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Overheating Mistery

Discussion in 'Wrangler TJ (1996-2006)' started by Randalcor, Jul 12, 2019.

  1. Jul 12, 2019 at 1:04 PM
    #1
    Randalcor

    Randalcor [OP] New Member

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    4" lift, off road tires and rims. LED lighting.
    Hello,
    I recently bought a 99 TJ inline 6 automatic after owning a 97 inline 6 manual trans.
    I love these Jeeps even though they are a money pit. I just started having overheating problems with the automatic jeep. I have replaced the clutch, radiator, thermostat, temperature sensor, water pump, flushed the system, burped it and checked the cylinders.
    The Jeep will still overheat at random times. The last time it overheated I was on the highway doing about 60 mph. The niddle suddenly went from 210 to the red in a fraction of a second. I pulled over, turned it off for about 20 minutes and drove back home without it overheating again.
    Today I was driving down a street with traffic lights at every block, after about 10 blocks is suddenly shot up again to the red. I pulled over turned it off and back on and began to drive off in less then 30 seconds it was back to 210 degrees.
    I don't know what else to check or replace. Can someone help?
     
  2. Jul 12, 2019 at 1:42 PM
    #2
    Awrench

    Awrench Well-Known Member

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    You said changed clutch I will take that to mean FAN clutch... not elec fans

    A new radiator? same size or larger - I gotta ask.
    The shrouds are in place, OEM fan and its is pulling air, Thermostat* 195deg, Heater is not bypassed, There are NO codes (thinking gauge error).

    I would replace T'stat using a jeep component. Yeah it matters IDK

    Things that I have seen - wrong T'stat , wrong WP - if you have original look to see impeller direction and a stamped R on blades we may have to Dbl check new one to match.

    Are you loosing coolant?




    *Thermostat old world design, common part and yet quality problems IDK
     
    JKBob 25 and Randalcor[OP] like this.
  3. Jul 12, 2019 at 1:49 PM
    #3
    aggrex

    aggrex Well-Known Member

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    Tuffy>AEV>TTO>JW>STech>EVOcage>MagnaFlow>SpiderTrax>RockHard>TF>SpringTail>67design>Bolt>GPCA>Curt>
    Welcome @Randalcor ...wondering if there are clogged passageways. Performed reverse flush?
     
  4. Jul 12, 2019 at 4:06 PM
    #4
    Jim Beam

    Jim Beam Well-Known Member

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    I would have to vote for a pro flush out.
     
  5. Jul 13, 2019 at 12:30 PM
    #5
    Randalcor

    Randalcor [OP] New Member

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    4" lift, off road tires and rims. LED lighting.
    How do you do a reverse flush?
     
  6. Jul 13, 2019 at 12:36 PM
    #6
    Randalcor

    Randalcor [OP] New Member

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    99 wrangler
    4" lift, off road tires and rims. LED lighting.
    Hello,
    The Jeep is all original. I've replaced everything to original specs. Shroud is in place. I even replaced the catalytic converter.
     
  7. Jul 13, 2019 at 12:43 PM
    #7
    Randalcor

    Randalcor [OP] New Member

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    4" lift, off road tires and rims. LED lighting.
    I just figured out that the bottom hose could be a problem too by collapsing. Checked and it does have the coil inside to keep it from doing that.
    I found a video on You tube that talks about the harmonic balancer being a potential cause too. I've bought the past but haven't had time to swap it.
    Thanks for the help.
     
  8. Jul 13, 2019 at 2:28 PM
    #8
    aggrex

    aggrex Well-Known Member

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    Tuffy>AEV>TTO>JW>STech>EVOcage>MagnaFlow>SpiderTrax>RockHard>TF>SpringTail>67design>Bolt>GPCA>Curt>
    if the bottom hose has collapsed that might end this mystery. Otherwise there are some online videos of how pros flush or reverse flush.
     
  9. Aug 14, 2019 at 3:40 PM
    #9
    Jackryan12

    Jackryan12 Member

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    Are you SURE its overheating not just a bad gauge or sender
     
  10. Aug 14, 2019 at 7:52 PM
    #10
    JKBob 25

    JKBob 25 Well-Known Member

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    I'm subbed here. My 2000 had a 4.0 inline. And I had a running hotter than most, but not over heating issue. I think it's just a trait of the motor.
     
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