating.

I'm curious about your method of adding coolant, and why you added coolant to the truck. As well as the history of this truck. Your truck is a 2020, and your join date for the forum was 2020. So I'm assuming you've had this truck since it was new. I'd like to hear more about what was going on to indicate to you that it was low on coolant. You said the truck didn't overheat, so what prompted you to check the coolant level? How often do you check the coolant level? Was the engine hot or cold when you checked coolant level, and was it hot or cold when you added coolant?

As I'm sure you know, the max and min levels aren't just a range. When cold, the coolant level in the recovery tank should be at the min level. It should only be at the max level when the engine is at operating temp. If you added coolant to the max level when the engine was cold you overfilled the coolant. It would then be considered normal for the excess coolant to be pushed out of the recovery bottle the next time the engine reaches operating temp. Then the next time you check the coolant with the engine cool it should by design show at the min level, effectively making it look like the truck is losing coolant.

 

[HSKR R/T]

First off, coolant loss is never considered "normal". It's a sealed system under normal conditions. The only time the system is designed to allow for any loss is when it's overheating.

I'm curious about your method of adding coolant, and why you added coolant to the truck. As well as the history of this truck. Your truck is a 2020, and your join date for the forum was 2020. So I'm assuming you've had this truck since it was new. I'd like to hear more about what was going on to indicate to you that it was low on coolant. You said the truck didn't overheat, so what prompted you to check the coolant level? How often do you check the coolant level? Was the engine hot or cold when you checked coolant level, and was it hot or cold when you added coolant?

As I'm sure you know, the max and min levels aren't just a range. When cold, the coolant level in the recovery tank should be at the min level. It should only be at the max level when the engine is at operating temp. If you added coolant to the max level when the engine was cold you overfilled the coolant. It would then be considered normal for the excess coolant to be pushed out of the recovery bottle the next time the engine reaches operating temp. Then the next time you check the coolant with the engine cool it should by design show at the min level, effectively making it look like the truck is losing coolant.

For starters, coolant level should always be checked hot.

2nd, these aren't sealed systems. The overflow vents to outside. Coolant has water in it. Water evaporates. So you WILL "lose" coolant overtime due to evaporation.

Your overflow bottle should never push any coolant out unless you are overheating and the coolant is boiling. Even if slightly overfilled there is plenty of room for expansion in the reservoir to not dump coolant out. I've had mine overfilled for 6 months, and it's still overfilled. It's not hurting anything, so not going to try and drain any out. It's not like engine oil.

 

[HSKR R/T]

Its been 20 years since my last Dodge gas engine, so I'm curious if the coolant loss I'm experiencing is normal ? I'm losing 40 ounces of mixed 50/50 distilled water and coolant in 14K miles, seems excessive, but the coolant is clean and no overheating. I did seem to have the fan engage a few times running errands at speeds no higher than 30 MPH, with warm humid ambient temperatures. I saw temperatures of 221*F when I set the parking brake and the fan running, and I shut it off at 2017*F. This seems normal to me, but I'm used to the 5,9 and 6.7 CTD's. I don't want to pay dealer to check system, and then charge me for the service after its found normal. FWIW, I used only the Mopar proper coolant and distilled water. I know the of amount used and the prior level, I set level at 29K miles to the MAX level and it took exactly 40 ounces to put it back to the MAX level at 43K miles. All opinions welcomed.

Sounds like you may have a small leak. Some have reported loose fittings in hoses, and a pinhole leak in hose that is hard to track down as it will never drip coolant on the ground

 

[SD Rebel]

Did you check since new and added coolant or did you just notice the tank is low and added since then? Because honestly, I think for many the expansion tank was low since the beginning, most people I've talked with have said their expansion tank level when cold was just above the min mark.

Once topped off, it should be rare that you need to add coolant unless you have a leak somewhere. Though from experience, some vehicle systems just use coolant like BMWs, but I don't suspect the Hemi is that case. However all cooling systems will have some level of evaporation over time. There is a reason why the manual says to check and add coolant without a warning about why it is needed.

I've had my truck for 4 years, and only now did I notice the expansion tank was just above min, it could have been that way since new for all I know.

 

[HSKR R/T]

Did you check since new and added coolant or did you just notice the tank is low and added since then? Because honestly, I think for many the expansion tank was low since the beginning, most people I've talked with have said their expansion tank level when cold was just above the min mark.

