Thanks Thanks:  6
Likes Likes:  20
Results 1 to 6 of 6

Thread: Engine Temp Fluctuations - Cummins 6.7L?

  1. Top Of Page | #1

    Engine Temp Fluctuations - Cummins 6.7L?

    What would be causing my truck temperature to fluctuate at average operating temp when driving down the road?

    It fluctuates up to 4 degrees above normal operating temp; I don’t understand why it would fluctuate below normal operating temp 4 degrees when driving normally.


    Sent from my iPhone using Tapatalk


  2. Thanks IGOTACUMMINS, SyN thanked for this post
    Likes watersupply189, IGOTACUMMINS, SyN, AK Bob liked this post
  3. Top Of Page | #2
    Aj Grubb's Avatar

    User Info Menu

    Re: Engine Temp Fluctuations - Cummins 6.7L?

    My truck does this as well.

    I can't remember if it always has or not.

    I have convinced myself that it is just the thermostat opening and closing, causing the slight oscillation in temp.

    I'm not worried about it unless it overheats or refuses to get to operating temp.


  4. Thanks IGOTACUMMINS thanked for this post
    Likes watersupply189, IGOTACUMMINS, SyN, AK Bob liked this post
  5. Top Of Page | #3
    MOD watersupply189's Avatar

    User Info Menu

    Re: Engine Temp Fluctuations - Cummins 6.7L?

    My truck does the same thing.

    Your thermostat opening and closing, plus the fan clutch, are engaging and cooling it down; this is why you see the temp gauge going up and down.

    I wouldn’t be concerned unless your gauge is reading extraordinarily high and not cooling down.


    2016 Ram Laramie 3500, G56, 6.7, CC, 4x4

    2016 RAM 3500 4x4 Laramie Crew Cab
    Cummins,G56, Rough Country level, Morimoto LED fog lights, LED headlights, Lund Attitude Steps sprayed with Line-X, DRL's Activated, 35x12.50R18 Falken Wildpeak ATW3, Fuel Vapor Wheels Matte Black w/Dark Tint, A.R.E. Truck cap and swing boxes

  6. Thanks IGOTACUMMINS thanked for this post
    Likes IGOTACUMMINS, SyN, AK Bob liked this post
  7. Top Of Page | #4
    Rambling Rump Ranger! SyN's Avatar

    User Info Menu

    Re: Engine Temp Fluctuations - Cummins 6.7L?

    Agree with all the above - (Thoughts).

    Mine does it as well - digital electronics are
    Not complaing - glad I have the information in front of me (Don't know how accurate it actually is though) but better then driving blind.

    2017 Bighorn (Delmonico Red & Chrome) CC-HD2500-4WD-6.7L-3:42w/Anti-Spin
    Oil: -SHELL- Rotella T6 5W-40 & T5 15W-40 combo w/LF16035
    68RFE/BW44-46/Power Steering: -Red Line- C+ ATF
    Frontend & Rearend: -Red Line- SAE GL-5 75W-90NS
    Many Small Mods: Interior & Exterior
    Mileage: 28,541

  8. Thanks IGOTACUMMINS thanked for this post
    Likes IGOTACUMMINS, AK Bob, watersupply189 liked this post
  9. Top Of Page | #5
    I WILL STAND! AK Bob's Avatar

    User Info Menu

    Re: Engine Temp Fluctuations - Cummins 6.7L?

    Perfectly normal, as stated above, the engine coolant temperature will fluctuate slightly as the thermostat tries to maintain a normal operating temperature.

    2014 RAM 3500 (Aisin) 3.73 4X4 Limited Crew Cab Long Bed DRW. Oil Bypass Filter, Fuel Filtration Kit, Cold Air Intake, City Diesel Actuator and 50 Gallon Aux Fuel Tank.

  10. Thanks IGOTACUMMINS thanked for this post
    Likes IGOTACUMMINS, watersupply189, SyN liked this post
  11. Top Of Page | #6
    BuckMeister's Avatar

    User Info Menu

    Re: Engine Temp Fluctuations - Cummins 6.7L?

    Once the stat initially opens mine will constantly go between 186-203.

    A slow build-up and then a sudden drop.


  12. Likes watersupply189, AK Bob, Tian-Zen liked this post

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •