AC shuts off when idling in traffic

[Dutra]

I have not done a coolant flush I will start with that. Nothing is blocking the radiator. This issue started well before the 45K mile on this pic. This was idling in traffic as well.

I can hear the AC on max work just fine while driving at any speeds and when first starting the vehicle. When in stop traffic is the issue.

 

[emjohn4]

I'll bet you that the active aero grill shutters are stuck closed.

If you were to physcially remove them, I'd bet your temps drop dramatically.

 

[indept]

View attachment 537610

I have not done a coolant flush I will start with that. Nothing is blocking the radiator. This issue started well before the 45K mile on this pic. This was idling in traffic as well.

I can hear the AC on max work just fine while driving at any speeds and when first starting the vehicle. When in stop traffic is the issue.

You say you got the efan to come on manually, how? When the engine temps start to rise and the AC shuts down, is the efan on? Is it blowing fast enough? The fan is controlled by the PCM. It pulse width modulated. If it's on when the AC stops is it blowing full speed? Check the fans connector pins for signs of getting hot. A bad connection on that could cause this too.

 

[Dean2]

You guys have done a great job of laying stuff out for the OP. Basically, if the fan is working right, thermostat is opening properly, coolant is full, Rad cap pressure tests fine and the Rad and coolers are not gunked up then the truck will not over heat. (The default fail position for the auto shutter system is open, so even if they failed that should not be the problem but easy enough to check as they go through a test cycle every time you start the truck.)

The Op insists the fan is fine, thermostat is fine, coolant is great and the Rad and coolers are clear. I cannot wait to hear what is causing this truck to over heat because it must be possessed if it is overheating and all those items are fine.

 

[RamDiver]

View attachment 537610

I have not done a coolant flush I will start with that. Nothing is blocking the radiator. This issue started well before the 45K mile on this pic. This was idling in traffic as well.

I can hear the AC on max work just fine while driving at any speeds and when first starting the vehicle. When in stop traffic is the issue.

I was asking about the last coolant flush for information, not suggesting it as the next course of action.

I also posted information on bleeding the coolant system because trapped air could create this condition.

As Dean mentioned, with all the parameters confirmed as operational, something doesn't add up as per usual.

Have you been able to identify when (temperature wise) the thermostat is opening to give us an idea of the temperature value and whether or not it is functional?

I'm also curious about what you can tell us about the following from your signature line. Was this failure confirmed or suspected and can you provide any more details?

"35,000 miles Fan motor cuts out leaving AC useless in traffic"

.

 

[JimmyO]

My 17 Ram had the same issue. No bad relay or fuses, but warmer air at idle.
After my water pump seal started leaking, I changed the water pump, thermostat, fan and fan clutch, and the belt… Ac has been fine ever since.
I’m convinced, changing the fan clutch was my solution for the Ac issue.

 

[Dutra]

I was asking about the last coolant flush for information, not suggesting it as the next course of action. I have not flushed the coolant

I also posted information on bleeding the coolant system because trapped air could create this condition.

As Dean mentioned, with all the parameters confirmed as operational, something doesn't add up as per usual. Yes, something is not working correctly

Have you been able to identify when (temperature wise) the thermostat is opening to give us an idea of the temperature value and whether or not it is functional? No

I'm also curious about what you can tell us about the following from your signature line. Was this failure confirmed or suspected and can you provide any more details? Yes, I cannot hear the fan kicking on after driving awhile and going into an idle. Takes around 30 mins at outside temps over 100 degrees and the AC stops blowing cold air. Fan turns on right at start. Cannot hear while driving the truck is loud.

"35,000 miles Fan motor cuts out leaving AC useless in traffic" FACT!

.

 

[Dutra]

My 17 Ram had the same issue. No bad relay or fuses, but warmer air at idle.
After my water pump seal started leaking, I changed the water pump, thermostat, fan and fan clutch, and the belt… Ac has been fine ever since.
I’m convinced, changing the fan clutch was my solution for the Ac issue.

There are no leaks under my truck. I also checked for small leaks and found none. Tuesday I will call the stealership and see what they can do. I have max care until 2025 they should cover the fix. Fingers crossed

 

[RamDiver]

There are many threads on Ram Forum discussing mechanical fan clutch faults. Most of the failures seem to leave the fan stuck in the engaged mode but others like yours, are not engaging.

