3.6L Radiator Fan Problem?

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SitKneelBend

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The other day when parking in my garage I noticed my coolant temps getting up to 230 before going back down to about 219. It wasn't a very hot day, maybe mid 70s and about a mile of mild driving before reaching my house in the neighborhood.

I plan on changing the coolant soon but before I do I wanted to know if this electric fan behavior seems normal to anyone and/or if someone knows exactly which temperature my PWM fan should be ramping up at. At present, the fan only comes on under two scenarios:

1. When the coolant temp reaches 230 (then drops to about 219 and turns off)

2. When I turn on the AC (turns on a few seconds after engaging and remains on continuously, temperatures hover around 213 with AC on)

It seems to only be running at only one speed too but I remember it being louder in the past and ramping up when idling. Occasionally when it's below 230 I will see it wobble left to right like it was about to turn on but then stops. Additionally, I will occasionally hear a high pitched whine when I shut off the vehicle for a short time. I've tried using AlfaOBD to see if I can engage the PWM test but all I here is a click sound when I start the test and another (slightly different whine) sound then another click when the test ends with the fan never having engaged (not even the left right wobble). What I think is happening is that the fan is only moving when commanded by the PCM to be on high-speed but it is only spinning at low-speed.

Any thoughts? Anyone deal with something similar? Do I need a new fan or could this be something else?

2014 Ram 1500 Express 3.6L 4x4 845RE
 

Atcer2018

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The other day when parking in my garage I noticed my coolant temps getting up to 230 before going back down to about 219. It wasn't a very hot day, maybe mid 70s and about a mile of mild driving before reaching my house in the neighborhood.

I plan on changing the coolant soon but before I do I wanted to know if this electric fan behavior seems normal to anyone and/or if someone knows exactly which temperature my PWM fan should be ramping up at. At present, the fan only comes on under two scenarios:

1. When the coolant temp reaches 230 (then drops to about 219 and turns off)

2. When I turn on the AC (turns on a few seconds after engaging and remains on continuously, temperatures hover around 213 with AC on)

It seems to only be running at only one speed too but I remember it being louder in the past and ramping up when idling. Occasionally when it's below 230 I will see it wobble left to right like it was about to turn on but then stops. Additionally, I will occasionally hear a high pitched whine when I shut off the vehicle for a short time. I've tried using AlfaOBD to see if I can engage the PWM test but all I here is a click sound when I start the test and another (slightly different whine) sound then another click when the test ends with the fan never having engaged (not even the left right wobble). What I think is happening is that the fan is only moving when commanded by the PCM to be on high-speed but it is only spinning at low-speed.

Any thoughts? Anyone deal with something similar? Do I need a new fan or could this be something else?

2014 Ram 1500 Express 3.6L 4x4 845RE

I recently replaced the oil filter housing/cooler and changed the coolant while I had it apart. I found the same temps as you were the norm on my 3.6. Highway the truck would cruise 60-65 with a near constant 215 temp on the OEM 204 degree thermostat. Coming off the highway the temps would climb to 220 or higher and would continue to climb to 230 with any additional in town driving. At 230 the fan would kick on and remain on till temps came down to 215-ish. Unfortunately the oil temps remain high and personally 230 coolant and oil temps worry me. I know that Jeeps use the 3.6 more than Rams so I searched the Jeep forums and found this is a pretty standard temp range on the 3.6. Unfortunately I was fat, dumb and happy before the oil cooler started leaking and never paid attention to what the old readings were prior to the repair. From what I gathered on the Jeep forums the electric fan comes on low at 212F and high at 230F. I’m not sure if or how this works as it would seem to me that the low fan would operate at the highway speeds of 215 but checking it’s operation at 215 or greater it’s not operating on my truck. Since I live in the southeast and we don’t really have a winter season I elected to delete all but the top and bottom row of the AGS. This in itself has lowered my engine coolant and oil temps drastically. I never see temps over 220 now even in city driving and it was 82F outside temps a few days ago. On the highway it’s steady at 200F @ 65mph and only rises to 210F coming off the highway. To the best of my knowledge the AGS delete does not have any adverse effect as some 3.6 trucks come from the factory without AGS although I do not know if these vehicles have different e-fan programming.
 