Once topped off, it should be rare that you need to add coolant unless you have a leak somewhere. Though from experience, some vehicle systems just use coolant like BMWs, but I don't suspect the Hemi is that case.

I've had my truck for 4 years, and only now did I notice the expansion tank was just above min, it could have been that way since new for all I know.

I have had to add to my reservoir because it wasn't even on the dipstick. That was after three years.

 

[SD Rebel]

I have had to add to my reservoir because it wasn't even on the dipstick. That was after three years.

Mine was at the min mark, I think I added about 4-5 cups, or 32-40 oz to get it near the max mark while hot.

 

[mikeru82]

For starters, coolant level should always be checked hot.

2nd, these aren't sealed systems. The overflow vents to outside. Coolant has water in it. Water evaporates. So you WILL "lose" coolant overtime due to evaporation.

Your overflow bottle should never push any coolant out unless you are overheating and the coolant is boiling. Even if slightly overfilled there is plenty of room for expansion in the reservoir to not dump coolant out. I've had mine overfilled for 6 months, and it's still overfilled. It's not hurting anything, so not going to try and drain any out. It's not like engine oil.

For starters, to use your words, coolant can be checked hot or completely cool, just shouldn't be checked when temps are somewhere in between.

2nd, Yes, coolant has water in it. Contrary to your statement, the system is sealed and under pressure when at operating temps. No water vapors can escape under normal conditions.

Overflow bottle is vented to the atmosphere. It's designed to push coolant out. I agree that it won't push anything out when slightly overfilled. OP says he added 40 ounces. That would be a lot more than slightly overfilled.

The coolant on our 2020 Limited is still showing at the min mark when the engine is cold. I have never added coolant to this truck.

 

[HSKR R/T]

For starters, to use your words, coolant can be checked hot or completely cool, just shouldn't be checked when temps are somewhere in between.

2nd, Yes, coolant has water in it. Contrary to your statement, the system is sealed and under pressure when at operating temps. No water vapors can escape under normal conditions.

Overflow bottle is vented to the atmosphere. It's designed to push coolant out. I agree that it won't push anything out when slightly overfilled. OP says he added 40 ounces. That would be a lot more than slightly overfilled.

The coolant on our 2020 Limited is still showing at the min mark when the engine is cold. I have never added coolant to this truck.

The overflow is not sealed, and will evaporate and vent to atmosphere. This is where you lose "coolant" over time. And with hot coolant expanding into the reservoir while at operating temps, you WILL get some evaporation. That's just what happens when water gets hot. Unless you have figured out a way to bypass the laws of physics.

40oz is not a lot of coolant. That's just over 1 quart and might be 1" on the disptick. Still plenty of empty space in reservoir for expansion without overflowing the reservoir.

 

[Cbty2050]

For starters, coolant level should always be checked hot.

That is incorrect, even the owners manual states to check cold.

 

[Rick3478]

First off, coolant loss is never considered "normal". It's a sealed system under normal conditions.

Not sealed. Regulated.

Allowed to push some out into the reservoir if design pressure is exceeded, then allowed to suck some back in if pressure is below atmospheric when it cools. A little will still evaporate from the reservoir over time. In most cases it's probably time to flush and replace anyway before a significant amount needs to be added.

You could in theory add a diaphragm to the reservoir and make it a true sealed system, but that's probably overkill.

 

[mikeru82]

Not sealed. Regulated.

Allowed to push some out into the reservoir if design pressure is exceeded, then allowed to suck some back in if pressure is below atmospheric when it cools. A little will still evaporate from the reservoir over time. In most cases it's probably time to flush and replace anyway before a significant amount needs to be added.

You could in theory add a diaphragm to the reservoir and make it a true sealed system, but that's probably overkill.

Thanks for the clarification.

 

[RVTRKN]

First off, coolant loss is never considered "normal". It's a sealed system under normal conditions. The only time the system is designed to allow for any loss is when it's overheating.

I'm curious about your method of adding coolant, and why you added coolant to the truck. As well as the history of this truck. Your truck is a 2020, and your join date for the forum was 2020. So I'm assuming you've had this truck since it was new. I'd like to hear more about what was going on to indicate to you that it was low on coolant. You said the truck didn't overheat, so what prompted you to check the coolant level? How often do you check the coolant level? Was the engine hot or cold when you checked coolant level, and was it hot or cold when you added coolant?