Have a look at these videos for a good explanation of how this mechanical fan clutch assembly operates. I'm not certain how to adequately troubleshoot this fault and would have to defer to the more experienced members of this forum.

How Does a Viscous Fan Clutch Work?

Learn what makes a viscous fan clutch operate. Detailed animations show internal components.https://kit-masters.com

www.youtube.com

Viscous Fan Drives

Viscous Fan Drives offer the latest in engineering innovations, including fully modulating, cost-effective fan drives that control fan speed in direct propor...

www.youtube.com

.

 

[Dutra]

stealership got $200 from me. Ran the computer and No codes found. Going to replace the fan clutch and see what happens in another week.

 

[Choupique]

Put it in neutral and rev it up. All of the 6.4 trucks my company uses have this issue in the dog days of summer. The only thing we've found that works is more RPMs.

 

[Dutra]

For a 6 year old truck with 52,000 miles or so, should not have any issues

 

[Dutra]

I'll bet you that the active aero grill shutters are stuck closed.

If you were to physcially remove them, I'd bet your temps drop dramatically.

How much you got? My truck doesn't have the grill shutters. Fan clutch is stuck

Trying to upload a video but cannot. My 24 year old Tacoma with 292,000 miles the fan is very hard to turn by hand. On my dodge the fan moves with little effort. My neighbor has a 2020 ram 3500 and the fan moves with tension similar to the Tacoma

 

[04fxdwgi]

How much you got? My truck doesn't have the grill shutters. Fan clutch is stuck

Trying to upload a video but cannot. My 24 year old Tacoma with 292,000 miles the fan is very hard to turn by hand. On my dodge the fan moves with little effort. My neighbor has a 2020 ram 3500 and the fan moves with tension similar to the Tacoma

Sounds like the clutch fan fluid is no more.... Should present resistance when turning by hand.

 

[Dutra]

Sounds like the clutch fan fluid is no more.... Should present resistance when turning by hand.

100% agree. Just curious how that can happen on a low mileage vehicle.

 

[Rado]

100% agree. Just curious how that can happen on a low mileage vehicle.

Parts are not made as good as they used to be !So they wear out or break faster IMO

 

[OCDTech]

My brothers 15 Hemi is cold while driving, barely cool at idle, (the a/c that is). E fan roaring out there, so its only supplemental im guessing, I read somewhere long ago that manual clutch fans fail usually by so many rpms a year or something like that, in other words it doesnt have to fail all at once, can just start slipping more and more.

 

[04fxdwgi]

My brothers 15 Hemi is cold while driving, barely cool at idle, (the a/c that is). E fan roaring out there, so its only supplemental im guessing, I read somewhere long ago that manual clutch fans fail usually by so many rpms a year or something like that, in other words it doesnt have to fail all at once, can just start slipping more and more.

The truck also has an electric fan that runs full time while AC is on, but are known to crap out or have a failed relay driving them.. Does that fan come on with the AC ? The airflow over the condenser coil (from fans or vehicle moving forward at speed) keeps the refrigerant head pressure / temperature down. If the compressor completely shuts off (clutch de-energized) it may be from high head pressure from lack of air flow.

Clutch fans 99% of the time fail by the silicone fluid leaking out of them and can be a slow process.

If AC is barely getting cold at idle, check the refrigerant charge in the system. It is usually from the compressor not moving enough refrigerant through the system at idle speed.

 

[Dean2]

So Dutra - did you ever get this figured out or is the pickup still overheating?

 

[OCDTech]

The truck also has an electric fan that runs full time while AC is on, but are known to crap out or have a failed relay driving them.. Does that fan come on with the AC ? The airflow over the condenser coil (from fans or vehicle moving forward at speed) keeps the refrigerant head pressure / temperature down. If the compressor completely shuts off (clutch de-energized) it may be from high head pressure from lack of air flow.

Clutch fans 99% of the time fail by the silicone fluid leaking out of them and can be a slow process.

If AC is barely getting cold at idle, check the refrigerant charge in the system. It is usually from the compressor not moving enough refrigerant through the system at idle speed.

Yes, the electric fan running good. Probably that manual clutch, i forgot to mention the mileage, 117000