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SitKneelBend

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I recently replaced the oil filter housing/cooler and changed the coolant while I had it apart. I found the same temps as you were the norm on my 3.6. Highway the truck would cruise 60-65 with a near constant 215 temp on the OEM 204 degree thermostat. Coming off the highway the temps would climb to 220 or higher and would continue to climb to 230 with any additional in town driving. At 230 the fan would kick on and remain on till temps came down to 215-ish. Unfortunately the oil temps remain high and personally 230 coolant and oil temps worry me. I know that Jeeps use the 3.6 more than Rams so I searched the Jeep forums and found this is a pretty standard temp range on the 3.6. Unfortunately I was fat, dumb and happy before the oil cooler started leaking and never paid attention to what the old readings were prior to the repair. From what I gathered on the Jeep forums the electric fan comes on low at 212F and high at 230F. I’m not sure if or how this works as it would seem to me that the low fan would operate at the highway speeds of 215 but checking it’s operation at 215 or greater it’s not operating on my truck. Since I live in the southeast and we don’t really have a winter season I elected to delete all but the top and bottom row of the AGS. This in itself has lowered my engine coolant and oil temps drastically. I never see temps over 220 now even in city driving and it was 82F outside temps a few days ago. On the highway it’s steady at 200F @ 65mph and only rises to 210F coming off the highway. To the best of my knowledge the AGS delete does not have any adverse effect as some 3.6 trucks come from the factory without AGS although I do not know if these vehicles have different e-fan programming.
Thanks! So if I'm reading this right, I should see two speeds, one coming on at 212F and the other at 230? Before I would see the temps get to about 226 but would rarely ever go higher than that (only while hauling or traveling in the mountains).
 

Atcer2018

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Thanks! So if I'm reading this right, I should see two speeds, one coming on at 212F and the other at 230? Before I would see the temps get to about 226 but would rarely ever go higher than that (only while hauling or traveling in the mountains).

That’s the information I gathered from more than a few Jeep posts. Supposedly Jeeps have a two speed e-fan but I’m not sure the Ram 3.6 has the same setup. I can confirm my e-fan comes on at 230-ish but I have yet to confirm it operates at the 212F temp range. I don’t have a GoPro so I’ve tried pulling over when the temp on the evic shows above 212, open the hood and no e-fan operation. Maybe I’m not understanding the Ram setup or my fan isn’t operating correctly. I can confirm the temps you are seeing on your vehicle were the same as mine before the AGS delete. I’m inclined to trust my temp readings as I used new OEM oil and coolant sensors when I did the filter housing replacement. I did however use the Dorman all aluminum housing and I’ve come across a few comments that the all aluminum housing doesn’t dissipate heat as well as the OEM plastic housing. I also vacuum filled my cooling system after flushing with 10 gallons of distilled water so I doubt it’s a coolant condition or fluid level issue. My personal concern had more to do with the high oil temps as they are much slower to come down in temp than the coolant temps. For me the AGS delete was an inexpensive solution but yours may be a faulty e-fan. Please let us know what you find out from your testing.
 
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SitKneelBend

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That’s the information I gathered from more than a few Jeep posts. Supposedly Jeeps have a two speed e-fan but I’m not sure the Ram 3.6 has the same setup. I can confirm my e-fan comes on at 230-ish but I have yet to confirm it operates at the 212F temp range. I don’t have a GoPro so I’ve tried pulling over when the temp on the evic shows above 212, open the hood and no e-fan operation. Maybe I’m not understanding the Ram setup or my fan isn’t operating correctly. I can confirm the temps you are seeing on your vehicle were the same as mine before the AGS delete. I’m inclined to trust my temp readings as I used new OEM oil and coolant sensors when I did the filter housing replacement. I did however use the Dorman all aluminum housing and I’ve come across a few comments that the all aluminum housing doesn’t dissipate heat as well as the OEM plastic housing. I also vacuum filled my cooling system after flushing with 10 gallons of distilled water so I doubt it’s a coolant condition or fluid level issue. My personal concern had more to do with the high oil temps as they are much slower to come down in temp than the coolant temps. For me the AGS delete was an inexpensive solution but yours may be a faulty e-fan. Please let us know what you find out from your testing.
I think it's most likely the fan, here is a great write-up (again Jeep but same engine and should apply to the Ram too from everything I can see)...


