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sloshing sound when restarting

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by stephen2002, May 31, 2013.

  1. stephen2002

    stephen2002 Junior Member

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    Vehicle:
    2007 Prius
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    I've been noticing a new sloshing noise coming from the ICE when it restarts from a stop that goes away after a few seconds of running. It doesn't make the noise when the engine is cold (first start) and after a few times of making the sloshing noise it doesn't make the sound for any more starts until after it has cooled back down. Sometimes it doesn't make (or I don't notice) the noise at all. The various fluid levels are normal and nothing seems to be leaking. Any ideas as to what this noise would be?

    Full history of recent coolant system repairs:
    A few weeks ago I had some work done that involved the ICE coolant system. I have about 70k on a 2007 Prius. First I had the coolant recovery pump replaced (it was squeaking). After the second or so time the new pump ran I got a check engine light. The dealer said that the coolant valve got stuck open and had to be replaced. Did one cause the other ... I don't know ... it seems like an awful suspicious coincidence but they didn't mention anything. After the valve was replaced they gave it back to me and on the way home the car would throw the high temperature alert up when accelerating for more than about 5 seconds and then immediately clear the alert when I backed off the accelerator so I brought it right back. They said that there was some air left in the system from the repair that they had to get out. They gave it back and it's been running fine since other than the noise.
     
    #1 stephen2002, May 31, 2013
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Two
    1. See if the cabin heater works.
    2. When you turn the heater on do you hear sloshing?

    If your answer is no to #1 and yes to #2, then there is still air in the engine coolant loop.
     
    #2 Patrick Wong, May 31, 2013
  3. stephen2002

    stephen2002 Junior Member

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    Cabin heater works. After the engine warmed up I cycled it on an off for a bit and heard sloshing for the first couple of cycles but that diminished as I continued.

    Is there anything I can do to get the air out or should I bring it back to the dealer?
     
    #3 stephen2002, Jun 1, 2013
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Vehicle:
    2015 Prius
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    Two
    Yes. What you can do is to buy a gallon of Toyota Super Long Life Coolant. Then remove the black plastic cover over the radiator, held on with six plastic fasteners that look like Philips screws. To remove a fastener, rotate it with a screwdriver while exerting upwards pressure on the cover. The fastener will pop out.

    Now you have access to the radiator cap. Remove the cap and fill the radiator fully with SLLC. Remove the cap for the radiator overflow container and fill that to the top line. Replace both caps.

    Start the car. Set the heater control to MAX HEAT and run the fan at a high speed. Rev up the engine to 2,000 RPM or so until it has warmed up. Then rev up to 4,000 RPM repeatedly, over 10 minutes or so. That should promote engine coolant circulation and get the air out.

    Then turn off the engine. Let the system cool down. Remove the two caps and fill as needed with SLLC. If you needed to add substantial fluid, you may want to repeat the process.

    When you are done, reinstall the black plastic cover and six plastic fasteners.
     
    #4 Patrick Wong, Jun 1, 2013
  5. stephen2002

    stephen2002 Junior Member

    Joined:
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    Vehicle:
    2007 Prius
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    N/A
    So I gave it a try running the heater on max and revving the engine by leaving it in park and pushing on the gas. I noticed that it wouldn't maintain higher RPMs. If I pushed down the accelerator to get it out of idle it would rev up, the car would lurch a bit, and then rev back down on its own. If I held the accelerator in the same spot it just kept going up and down on its own in a pretty regular interval. I don't have any additional instrumentation so I don't know what the RPMs were but I was holding the accelerator about half way. No warning lights or odd noises but it doesn't seem like that would be normal behavior, so I stopped the procedure. There aren't any problems when driving and I still have the sloshing.
     
    #5 stephen2002, Jul 5, 2013
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