Engine temperature rises in stop and go traffic

Tiny
SEMINOLE31757
  • MEMBER
  • 2010 DODGE RAM
  • 4.7L
  • V8
  • 2WD
  • AUTOMATIC
  • 183,000 MILES
My truck (1500) has both an electric fan and the unit attached driven by the accessory belt. While driving at highway speeds the temperature stays in the normal range of 199-206 degrees, but as soon as I stop the temperature begins to rise. I can turn on the heater setting the fan on the high setting and the temperature will drop, long enough for me start moving again. It has gotten up to 220 and as I drove off the temperature would drop, but I would have expected the fan clutch to be fully engaged, but this was not the case. Also, I would have expected the electric fan to start even though the AC was not on as a sort of back up to the apparent failed belt driven fan, but the electric fan did not start either. Is it possible that the issue is simply a failed fan clutch and I am mistaken in thinking the electric fan? Which sit in front of the belt driven fan, should come on if the engine starts to overheat.
Monday, August 27th, 2018 AT 4:13 AM

11 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good morning.

This does sound like a fan clutch issue.

I would also make sure there is no dirt or debris in the radiator preventing air flow to cool down the coolant.

Roy

Caution: If the viscous fan drive is replaced because of mechanical damage, the cooling fan blades should also be inspected. Inspect for fatigue cracks, loose blades, or loose rivets that could have resulted from excessive vibration. Replace fan blade assembly if any of these conditions are found. Also inspect water pump bearing and shaft assembly for any related damage due to a viscous fan drive malfunction.

Note: Viscous Fan Drive Fluid Pump Out Requirement: After installing a new viscous fan drive, bring the engine speed up to approximately 2000 rpm and hold for approximately two minutes. This will ensure proper fluid distribution within the drive.

1. Install fan blade assembly (2) to the viscous fan drive. Tighten the bolts to 24 Nm (18 ft. Lbs.) Torque.
2. Position the fan shroud, electric cooling fan and the fan blade/viscous fan drive assembly (2) to the vehicle as a complete unit. See: Radiator Cooling Fan > Removal and Replacement > Electric Radiator Fan - Installation
3. Install the fan shroud.
4. The thermal viscous fan drive/fan blade assembly is attached (threaded) to the water pump hub shaft. Install the fan blade/viscous fan drive assembly to the water pump by turning the mounting nut counterclockwise as viewed from the front. Threads on the viscous fan drive are LEFT-HAND. A 36 MM Fan Wrench (1) should be used to prevent pulley from rotating. Tighten mounting nut to 50 Nm (37 ft. Lbs.).
5. Connect the negative battery cable.
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Monday, August 27th, 2018 AT 5:44 AM
Tiny
SEMINOLE31757
  • MEMBER
  • 6 POSTS
Should I be concern the electric fan never came on? The failed clutch theory makes sense; I am just unsure if the electric fan should have started or if it just runs when the AC is on to cool the refrigerant in the condenser.
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Monday, August 27th, 2018 AT 7:38 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
The electric fan should come on when the AC system is activated and the high side pressure reaches 150 lbs.

Roy
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Monday, August 27th, 2018 AT 8:11 AM
Tiny
SEMINOLE31757
  • MEMBER
  • 6 POSTS
Roy,
Do you know of an online repair guide that would walk me through the clutch removal? I am fairly handy with tools, but over the years I have learned a lot of blood, sweat, and at time costly tears can be saved by doing the job correct the first time. Thanks
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Monday, August 27th, 2018 AT 11:43 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
I gave you the procedure above.

Other than that, you can get daily access to Alldata or Mitchel repair guides online.

Roy
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Monday, August 27th, 2018 AT 11:47 AM
Tiny
SEMINOLE31757
  • MEMBER
  • 6 POSTS
Roy,
I have additional information. Yesterday I took a closer look at my truck and discovered the low fan shroud was not re-installed correct a few weeks ago after a water pump installation. My guess is the fan is pull air around and not through the radiator. My fan will currently turn close to a 1/4 turn with the engine off by hand, so I am assuming the clutch is holding and the issue is more related to the damage cause to the shroud by my local garage. Do you think the missing lower shroud would cause the stop and go heating issue?
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Tuesday, August 28th, 2018 AT 12:53 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Yes, the shroud has to be intact. Fix that first.

With the engine running, AC on, rev it up to 1,500 rpm. Can you hear the fan clutch engage?

Roy
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Tuesday, August 28th, 2018 AT 1:02 PM
Tiny
SEMINOLE31757
  • MEMBER
  • 6 POSTS
So, I took the truck back to the shop and they installed a new lower shroud. They informed me my fan clutch was in fact bad. I am not big on co-incidents, but they believe my clutch went out a week after they changed the pump. My concern is at some point the fan was jammed up against the lower shroud and could not turn. Could this potentially damage the clutch since the input shaft was turning but the fan itself could not turn due to being jammed by the damaged lower shroud?

They are willing to replace the clutch, but I believe in being honest and would not expect a shop to loss money on a job if it is just normal wear. I had them inspect the fan and there was no sign of damage so it appears the shroud got caught on start up and the fan only turned a rotation of two.
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Wednesday, August 29th, 2018 AT 8:13 AM
Tiny
ASEMASTER6371
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  • 52,796 POSTS
Yes, I agree. I bet the lower shroud trapped the fan and failed the clutch.

Do you have it back and is it okay?

Roy
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Wednesday, August 29th, 2018 AT 8:23 AM
Tiny
SEMINOLE31757
  • MEMBER
  • 6 POSTS
They are ordering OEM parts because I would not accept aftermarket. Should be repaired tomorrow. Thanks for the great advice.
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Wednesday, August 29th, 2018 AT 9:19 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
You are welcome.

Always glad to help.

Roy
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Wednesday, August 29th, 2018 AT 9:57 AM

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