Edit: I'm going to pick your brain on the coolant replacement if you don't mind. I find lots of info for the 5.7L but not much for the 3.6L and that's next on my list after the transmission fluid/pan swap.
 
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SitKneelBend

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@Atcer2018 , quick question, do you have a 60A amp fuse in F03 (marked 3 on this diagram)? On mine I just have the 80A fuse in F01.

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1713531485429.png
 

Atcer2018

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SitKneelBend

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No fuse or relay. Attached are pics of mine. In my fuse box it states F03 RAD FAN HI/LO and F3 is empty.
Perfect, looks just like mine. I may have made some progress and found the culprit. After looking at the Jeep write-up from realjenius, I decided to get out the multimeter and test the connections. It appears the ground goes to the factory ground location next to the TIPM here:

1713542445603.png

To test, I unplugged the efan and checked the voltage between the red 12v and the black ground at the plug, I was reading 12.09v. I then checked from the Red 12v at the plug and the ground location with the ground wires unbolted, It read 12.26v. So I got out some sandpaper, a metal brush, and some Krown lubricant to clean everything on the grounding location and buttoned everything back up. I am now reading 12.26v at the efan plug so the ground was successfully improved.

I let the truck idle in my driveway and when the truck reached 195 the fan kicks on low now. For good measure I took the plug back off and cleaned with QD electronics cleaner. I'm letting that dry then I'm taking it on a test drive. I'll let you know what I find.

For anyone else who may come across this, I called my dealership and gave them my VIN for the part number for the Radiator electric fan assembly, $508 P/N 52014772AF but looks like it can be had for $300-$350 on Amazon.
 

Atcer2018

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Excellent! Checking the ground and voltage is now on my to do list as I don’t see any low speed fan operation. Thank you for the excellent write up.
 

Atcer2018

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Edit: I'm going to pick your brain on the coolant replacement if you don't mind. I find lots of info for the 5.7L but not much for the 3.6L and that's next on my list after the transmission fluid/pan swap.


Pick away but I doubt you’ll be satisfied with my old school method. I simply put a section of poly hose on the lower radiator petcock, broke the seal open with a pair of slip joint pliers and let the radiator and upper hose drain. The first time you open the petcock it’s a PITA. It’s stuck in there pretty good and it’s a tight fit around the supports and lower coolant hose. I pulled the whole plug shaft out by continuing to turn it counterclockwise until it comes out. Check the o-ring seal and give it a shot of your favorite lube. You have to push and turn clockwise to pop it back in. Subsequent openings are much easier. I emptied the overflow reservoir using a giant syringe suction thing. Filled the reservoir and radiator with distilled water and cracked open the bleed valve on the thermostat. You can hear the air escape. The bleed valve is a tight fit against the crossover pipe and a big wire harness running over top of it. I put the front wheels up on ramps, turned the heat on high and used a burp funnel to fill full by running the engine at idle until the thermostat opened and I watched the bubbles come out. Took about a gallon and a half. Took it on a 15 minute drive and parked it for two hours. Repeated the process again but added a bottle of RMI25 because I was concerned about oil contamination from the leaky cooler. Drove it again for 10 minutes and repeated the same process till I had 15 gallons of distilled water through the system. After the 15 gallons was run through I added the concentrate 10 year 150k mile purple antifreeze and took it on a 30 minute drive. Parked it and waited about 3 hours, drained it and added a second gallon of concentrate using a vacuum suction fill tool. It took three days doing it my way because I was too lazy to find the block plugs and drain the block. Is my concentration correct? I doubt it but I live down south and we have very mild winters. The system holds 14 quarts. I doubt you’ll need a cleaning additive like RMI25. A section of poly hose I believe 5/8, drain pan and any type of drip pan or plastic tarp under the area below the engine where the thermostat bleeder drips, antifreeze, suction pump and a few wrenches are all you’ll need
 
