2.5L Coolant Temp Sensor Replacement

Discussion in 'General Motoring' started by jmcgill, Apr 11, 2006.

  1. jmcgill

    jmcgill Guest

    I have to replace the coolant temp sensor on my 2.5L engine. I may be
    an idiot for asking, but do I have to bleed the cooling system after I
    take out this old sensor, or can I just plug in the new one with no
    adverse affects (assuming that the sensor was the only problem)?

    Thanks,

    Joe
     
    jmcgill, Apr 11, 2006
    #1
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  2. jmcgill

    kmatheson Guest

    There was no mention of what model you have your 2.5 in. On the
    Spirit/Acclaim, the radiator sits lower than the thermostat housing, so
    it is a good idea to bleed the system anytime it is opened, other than
    the radiator cap. There is a bleeder plug on the thermostat housing for
    this purpose.

    -Kirk Matheson
     
    kmatheson, Apr 11, 2006
    #2
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  3. with kma on this one, bleed the system after replace. The therm.
    housing traps air and has to be bled anytime the system is
    de-pressurized, sigh.
     
    Knifeblade_03, Apr 11, 2006
    #3
  4. jmcgill

    jmcgill Guest

    I have a 1988 Aries.....

    I guess I'll have to wait to get home to do the procedure.

    Thanks,

    Joe
     
    jmcgill, Apr 11, 2006
    #4
  5. If ya have a bleed plug on the therm. housing, you'll see it. It a
    simple deal, run the engine to ooperating temp., loosen the bleed valve
    to let the air escape until only coolant runs out of it.

    1] Try to open the valve before any engine run, make sure it hasn't
    frozen up.
    2] Be careful not to open it up too much, too much coolant may spray
    onto the serpentine belt, not a good thing. Also, ya may get some
    steam coming out, so watch your hands.
    3] Keep eye on coolant level in reservoir tank.

    Hope this helps. I surfed autozone's site for your model, no listing
    of a bleeder valve in the therm. housing, but if it there, it easy to
    spot.
     
    Knifeblade_03, Apr 12, 2006
    #5
  6. jmcgill

    maxpower Guest

    --

    Ummmmm.. technically you can use the coolant sensor as the bleeder, let the
    engine warm up and leave the sensor loose, it is just about the same height
    as the bleeder and works just the same.....

    Glenn Beasley
    Chrysler Tech
     
    maxpower, Apr 12, 2006
    #6
  7. jmcgill

    jmcgill Guest

    Now, looking at the thermostat housing, there are two allen wrench
    fittings: one on top of the housing, and one on the side near the
    coolant sensor. Which one of these would I use to bleed the system
    once I get the new sensor in?
     
    jmcgill, Apr 12, 2006
    #7
  8. jmcgill

    maxpower Guest

    --

    use the sensor that you just replaced to bleed the system
     
    maxpower, Apr 12, 2006
    #8
  9. jmcgill

    jmcgill Guest

    I've never done anything like this, so forgive me for sounding
    dumb...but do I replace the sensor with the engine cold, and leave the
    new one loose, and THEN start up the engine and allow it to warm up?
    Won't there be antifreeze everywhere?
     
    jmcgill, Apr 13, 2006
    #9
  10. jmcgill

    maxpower Guest

    --

    if you do it cold, leave the radiator cap on while you remove and install
    the new one, if your afraid to loose coolant, drain some of it down!!

    Glenn Beasley
    Chrysler Tech
     
    maxpower, Apr 13, 2006
    #10
  11. It depends. If your antifreeze is properly mixed then it takes a lot
    of heat for it to start boiling in an unpressurized system. By then the
    major air bubbles will have worked their way to the bleed hole
    and you will have poured in more antifreeze into the sensor hole
    to displace the air, and screwed in the sensor. It takes time for
    heat to work it's way into the coolant from the cylinder walls.

    Once the water jacket gets hot enough for the antifreeze to boil
    in an unprsssurized system, then when that happens, yes a lot of
    antifreeze will want to come out of the hole.

    You should have at least 5 minutes of time before this starts
    happening.

    Ted
     
    Ted Mittelstaedt, Apr 14, 2006
    #11
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