Forum Discussion

Licreek's avatar
Licreek
Explorer
Jul 16, 2018

Cat Diesel engine temp

Hello all. I have a 36’ diesel pusher with a 275hp cat engine. Also I’m pulling a small car on a tow dolly. It’s mid July and I’m moving through Texas headed to indiana. This is my first run in 90+ ambient temps. I am noticing my temp gauge moving from about 5/8 to 3/4 when pulling a fairly light and short grade. The gauge has not moved to the red but if this were a gas engine I would say it’s running on the hot side. Iv never owned a diesel so my question is does this sound normal? Im afraid my rig will never make it through the Rocky’s. Also if the gauge moves close to the red can this cat engine handle it or should I be pulling over quick for a cool down. By the way it’s a 1999 year with 90k miles and all maintenance done. Thank you for any info. Safe travels, Lee
Class A
  • gswcgi's avatar
    gswcgi
    Explorer
    Jul 16, 2018
    I have a different CAT than you do (a 3126E 330 HP version 2003). I tow a 5,000 lb Nissan XTerra behind a 36' Safari Cheetah RV. Now have 55,000 miles on the RV and live in Reno, NV where everything starts at 4,500' and goes up from there. Many, many times I have climbed 0ver 8,000+' in the summer and my temp gauge never moves over normal range. You need to start by checking your thermostats, belt tension and the water pump and its belts as well as possibly draining and replacing your radiator fluid. Remember, most CAT and diesel engines also use the fluid to cool the tranny. Try washing the radiator, charge air cooler and tranny cooler. I wash mine after every trip to clear out the road junk etc. Your CAT should not get hot pulling your load.
  • Big_Katuna's avatar
    Big_Katuna
    Explorer II
    Jul 16, 2018
    I concur with Wolfe. My 05 doesn’t budge above normal whether it’s on flat road or up 7% grades in West Virginia.
  • Licreek's avatar
    Licreek
    Explorer
    Jul 16, 2018
    Thanks Bill. I just looked around under the dash and left firewall around the fuse panel and no luck finding a obd port. Maybe someone out there knows if a 1998 model has obd ?
  • Trackrig's avatar
    Trackrig
    Explorer II
    Jul 16, 2018
    I would highly recommend you buy a Scangauge since you have idiot gauges. This will give you your exact temperatures and a lot of other information.

    It should work on your MH, but since it's a 1999, make sure it has the OBDII Port before buying. It's well worth the $160.

    Amazon

    Bill
  • wolfe10's avatar
    wolfe10
    Explorer
    Jul 16, 2018
    Your coolant temperature should NOT rise about thermostatic control on minor grades.

    Have you cleaned the FRONT of your CAC?

    Have you checked the tension on the water pump belt?

    How old are the thermostats (Caterpillar calls them regulators)?

    What coach do you have?

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