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SitKneelBend

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Pick away but I doubt you’ll be satisfied with my old school method. I simply put a section of poly hose on the lower radiator petcock, broke the seal open with a pair of slip joint pliers and let the radiator and upper hose drain. The first time you open the petcock it’s a PITA. It’s stuck in there pretty good and it’s a tight fit around the supports and lower coolant hose. I pulled the whole plug shaft out by continuing to turn it counterclockwise until it comes out. Check the o-ring seal and give it a shot of your favorite lube. You have to push and turn clockwise to pop it back in. Subsequent openings are much easier. I emptied the overflow reservoir using a giant syringe suction thing. Filled the reservoir and radiator with distilled water and cracked open the bleed valve on the thermostat. You can hear the air escape. The bleed valve is a tight fit against the crossover pipe and a big wire harness running over top of it. I put the front wheels up on ramps, turned the heat on high and used a burp funnel to fill full by running the engine at idle until the thermostat opened and I watched the bubbles come out. Took about a gallon and a half. Took it on a 15 minute drive and parked it for two hours. Repeated the process again but added a bottle of RMI25 because I was concerned about oil contamination from the leaky cooler. Drove it again for 10 minutes and repeated the same process till I had 15 gallons of distilled water through the system. After the 15 gallons was run through I added the concentrate 10 year 150k mile purple antifreeze and took it on a 30 minute drive. Parked it and waited about 3 hours, drained it and added a second gallon of concentrate using a vacuum suction fill tool. It took three days doing it my way because I was too lazy to find the block plugs and drain the block. Is my concentration correct? I doubt it but I live down south and we have very mild winters. The system holds 14 quarts. I doubt you’ll need a cleaning additive like RMI25. A section of poly hose I believe 5/8, drain pan and any type of drip pan or plastic tarp under the area below the engine where the thermostat bleeder drips, antifreeze, suction pump and a few wrenches are all you’ll need
What vacuum pump do you use? I think your way is about the same way I'll be doing it too...
 
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SitKneelBend

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Excellent! Checking the ground and voltage is now on my to do list as I don’t see any low speed fan operation. Thank you for the excellent write up.
Ok, after a test drive I'm still seeing the same behavior but only at idle. I'm not sure why the fan turns on at 195, maybe because that's when the thermostat opens and it wants to deal with a rush of engine coolant coming through the radiator? It will come on at 195, then turn off about 190 BUT I'm still not seeing it come on any other time then at about 228 and then shuts off again around 219. It seems to always be running at the same speed regardless of temperature too. If I turn on the A/C it will go all the way down to about 199 with the fan constantly running. I was able to get it to throw a code only if I started the truck with the fan unplugged (P0480). If you unplug the fan, be sure to seat it firmly and wait to hear a click before assuming it's on there.

I think my next step will be to order this fan from Amazon because it has free returns and see if it behaves differently...


I don't know why, but I feel like I remember the fan being much louder and sometimes running for a while after the truck was shut off...
 

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My truck runs at 194-197 on the road with all but the top, middle, and bottom shutter in place. My temp when in traffic or going up mountains gets up to 228-230 before dropping down.

I hate it. This can't be good for an all aluminum engine. I can find no way to change the settings since these are PWM fans, If it was a regular 12 volt fan I would run a switched 12 volt wire to the hot side and turn it on when the temps started to climb.

I keep saying I'm going to put a pusher fan on the front of the radiator, and just turn it off and on as needed, but haven't done it yet.

I checked my relays, and the plug at the A/C line and the fan. That seemed to make the fan turn on more consistent, as I had never heard it when stopping the engine before, but now do.

Engine still gets to 228 at times though.

