How to lower coolant temp?

[RamDiver]

Yes. I'd like to know if there is a way to lower my fan kick on temp in my 2024. I'm considering getting AlfaOBD, but not sure if that can do it.

AlfaOBD will not adjust the fan startup threshold.

AFAIK, you need a tuner for that adjustment.

.

 

[NCRaineman]

Assuming you have at least some antifreeze mixed in with the water, I can assure you that your coolant will NOT boil at 220°F; although I wouldn't want my engine (any engine, really) running at that temp either. With a 180°F thermostat, lowering the electric fan(s) kick-on temp, and removing the shutters, I'm guessing that your temps will stay between 180°F to 190°F at the most. As long as you leave the AGS solenoid connected, you should be fine. The ECU can't detect whether the shutters actually open/close (or if they are even there) as far as I know.. unless there is something like a limit switch that gets triggered and sends a signal back to tell the computer it has reached fully open / fully closed. I'm not actually familiar with the specifics of that system.

Also worth mentioning though.. there are a lot of other systems that require the vehicle to reach 'operating temperature' before they kick in. Like the EGR circuit, for example. With a 180°F thermostat, the truck will never reach the factory set 'operating temp' which I'm guessing is probably 195°F. So you'd need to change that in VCM Editor also (if that's possible).

Also, this is a fantastic product (don't ask me how it works.. it's some form of magic.. but just adding this alone WILL drop your ECT by at least 5-10 degrees):

View attachment 559989

I tried Water Wetter in our Ram after having success with it in a couple of Chevys over the years. Have not been impressed with its performance in the truck. I'm not convinced it has made any difference at all.

These engines run hot from the factory. All new vehicles do. It's an emissions thing. The fastest and easiest way to see results is to get a tuner and command the fans on at a lower temperature. Of course since the ECU has to be replaced with an unlocked one before you can tune that's going to set you back several hundred dollars. Also, as mentioned, other systems are dependent upon the engine getting "up to temp" and if you mess with things too much that will never happen.

Best advice, unless you are constantly seeing temps of 225+, is just to leave the cooling system alone.

 

[Wild one]

Yes. I'd like to know if there is a way to lower my fan kick on temp in my 2024. I'm considering getting AlfaOBD, but not sure if that can do it.

Turn the A/C on,it should kick the fan into gear,on the 4th Gens turning the heater controls to defrost would usually turn on the fans low speed setting,not sure if that works on the 5th Gens,but you can try and see if it does

 

[stevieb92]

Turn the A/C on,it should kick the fan into gear,on the 4th Gens turning the heater controls to defrost would usually turn on the fans low speed setting,not sure if that works on the 5th Gens,but you can try and see if it does

I have done that and it works. However, the engine shouldn't get that hot when the ambient temp outside is 65F. I don't want to always run around with the A/C on when it's not needed.

 

[Wild one]

I have done that and it works. However, the engine shouldn't get that hot when the ambient temp outside is 65F. I don't want to always run around with the A/C on when it's not needed.

Then you're buying a tuner and unlocked PCM if you want to lower the fans on/off parameters.Did you try turning the heater controls to defrost with-out the A/C on?

 

[stevieb92]

Then you're buying a tuner and unlocked PCM if you want to lower the fans on/off parameters.Did you try turning the heater controls to defrost with-out the A/C on?

Bummer. I was hoping there was another option than a tuner and unlocked pcm. I have not tried that. Doesn't defrost still turn on the A/C compressor in the background?

 

[Wild one]

Bummer. I was hoping there was another option than a tuner and unlocked pcm. I have not tried that. Doesn't defrost still turn on the A/C compressor in the background?

See if defrost cycles the fan on,and report back,as nobodies ever said if the 5th Gens work like the 4th Gens

 

[Mojo88]

UPDATE ON THE 180* MISHIMOTO T-STAT INSTALL:
This is with outside temps ~35*
Cruising temp, now 185*-190* (was ~205*).
Around town, slow speeds, now ~200* (was ~220*)
Have not adjusted fan limits, nor have I removed any AGS slats.
I am gonna leave it alone at this point. Hopefully no CEL issues appear. But seeing as it still does occasionally get up to ~200* I would 'assume' the system is happy. We shall see.

SIDENOTE: engine feels a tiny bit peppier, perhaps it's just my imagination.

 

[2023RAM1500ds]

ECT (engine coolant temp) hovers slightly above 200* during normal driving. But starts going up as soon as I slow down. Today I was driving slowly around the block looking for a parking space, outside temp was chilly 35*, ECT was boiling 220*.

I bought this truck a few months ago. I'm worried that it's gonna overheat in Summer with A/C on??? Should I take steps to lower ECT?

I have HPTuners new unlocked PCM coming, and I was hoping to modify the AGS (active grill shutters) open/close temp limits, but apparently that's not possible, even with HPTuners and an unlocked PCM, jeesh.....

when did you last change your coolant?

 

[Mojo88]

I've only had the truck ~4 months, 58k miles now. Coolant looked pretty clean, I replaced 2 gallons during the t-stat swap.

 

[2023RAM1500ds]

I've only had the truck ~4 months, 58k miles now. Coolant looked pretty clean, I replaced 2 gallons during the t-stat swap.

The electric fan might not be working properly, think of it like those computer fans.. electric, as they get dirty they end up slowing down, thus raising internal temps...
On your truck they've been running everyday, and are exposed to outside dirt etc.. might need a new fan...

 

[greygray]

think of it like those computer fans.. electric, as they get dirty they end up slowing down

That's not a thing.

