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Gurgle, weak heater.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Marcilla Smith, Oct 11, 2024.

  1. Marcilla Smith

    Marcilla Smith Active Member

    Joined:
    May 14, 2018
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    Location:
    Raleigh, NC
    Vehicle:
    2011 Prius
    Model:
    N/A
    2011 Prius with a 2013 motor installed 6 months ago along with new radiator and water pump.

    Motor started making the dreaded "death rattle," and I was like, "you gotta be kidding me - how can I need a head gasket already???"

    Back it went to ISH in South FL who replaced the spark plugs and cleaned the EGR. He said the spark plugs showed no signs of coolant intrusion.

    On my way back to NC, I got a "triangle of death" with "check hybrid system" when I pulled off 95 in Daytona to my cousin. Checking the codes, it seemed the water pump went so I limped it in electric to my cousin's place, where I replaced the water pump (with a new one from the dealer).

    When I got back to Raleigh and figured all was well, only to have the rattle start again! ISH had me to take the o-ring from the coolant reservoir. This stopped the rattle, which he said sounds like it is because there is too much pressure in the coolant system.

    He must be on to something, because when I've tried to bleed the coolant to stop the gurgling (from behind the dash), the coolant foams up into the reservoir :: eye roll ::

    Now, I've read could be due to a head gasket leak, so I got the kit at Autozone, and I'm to say that the liquid stayed bright blue - no exhaust.

    So is the problem as simple as air is getting into the coolant line, and if so, how do I make it stop?
     
    #1 Marcilla Smith, Oct 11, 2024
  2. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
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    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Relieving the coolant pressure reduces coolant pushing into the cylinder as the engine cools off. It does not solve a hg leak.

    Instead combustion gasses push into the coolant but usually not continually. Because of the short term nature, typically at engine startup, the coolant gas tests don’t work. Technically there is not enough time to saturate the coolant.

    A borescope test is needed. I would go to the shop who changed your engine.
     
    #2 rjparker, Oct 11, 2024
    Last edited: Oct 11, 2024
    Marcilla Smith likes this.
  3. BiomedO1

    BiomedO1 Senior Member

    Joined:
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    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    I'm assuming that 2013 motor was a used motor. That's the gamble your taking when not replacing with a rebuilt motor. Since you also replaced the radiator & water pump, I'm also assuming a head gasket sealer product(s) was used on the old 2011 engine. You may also want to check the switch valve, if your car is equipped with one.
    Removing that O-ring will prevent your cooling system from pressurizing, making it more difficult to purge air bubbles out of your cooling system. This DOES NOT fix the head gasket issue - coolant seeping into the combustion chamber and hot exhaust gases pushing into your cooling system. The bad new is that it will worsen over time. Right now, as your engine warms up and expands - it's sealing the leak. That's why the exhaust gas coolant test is currently negative. As the problem worsens, that test will eventually turn positive.

    sorry for the bad news.....

    If you do a compression & leak-down test when the engine is stone cold, you'll see the leak. If you do the same test with the engine warmed up, it'll probably pass the test.
     
    #3 BiomedO1, Oct 11, 2024
    Marcilla Smith and Mendel Leisk like this.
  4. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
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    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    No coolant switch valve on a gen3
     
    #4 rjparker, Oct 11, 2024
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