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Gurgling, swishing, liquid noise behind dash noticed after rapid engine state changes - 2008 Prius

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by puzzlefighter, Jul 21, 2016.

  1. puzzlefighter

    puzzlefighter Junior Member

    Joined:
    Jul 21, 2016
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    Location:
    Chicago, IL
    Vehicle:
    2008 Prius
    Model:
    N/A
    I've got a gurgling, swishing noise issue on my '08 Prius. I hadn't heard or noticed this noise prior to last weekend, over which I had my water pump (two weep hole), PCV valve, belt, and 3-way coolant flow control valve replaced (engine code p1121). The mechanic replaced the drained coolant with new SLL pink coolant I bought from the Toyota dealer. My Prius has 186,000 miles on it and the p1121 code had probably been active for about 18 months preceding the replacement. The check engine light is now gone and has yet to return, but I am now hearing a swishing noise from behind the dash area at times. It is most audible during the 1st drive of the day with the A/C on. As the vehicle runs through its warm up cycles, I'm puttering to the end of my subdivision. This is the first opportunity for my car to come to a complete stop. When I do, and I push the pedal hard down, the combustion engine basically comes to a stop; and it is at this time that the gurgling and swishing noise is emitted. After this, it is possible to be heard upon subsequent accelerations following a complete stop, but much less audibly. I do have some extra clean coolant, so I will try taking steps to remove any potential air caught in the system, but I'm not sure if there might be some other cause. Anyone got a different idea as to the cause?

    Possibly related, and prior to the repair work mentioned above, I recently started hearing a sort of ghost moaning-groaning noise when I would turn on and turn off my car. I thought it might be related to the failure for coolant to be pushed/pulled to the thermos (i.e. related to p1121), and this noise is what prompted me to get the p1121 code finally addressed. However, the sound remains. Anybody know what might be causing this?
     
  2. bikes4u

    bikes4u Member

    Joined:
    Sep 8, 2015
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    Location:
    indianapolis
    Vehicle:
    2005 Prius
    Model:
    IV
    Usually an indication of air in the system. Did you turn the heat on high and drive around for a while? may help get air out of heater core
     
  3. andrewclaus

    andrewclaus Active Member

    Joined:
    Sep 15, 2009
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    Location:
    Golden, CO
    Vehicle:
    2007 Prius
    If your mechanic is not experienced in the Prius coolant system, and does not have the specialized tools needed to bleed the system, he/she probably got it wrong. Your coolant level is low, and that's not good. You need to get it to someone who has the tools and knowledge to bleed it, or read the threads here about it and DIY, ASAP.
     
  4. puzzlefighter

    puzzlefighter Junior Member

    Joined:
    Jul 21, 2016
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    Location:
    Chicago, IL
    Vehicle:
    2008 Prius
    Model:
    N/A
    Yeah, I guess I figured on that. After taking the DIY path and filling, running, refilling, repeating, it seems to be OK now, though I haven't completely filled the reservoir at this point. Is that the expected status? To have a 100% full reservoir + a seemingly full radiator?
     
  5. andrewclaus

    andrewclaus Active Member

    Joined:
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    Location:
    Golden, CO
    Vehicle:
    2007 Prius
    Have you manually cycled the CHRS and does it sound healthy? Have you used the upper radiator bleeder valve? Even after doing that, it took several drive cycles for my level to stabilize at full, both in the radiator and reservoir. (BTW, have you figured out you can check the radiator by only removing two of the splash shield fasteners? Handy trick.)