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Coolant Heat Storage Tank (CHS) Pump making Noise?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by RunnerCNY, Feb 28, 2014.

  1. RunnerCNY

    RunnerCNY Junior Member

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    I'm getting a noise that sounds like "woooooooooo" from the right front of the engine compartment when the outside temp gets below about 20F and I just start the car. The colder it gets, the longer the noise lasts.

    I suspect it's the pump that's part of the CHS. Just a very wild guess. The noise goes away when the car starts to warm up. No drive ability problems.

    Has anyone else experienced this noise? I live in central NY and winters are very cold. The noise is definably temperature related and occurs whether the car is still or moving (engine on). I have a 2005 with 175K miles. The dealer checked out the car after it sat overnight in frigid temperatures. Didn't see a problem and said it's an old car and noisy at start up.
     
    #1 RunnerCNY, Feb 28, 2014
  2. PriusGuy32

    PriusGuy32 Prius Driver Extraordinaire

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    My CHS pump only runs briefly when putting the car into READY mode or turning the car off. It runs for about 5 seconds and thats it. It does not continue running when the car is running/moving.

    I wonder if you are hearing your inverter coolant pump? Maybe its getting noisy/going bad? That runs all of the time, and when operating normally it sounds like an aquarium air pump... very light humming.

    Have you checked all of your coolant levels including the inverter cooling circuit?
     
    #2 PriusGuy32, Mar 1, 2014
  3. cwerdna

    cwerdna Senior Member

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    #3 cwerdna, Mar 1, 2014
  4. RunnerCNY

    RunnerCNY Junior Member

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    I've positively determined that the wooooo noise is from the tension pulley for the water pump belt. It's a very small pulley on the passenger side of the engine. It was cold this morning, so I started the engine with the hood up and used a long stick to isolate the noise. Now the question is whether I should replace the pulley since it only makes noise at start up after a very cold night.
     
    #4 RunnerCNY, Mar 16, 2014
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Is it possible that the noise is coming from the serpentine belt being slightly loose, and slipping at the pulley?

    I would suggest replacing the pulley and the serpentine belt when ambient temps warm up enough so that working on the car is not like being in an arctic survival adventure.
     
    #5 Patrick Wong, Mar 16, 2014
  6. RunnerCNY

    RunnerCNY Junior Member

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    I had the belt changed so it has to be the pulley. If it doesn't make noise in warm weather, should I replace the pulley. It's about a $50 part.
     
    #6 RunnerCNY, Mar 16, 2014
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I personally would eventually replace the pulley if the intent is to keep the car for another few years.
     
    #7 Patrick Wong, Mar 16, 2014
  8. RunnerCNY

    RunnerCNY Junior Member

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    I'll do it when the weather gets warmer. It's March 16 and 15 degrees tonight.
     
    #8 RunnerCNY, Mar 16, 2014
  9. RunnerCNY

    RunnerCNY Junior Member

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    I tried to get the old tension pulley out and couldn't. Eventually, I could move it up and down to tighten and loosen the belt. I think it's rusted into the slot and won't slide out. It may require an impact hammer. Any suggestions?
     
    #9 RunnerCNY, Apr 25, 2014
  10. socaldano

    socaldano Junior Member

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    soak where it attaches with WD40.
    If you can safely get to where it connects, heat it with a torch (like you use to sweat pipes)..
    Last month I was trying to get some corroded bolts out of the holes in car frame. Banged on them for an hour, no success.
    Heated them with a little propane torch, and one tap....pinnnnnnngggggg
     
    #10 socaldano, May 23, 2014
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I don't understand this comment.

    If you can move the pulley up and down, then you have loosened the large nut on the pulley, and you have loosened the bolt that provides tension on the serpentine belt. Fully remove the pulley nut so that the pulley can be removed and replaced.

    Look at the new part as that may give you a further clue about how to remove the old part.
     
    #11 Patrick Wong, May 24, 2014
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