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Overheating

Discussion in '4th Gen 4Runners (2003-2009)' started by orange01z28, Jun 29, 2024.

  1. Jun 29, 2024 at 12:02 PM
    #1
    orange01z28

    orange01z28 [OP] New Member

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    After 20 years with no issues my V6 2003 started having issues on a roadtrip.

    Filling it with coolant from time to time got me all the way home. As long as I was moving it was fine

    Then I had it in a shop for a pressure test and a flush. There were no leaks but the fan clutch was replaced.

    this seemed fine until I took it out today, after a 1.5 hour drive it started getting hot again, then it had a full boil over and was staying hot. It dropped into normal range a couple times but finally got hot enough that I pulled over and am waiting for a tow right now

    The water pump has been replaced in its lifetime, but the radiator has not. I also noticed it getting much cooler than it should be when not under load, like a bad thermostat or something

    should I go ahead and replace the whole radiator or could this be a thermostat problem? It takes literal hours of driving to recreate the problem.
     
  2. Jun 29, 2024 at 12:35 PM
    #2
    Thacrow

    Thacrow New Member

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    Speed holes
    Replace the thermostat and see if that works?

    The thing that opens and closes to let's water flow through the engine from the radiator based on temperature might have gone out.

    Happened one time to a car I used to have.
     
    orange01z28[OP] likes this.
  3. Jun 30, 2024 at 4:56 AM
    #3
    Buckaroo

    Buckaroo New Member

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    Agree with thermostat replacement. Would also replace radiator cap if you have not done so in the last couple of years. Two inexpensive things you can do yourself. Also, make sure your engine coolant is the correct mix - Toyota Pink is premixed so if you are adding that you are good. Then see how it goes regarding radiator or water pump replacement.
     
    Last edited: Jun 30, 2024
  4. Jun 30, 2024 at 5:12 AM
    #4
    ChessGuy

    ChessGuy New Member

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    Too many..... Performance: • Magnusum Supercharger • Gibson exhaust with dual black tip • Pedal Commander * PowerBrakes • Suspension – Old Man Emu BP-51 front and back with Medium load coils • Tires: AT3 Faulken Wildpeak – 285/70/17 • Wheels: Relations Race Wheels, RR7-H with -12 offset • Full roof rack and ladder by Westcott Design (removed the stock Yakima basket) • Molle storage panels by Rago fabrication • Front light brackets by Rago • Illuminator light bracket by Rago (roof rack location) Lights • Morimoto front and back with sequential signals • Morimoto fog lights and side mirrors with sequential signals • 40” Baja design light bar for roof rack • 20” S8 Baja design driving combo (winch location) • Squadron sport baja design ditch lights • S2 Chase lights by baja designs (mounted on roof) In the bay: • Odyssey 34-PC Battery • SDQH Aluminum billet battery terminals and bracket • Switch Pro 9100 with aluminum tray • Anytime front and back camera • ARB twin compressor Recovery & Protection: • Smittybilt X20 synthetic rope winch • Factor 55 fairlead and flatlink • Southern Style Off-road (SSO) low profile bumper • SSO stage 2 high clearance wings • Weekend warrior recovery kit by treaty oak • RCI – skid plates – entire vehicle + catalytic converter protection wings Interior: • Nano Ceramic IR – Avery Dennison Window tint – all windows • Several phone mounts • Upgraded Rear Hatch lift gate struts (ladder is heavy) • Boom blaster horn switch (featuring La cucaracha)
    I would do radiator as well. You might have a restriction inside, like debris or residue over the years that has gone stuck and impossible to see.
     
    orange01z28[OP] likes this.
  5. Jun 30, 2024 at 3:52 PM
    #5
    orange01z28

    orange01z28 [OP] New Member

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    I'm definitely leaning this way, I might just do the water pump while i'm at it
     
  6. Jun 30, 2024 at 4:25 PM
    #6
    Lost Woods

    Lost Woods New Member

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    Before you just throw money at a radiator, get an infrared thermometer and start spot checking. If you have an obstruction, you should have cold spots. Thermostat stuck open sounds about right for the symptoms assuming the fan is good.

    If you're paying someone to do this, just say overheating and the fan clutch is new. Don't ask for parts, it's not their responsibility to make sure something is defective before replacing it.
     
    orange01z28[OP] likes this.
  7. Jul 17, 2024 at 9:49 AM
    #7
    orange01z28

    orange01z28 [OP] New Member

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    3" Icon Stage 3 Lift Metaltech rear control arms Metaltech bump stop extensions 35 x 11.5 Falken Wildpeak RT01
    At the end of the day, the thermostat falling to pieces was the likely culprit

    IMG_9664.jpg

    However, while I was at it, I had my shop put in a new radiator as well as rebuild the fan clutch by changing the oil they come with and putting in some thicker stuff along with optimizing the temp the clutch will start to move air.

    They do this with 80 Series a lot and it really helps

    Everything is running perfect now. I went wheeling last weekend and spent the whole day with teh AC on. Temp was always exactly where it was supposed to be
     
    RonT4R and gkomo like this.

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