Coolant temp constantly bounces around.

[ACE2014RAM]

Hello all. I bought a used 2014 Ram with the 5.7L. Hemi. Roughly 80,000 miles on it. When I first bought the truck the temp seemed to bounce around a little bit with the factory thermostat. I thought maybe it was going bad so I replaced the thermostat with a 185 degree thermostat. Now the temperatures go anywhere from 180-210 degrees depending on load demand. So far I have put 2000 miles on it and it’s still doing the same thing. I haven’t seen it go above 210 but I feel like it might if I push it hard enough. Anyone else seen this issue before? Thanks In advance for the help.

 

[Dinky]

Hello all. I bought a used 2014 Ram with the 5.7L. Hemi. Roughly 80,000 miles on it. When I first bought the truck the temp seemed to bounce around a little bit with the factory thermostat. I thought maybe it was going bad so I replaced the thermostat with a 185 degree thermostat. Now the temperatures go anywhere from 180-210 degrees depending on load demand. So far I have put 2000 miles on it and it’s still doing the same thing. I haven’t seen it go above 210 but I feel like it might if I push it hard enough. Anyone else seen this issue before? Thanks In advance for the help.

Have you removed the active shutter?

 

[Burla]

Or radiator fan or clutch, likely one or the other. Look up fan upgrade here.

 

[Wild one]

Hello all. I bought a used 2014 Ram with the 5.7L. Hemi. Roughly 80,000 miles on it. When I first bought the truck the temp seemed to bounce around a little bit with the factory thermostat. I thought maybe it was going bad so I replaced the thermostat with a 185 degree thermostat. Now the temperatures go anywhere from 180-210 degrees depending on load demand. So far I have put 2000 miles on it and it’s still doing the same thing. I haven’t seen it go above 210 but I feel like it might if I push it hard enough. Anyone else seen this issue before? Thanks In advance for the help.

Maybe try a differant thermostat,i've had a couple brand new thermostats lately,that were duds right out of the box

 

[Burn2k12Ram]

If replacing the factory 203 with 185 thermostat doesn't one need to tune for it? Because isn't the computer trying to allow it to get warmer to match the 203?

 

[crazykid1994]

Factory 203 will run up to almost 220° due to the ags. When opened it’ll fluctuate back down to 203. The 185° may not be the best idea when not tuned just because the engine may run a bit richer to bring temps up and the ags may stay closed more to keep temps higher.

 

[Wild one]

Factory 203 will run up to almost 220° due to the ags. When opened it’ll fluctuate back down to 203. The 185° may not be the best idea when not tuned just because the engine may run a bit richer to bring temps up and the ags may stay closed more to keep temps higher.

They go into closed loop at roughly 160,so as long as it's over those temps,it shouldn't run rich. I've ran 180 t-stats in several late model Chryco's and never had any issues with them running rich,with-out tuning or playing with the fuel trims,so i doubt the thermostat is causing it to run rich,or would explain his fluctating temps.If his water pump is good,and the rad isn't plugged (which i highly doubt,as the temps wouldn't drop if the rad was the issue),it kind of makes you wonder if his replacement t-stat isn't a bit of a dud.I've ran into 2 new 180 t-stats lately that were duds right out of the box,one was even a high flow Milodon thermostat.

 

[Burn2k12Ram]

And the shutter will almost remain closed to try and

They go into closed loop at roughly 160,so as long as it's over those temps,it shouldn't run rich. I've ran 180 t-stats in several late model Chryco's and never had any issues with them running rich,with-out tuning or playing with the fuel trims,so i doubt the thermostat is causing it to run rich,or would explain his fluctating temps.If his water pump is good,and the rad isn't plugged (which i highly doubt,as the temps wouldn't drop if the rad was the issue),it kind of makes you wonder if his replacement t-stat isn't a bit of a dud.I've ran into 2 new 180 t-stats lately that were duds right out of the box,one was even a high flow Milodon thermostat.

Great points really crazy the lack of QA on parts now days even from reputable companies.

 

[turkeybird56]

Sounds like a thermostat if all other good. MY DT 19 Truck, with the E Fan, runs 199-222 F, friggin annoying. I did take it in to Dealer and they said all Sensors were OK so "They" ordered a new 850 W fan, 1 Feb 2022. Not know which slow boat from wherever it is? LOL. Not know when will arrive.

I would put in another stat first, if U R OK with the radiator functioning properly, water pump good and proper coolant mix. Just IMHO...

ADDED: OP, here's a thought. Did U burp the system after putting in new stat, ie., to get all air out of system? That could be an issue also.

 

[turkeybird56]

And the shutter will almost remain closed to try and

Great points really crazy the lack of QA on parts now days even from reputable companies.