 

[sooper cooper]

Yeah, thanks, a new stat is definitely on the menu, as are fan limit adjustments. I'm really perplexed about no ability to adjust limits on the AGS. I would have bet a lot of money that HPTuners would allow me to tweak the AGS, but noooooo. I am gonna send them an email and see if they can update their software to allow this function. It makes no sense that you can adjust/tweak EVERYTHING else, but not the AGS.

If I install a 180* stat, change fan limits and remove AGS shutters (but leave the operating solenoid wired and in place)... then I would guess ECT temps would average ~185*-190*. Does anyone know, would this trigger a CEL (check engine light)? Because at those temps, the AGS solenoid would be telling the shutters to remain closed all the time. And if the shutters are closed ALL THE TIME (for any reason), then I would think that would trigger a CEL, maybe for something like "ECT temps too cool". Or perhaps a CEL is triggered if engine temps don't reach at least 195*???

 

[sooper cooper]

I left the top and bottom slats on each side (no CEL) installed 180* t-stat, maintains at 185*

 

[Mojo88]

I left the top and bottom slats on each side (no CEL) installed 180* t-stat, maintains at 185*

I may take some slats out, if necessary. 180* stat seems to be working good.

I was looking for an excuse to utilize my new HPTuners setup, so I went in and adjusted the fan settings, to come on a little earlier, and I disabled MDS. So far those are my only tweaks using HPTuners.

 

[Wild one]

I may take some slats out, if necessary. 180* stat seems to be working good.

I was looking for an excuse to utilize my new HPTuners setup, so I went in and adjusted the fan settings, to come on a little earlier, and I disabled MDS. So far those are my only tweaks using HPTuners.

If you haven't watched this video,spend the 16 minutes it takes to watch it right to the end.

Is MDS Damaging Your HEMI? The Answer May Surprise You!

I feel like MDS has been unfairly made the culprit for the lifter failures we see on Gen 3 Hemi engines. In this video I explain exactly how the system works...

www.youtube.com

 

[Mojo88]

If you haven't watched this video,spend the 16 minutes it takes to watch it right to the end.

Is MDS Damaging Your HEMI? The Answer May Surprise You!

I feel like MDS has been unfairly made the culprit for the lifter failures we see on Gen 3 Hemi engines. In this video I explain exactly how the system works...

www.youtube.com

Yeah, thanks, I did watch that vid before. Thing is, I notice a Helluva difference with the MDS disabled. Maybe my MDS was coming on too much, I don't know. But with it disabled, I honestly feel like I've installed a custom tune or something. It's noticeably smoother and more responsive.

My plan is to basically change oil/filter every ~3k miles, plus add extra 1/2 quart of oil.............. so hopefully that prevents disaster.

 

[Hemi395]

UPDATE ON THE 180* MISHIMOTO T-STAT INSTALL:
This is with outside temps ~35*
Cruising temp, now 185*-190* (was ~205*).
Around town, slow speeds, now ~200* (was ~220*)
Have not adjusted fan limits, nor have I removed any AGS slats.
I am gonna leave it alone at this point. Hopefully no CEL issues appear. But seeing as it still does occasionally get up to ~200* I would 'assume' the system is happy. We shall see.

SIDENOTE: engine feels a tiny bit peppier, perhaps it's just my imagination.

Now that its been a few months, how is the Mishimoto tstat doing?

 

[Mojo88]

Now that its been a few months, how is the Mishimoto tstat doing?

Oh man, it's been dead-nuts perfect. Cruise temp is ~185, and when I slow down for stop & go traffic, occasional blip to 197*, then AGS and fan activate, and temp drops back to ~185* within 30 seconds. It's just wonderful. No CEL's or anything either.

This past winter, prior to all these mods, my truck was hitting ~235* in stop & go traffic, even with exterior temps at ~30*!!! It was ridiculous. One time it went up to 238*, and when that happened, I freaked out a little bit, then I couldn't take my eyes off the temp reading, I was glancing at it every few seconds, lol. I became obsessively annoyed with it...... and I knew it was time for a change.

So far, with the help of HPTuners, I've done these things;
1) 180* stat and modded PWM fan settings,
2) Turned off MDS in the tune,
3) Advanced part-throttle timing ~4*,
4) Adjusted part-throttle shift points higher.

All were small, careful, modest changes...... focused solely on part-throttle rpm range. I did not change anything for WOT. But for everyday driving, this truck now has an astonishingly different feel to it from the day I bought it.

 

[Hemi395]

Oh man, it's been dead-nuts perfect. Cruise temp is ~185, and when I slow down for stop & go traffic, occasional blip to 197*, then AGS and fan activate, and temp drops back to ~185* within 30 seconds. It's just wonderful. No CEL's or anything either.

This past winter, prior to all these mods, my truck was hitting ~235* in stop & go traffic, even with exterior temps at ~30*!!! It was ridiculous. One time it went up to 238*, and when that happened, I freaked out a little bit, then I couldn't take my eyes off the temp reading, I was glancing at it every few seconds, lol. I became obsessively annoyed with it...... and I knew it was time for a change.

So far, with the help of HPTuners, I've done these things;
1) 180* stat and modded PWM fan settings,
2) Turned off MDS in the tune,
3) Advanced part-throttle timing ~4*,
4) Adjusted part-throttle shift points higher.

All were small, careful, modest changes...... focused solely on part-throttle rpm range. I did not change anything for WOT. But for everyday driving, this truck now has an astonishingly different feel to it from the day I bought it.

That's great news!! I have a Mishimoto 180 ready to go in but I had read some posts on the FB groups of the Mishimotos failing too. I have a Mopar one in my truck now but the coolant and oil temps get hotter than I'd like so I really would like to run a 180.

Glad yours is working out for you and I think I'm gonna install my Mishimoto based on your experience.