2016 cummins isx15 high oil temp

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by scooter1965, Feb 11, 2024.

  1. scooter1965

    scooter1965 Bobtail Member

    3
    0
    Feb 11, 2024
    0
    Oil temp on truck always ran around 210 when going down the road, water temp stayed around 190 unless pulling hill the water would increase to 205, and oil would generally. Run up to 225 to 230. It started showing oil up in the coolant reservoir from a seeping cooler or cooler gasket. Flushed the system really well. Changed out to a new cooler and all new gaskets, now oil temp is running 225 going down the road empty, water temp stays at 190. If pulling hard like Jelico mountain in TN, oil temp will almost reach 250. Does anyone have any idea how to get oil temp to run cooler or maybe a issue with engine i may have?
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. Judge

    Judge Road Train Member

    11,146
    71,319
    Mar 19, 2014
    Arkansas
    0
    1. Reasons for high oil temperature, System Issues: The engine oil temperature is regulated, in part, by the cooling system. If there are problems with the coolant system, such as a malfunctioning radiator, water pump, or thermostat, it can result in inefficient cooling. Inadequate cooling can lead to higher engine oil temperatures.
    2. Insufficient Lubrication: If the engine oil level is low or if there is a problem with oil circulation, such as a malfunctioning oil pump or clogged oil passages, it can lead to inadequate lubrication. Insufficient lubrication causes increased friction and heat generation, resulting in elevated oil temperatures.
    3. Engine Overheating: Engine overheating, often due to issues with the cooling system or components like a malfunctioning radiator fan or a blocked airflow, can directly affect the oil temperature. When the engine overheats, the excess heat transfers to the oil, causing an increase in oil temperature.
    4. Oil Viscosity: Using engine oil with a viscosity grade that is not suitable for the operating conditions or outside the recommended range can result in higher oil temperatures. Oil that is too thin or too thick for the engine's requirements may struggle to dissipate heat efficiently, leading to elevated oil temperatures.
     
    Icanfixit Thanks this.
  4. Icanfixit

    Icanfixit Bobtail Member

    16
    8
    Dec 21, 2023
    Minnesota
    0
    The older isx used a thermostat for the oil cooler. Not so sure about the newer ones, but the reliefs might be something to check out.
    Also, what is the actual oil temp? You can only trust a gauge to within 10%.
     
  5. scooter1965

    scooter1965 Bobtail Member

    3
    0
    Feb 11, 2024
    0
    I changed the oil cooler when it started leaking, and oil thermostat the next weekend due to oil temp running warmer than it did before problem with the cooler thinking it would help, but never changed anything, the oil never reaches 250 but gets close. Engine runs 220 to 225 degrees with empty tanker, loaded it runs maybe 230 till you get into long pull. Then it will come up to 240 to 249. Can't think of a reason that the oil temp would change just because of changing oil cooler..
     
  6. scooter1965

    scooter1965 Bobtail Member

    3
    0
    Feb 11, 2024
    0
    Also changed the oil temp sensor. Would the oil bypass valve have anything to do with this problem if it is malfunctioning?
     
  7. sirrepairsalot

    sirrepairsalot Bobtail Member

    46
    16
    Aug 9, 2018
    0
    Check that Sensor compared to real temps from a probe gun. Bet you have a biased sensor giving you issues.
     
  8. sirrepairsalot

    sirrepairsalot Bobtail Member

    46
    16
    Aug 9, 2018
    0
    Also if servicing the oil cooler, pull the thermostat OR have it tested. Me I like a problem free system and less parts to rely on.
     
  9. Goodysnap

    Goodysnap Road Train Member

    3,500
    8,375
    Jul 12, 2017
    0
    The only thing the oil bypass valve does is opens to pass oil by the oil filter if it becomes clogged. So should have no effect on high oil temp.
     
  10. little cat 500

    little cat 500 Road Train Member

    1,950
    1,004
    Jan 17, 2010
    Abbottstown PA
    0
    sounds normal i just sold one of the boat anchors run the same temps as you say
     
    Diesel Dave Thanks this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.