Definitely keep receipt if buying parts these days, LOL.

 

[Burn2k12Ram]

Definitely keep receipt if buying parts these days, LOL.

I learned that with my GMC and older RAM. Lets see, bad new wheel hub, bad new EGR valve, bad new fan clutch on my older RAM lol.

 

[turkeybird56]

I learned that with my GMC. Lets see, bad new wheel hub, bad new EGR valve, bad new fan clutch on my older RAM lol.

Oh Yeah, why if I "buy" ne thing of a higher value, I always use a CC, easier ref refunds etc.,.

 

[Dusty]

Hello all. I bought a used 2014 Ram with the 5.7L. Hemi. Roughly 80,000 miles on it. When I first bought the truck the temp seemed to bounce around a little bit with the factory thermostat. I thought maybe it was going bad so I replaced the thermostat with a 185 degree thermostat. Now the temperatures go anywhere from 180-210 degrees depending on load demand. So far I have put 2000 miles on it and it’s still doing the same thing. I haven’t seen it go above 210 but I feel like it might if I push it hard enough. Anyone else seen this issue before? Thanks In advance for the help.

Under what kind of driving conditions does this occur?

Frankly, I'm really thinking it is acting normal. I still have the factory thermostat and when I tow my 7000 lb. tractor and trailer I typically see a fluctuation of sometimes 10-12 degrees, especially going up steep grades. Some of that is likely due to increase in transmission temperature. Around town it seems more steady depending on the length of the drive and ambient temps. In any event, in this respect my DT '19 acts exactly like my previous 2010 and 2014.

Coolant temp overshoot is not uncommon in just about any system when you increase the load.

Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 73766 miles

 

[turkeybird56]

Under what kind of driving conditions does this occur?

Frankly, I'm really thinking it is acting normal. I still have the factory thermostat and when I tow my 7000 lb. tractor and trailer I typically see a fluctuation of sometimes 10-12 degrees, especially going up steep grades. Some of that is likely due to increase in transmission temperature. Around town it seems more steady depending on the length of the drive and ambient temps. In any event, in this respect my DT '19 acts exactly like my previous 2010 and 2014.

Coolant temp overshoot is not uncommon in just about any system when you increase the load.

Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 73766 miles

I am not 100% sure OP actually has a problem, as my truck will run mighty warm when towing, especially down here in TX. But OP could put in a slightly lower thermostat and that may help, provided all the systems are working properly.

 

[ACE2014RAM]

Have you removed the active shutter?

Active shutter?

 

[ACE2014RAM]

Under what kind of driving conditions does this occur?

Frankly, I'm really thinking it is acting normal. I still have the factory thermostat and when I tow my 7000 lb. tractor and trailer I typically see a fluctuation of sometimes 10-12 degrees, especially going up steep grades. Some of that is likely due to increase in transmission temperature. Around town it seems more steady depending on the length of the drive and ambient temps. In any event, in this respect my DT '19 acts exactly like my previous 2010 and 2014.

Coolant temp overshoot is not uncommon in just about any system when you increase the load.

Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 73766 miles

Driving condition were 85ish degrees. Straight truck, no trailer running about 75mph up and down some pretty steep grades. With 185 degree thermostat i didnt figure it would get up to 205-210 but maybe im mistaken.

 

[ACE2014RAM]

They go into closed loop at roughly 160,so as long as it's over those temps,it shouldn't run rich. I've ran 180 t-stats in several late model Chryco's and never had any issues with them running rich,with-out tuning or playing with the fuel trims,so i doubt the thermostat is causing it to run rich,or would explain his fluctating temps.If his water pump is good,and the rad isn't plugged (which i highly doubt,as the temps wouldn't drop if the rad was the issue),it kind of makes you wonder if his replacement t-stat isn't a bit of a dud.I've ran into 2 new 180 t-stats lately that were duds right out of the box,one was even a high flow Milodon thermostat.

so i have no reason to worry about my engine running to rich? i wasnt aware of this if thats true. Maybe just need to tune my fan to a lower temperature? And what is AGS? maybe a dumb question

 

[Wild one]

so i have no reason to worry about my engine running to rich? i wasnt aware of this if thats true. Maybe just need to tune my fan to a lower temperature? And what is AGS? maybe a dumb question

Active grill shutters,if you have the 8 speed odds are you have the shutters.

 

[Burn2k12Ram]

so i have no reason to worry about my engine running to rich? i wasnt aware of this if thats true. Maybe just need to tune my fan to a lower temperature? And what is AGS? maybe a dumb question

on first startup think of it like closed window blinds allows the truck to get up to temperature then opens when truck up to temp.

 

[Mister Luck]

You know auto transmissions have their own coolant thermostat ? Meaning it will affect your coolant temps also.