If there was any way to reprogram the fan temp settings, I would gladly pay up to $400.00-$500.00 to do it other than put in an extra pusher fan, if it could be done quickly and easily, without having to send the PCM off somewhere.
 

turkeybird56

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My truck runs at 194-197 on the road with all but the top, middle, and bottom shutter in place. My temp when in traffic or going up mountains gets up to 228-230 before dropping down.

I hate it. This can't be good for an all aluminum engine. I can find no way to change the settings since these are PWM fans, If it was a regular 12 volt fan I would run a switched 12 volt wire to the hot side and turn it on when the temps started to climb.

I keep saying I'm going to put a pusher fan on the front of the radiator, and just turn it off and on as needed, but haven't done it yet.

I checked my relays, and the plug at the A/C line and the fan. That seemed to make the fan turn on more consistent, as I had never heard it when stopping the engine before, but now do.

Engine still gets to 228 at times though.

If there was any way to reprogram the fan temp settings, I would gladly pay up to $400.00-$500.00 to do it other than put in an extra pusher fan, if it could be done quickly and easily, without having to send the PCM off somewhere.
I am not in your boat, BUT: 5.7L, Fan was diagnosed bad 2 years ago in 2022: IT took me 2 years and 21 days to finally get the fan replaced under my MAX Care warranty. Now the 5.7's are tuned ref fan a lil different, truck has stock 203F stat, but my truck will get up to 222F when sitting before the 850 E Fan fully spools. SO MY workaround in summer here is: When I get to my truck parking spot in front of house, put in park. Open up Climate Controls and Hit MAX air. My fan will spool up full speed and when I see temps on display down to 199F, I reach over, hit my auto button and turn off truck. The fan will also spool and run full when operating if I stay on Max cool. Other then that, got the constant temps up and down and drives me "turkey".

Just relating my experiences with MY 19 RAM as a comparison. Yardbird: I have not removed any of the shutters, but my truck is a driveway princess and only tow when I gotta take hossie to vet, or when getting hay or a super big object I cannot put in bed of truck because I have a full tonneau cover, so I use my 14' stock trailer to retrieve oversize items.
 
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SitKneelBend

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My truck runs at 194-197 on the road with all but the top, middle, and bottom shutter in place. My temp when in traffic or going up mountains gets up to 228-230 before dropping down.

I hate it. This can't be good for an all aluminum engine. I can find no way to change the settings since these are PWM fans, If it was a regular 12 volt fan I would run a switched 12 volt wire to the hot side and turn it on when the temps started to climb.

I keep saying I'm going to put a pusher fan on the front of the radiator, and just turn it off and on as needed, but haven't done it yet.

I checked my relays, and the plug at the A/C line and the fan. That seemed to make the fan turn on more consistent, as I had never heard it when stopping the engine before, but now do.

Engine still gets to 228 at times though.

If there was any way to reprogram the fan temp settings, I would gladly pay up to $400.00-$500.00 to do it other than put in an extra pusher fan, if it could be done quickly and easily, without having to send the PCM off somewhere.
Maybe talk to these guys? The programming across brands seems to be pretty similar...

 
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SitKneelBend

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For anyone following this, I haven't given up BUT I'm first going to be replacing the coolant (almost 10 years and 80,000 miles on it but looks great) and servicing the transmission and adding a PPE pan. These things need to be done anyway and I'm thinking it will give me a good point of reference (and others) for improvements in cooling before I do anything further with the fan...

On that note, I would be interested in hearing any other anecdotes from 3.6L Ram owners on what temps their fans kick on at and when they turn off. It would help us all know what is supposed to be happening since we have no published information (yet) to reference...
 

Rado

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For anyone following this, I haven't given up BUT I'm first going to be replacing the coolant (almost 10 years and 80,000 miles on it but looks great) and servicing the transmission and adding a PPE pan. These things need to be done anyway and I'm thinking it will give me a good point of reference (and others) for improvements in cooling before I do anything further with the fan...

On that note, I would be interested in hearing any other anecdotes from 3.6L Ram owners on what temps their fans kick on at and when they turn off. It would help us all know what is supposed to be happening since we have no published information (yet) to reference...
Any UPDATES ??? Thanks
 
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