As I'm sure you know, the max and min levels aren't just a range. When cold, the coolant level in the recovery tank should be at the min level. It should only be at the max level when the engine is at operating temp. If you added coolant to the max level when the engine was cold you overfilled the coolant. It would then be considered normal for the excess coolant to be pushed out of the recovery bottle the next time the engine reaches operating temp. Then the next time you check the coolant with the engine cool it should by design show at the min level, effectively making it look like the truck is losing coolant.

I'll answer most of your questions, 1st, I bought it used in 2023, at that time I checked the coolant level with a cold engine, and I filled it to the Max level. That was with 29K miles, the level was somewhere in the middle of the range when I bought it, BTW that is per the owners manual, checking it cold. I just drove a 600 mile round trip, and because the temps I reported earlier with fan running, I thought be a good idea to check it. Its not a sealed system, the normal operation of the coolant is, that it expands when hot and any pressure over 16 psi will dump into the reservoir. When it cools, the fluid is pulled back into the radiator as it contracts. You can lose some to evaporation but it should be minimal. You should not lose any fluid when level is set at the Max. On the contrary, if your under the Min level, you risk sucking air into the radiator, as the coolant in the engine cools and contracts.

I joined in 2020, when I owned my 3500 SRW 6.7 HO 4X4, which I traded in for the 1500 in 2023.

 

[Jako]

Medical tape?

It came from an EMS kit, had an old partial roll. The same tape they stick on the gauze after having blood drawn. There is a picture of it on the dipstick in the thread I posted.
Update: I believe it is this style of medical tape

Amazon.com

 

[HSKR R/T]

For starters, to use your words, coolant can be checked hot or completely cool, just shouldn't be checked when temps are somewhere in between.

2nd, Yes, coolant has water in it. Contrary to your statement, the system is sealed and under pressure when at operating temps. No water vapors can escape under normal conditions.

Overflow bottle is vented to the atmosphere. It's designed to push coolant out. I agree that it won't push anything out when slightly overfilled. OP says he added 40 ounces. That would be a lot more than slightly overfilled.

The coolant on our 2020 Limited is still showing at the min mark when the engine is cold. I have never added coolant to this truck.

So I was wrong with the cold/hot checking. I will own that.

 

[mikeru82]

I'll answer most of your questions, 1st, I bought it used in 2023, at that time I checked the coolant level with a cold engine, and I filled it to the Max level. That was with 29K miles, the level was somewhere in the middle of the range when I bought it, BTW that is per the owners manual, checking it cold. I just drove a 600 mile round trip, and because the temps I reported earlier with fan running, I thought be a good idea to check it. Its not a sealed system, the normal operation of the coolant is, that it expands when hot and any pressure over 16 psi will dump into the reservoir. When it cools, the fluid is pulled back into the radiator as it contracts. You can lose some to evaporation but it should be minimal. You should not lose any fluid when level is set at the Max. On the contrary, if your under the Min level, you risk sucking air into the radiator, as the coolant in the engine cools and contracts.

I joined in 2020, when I owned my 3500 SRW 6.7 HO 4X4, which I traded in for the 1500 in 2023.

Appreciate the response. So it's possible this truck had an issue with losing coolant before you bought it.

Yeah, I knew I didn't word it well when I said it was a sealed system after posting that. Coolant does move back and forth between the coolant tank and radiator. I thought Rick3478's description of "not sealed, regulated" was pretty accurate. But the amount of evaporation that happens is minimal. As I mentioned, I've never needed to add coolant in our 2020 Limited since we bought it new.

Yes, the owner's manual says to check it cold. That's for liability reasons. They don't want to get sued by someone messing with the cooling system when the engine is hot and getting burned. But you can check it hot or cold. Hence the two different indicators.

Looking back now I may have been thinking of vehicles with pressurized recovery tanks. On a 2006 Pathfinder I bought used. I thought it was losing coolant after right I bought it so I would fill to the max line after it cooled off. After the next drive I'd smell coolant so I'd let it cool off and check the level. Sure enough it was back down to the lower line. Did this a couple more times before deciding to just leave it at the lower line. I never had to add coolant for the two years I had it after that. And I stopped smelling coolant after driving. Since then I never fill to the max line when the engine is cool.

I was wrong about it being "bad" to overfill on these trucks. The worst that will happen is it will push out any excess if it's full enough.