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2008, weird noise under hood, drivers side

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by les.warden, Apr 17, 2019.

  1. les.warden

    les.warden Junior Member

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    2008 Prius. We purchased new. I have this strange noise under the hood, on the drivers side. Almost sounds like something trying to open, close, or engage then stopping, then retrying, etc. Over and over. I don’t know if it does it ALL the time, but definitely when I start it up. Always done maintenance on the car. Just had new struts, tires, plugs, oil and all filters changes. It was doing it before any of this though. It has 134,000 miles and still runs like a champ. I have a small video with the noise that I’m trying to figure out how to upload. I’ll upload soon as I figure that out. Any help in that area too is appreciated.
     
    #1 les.warden, Apr 17, 2019
  2. JC91006

    JC91006 Senior Member

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    It probably is a bad 3 way valve, it'll be much louder when you open the hood
     
    #2 JC91006, Apr 17, 2019
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  3. les.warden

    les.warden Junior Member

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    Here’s the video



    iPhone
     
    #3 les.warden, Apr 17, 2019
  4. les.warden

    les.warden Junior Member

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    It is louder when the hood is open. You can slightly hear it in the cabin.


    iPhone ?
     
    #4 les.warden, Apr 17, 2019
  5. bisco

    bisco cookie crumbler

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    or else an hvac vent door
     
    #5 bisco, Apr 17, 2019
  6. les.warden

    les.warden Junior Member

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    Went on YouTube to search and ran across the replacement of a coolant valve. Seems to be in the same area of the noise. The video didn’t indicate a noise but said an error code (P112?) led them to the replacement. They also said there was a TSB on this very part.

    Assuming this is the part creating the noise and going bad, does the TSB mean Toyota should replace it at their expense?

    It seems like it’s costly to have them replace it but a major PIA to do it yourself.

    Maybe this is the valve being mentioned on my car??
     
    #6 les.warden, Apr 17, 2019
  7. les.warden

    les.warden Junior Member

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    Can you expand on where a noise from that part might be heard?
     
    #7 les.warden, Apr 17, 2019
  8. bisco

    bisco cookie crumbler

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    under the dashboard. the doors are motorized, but sometimes stick and keep trying to move.
    the valve is more likely though
     
    #8 bisco, Apr 17, 2019
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  9. les.warden

    les.warden Junior Member

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    Finally decided: It’s a noise, could be the 3-way valve (probably). IF it is, $300-500 for shop to replace, seems a PIA to replace if I’m doing it (I have garage but not a shop). It’s NOT throwing any error codes and as far as I know, everything is working. Just the noise.

    So, based on the above, I think I’ll just forget it until it’s an issue. Unless someone’s got some feedback that makes me go..OH MY!!
     
    #9 les.warden, Apr 17, 2019
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  10. bisco

    bisco cookie crumbler

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    pretty sure it's not a problem unless you need heat
     
    #10 bisco, Apr 17, 2019
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  11. John321

    John321 Senior Member

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    In our 08 Prius when the 3-way valve failed the vehicle sent a code that they valve wasn't in the position it thought it should be. This occurs mainly when the vehicle it turned off or turned on and the heat storage canister fluid is being transferred.

    Another possibility is that your brake actuator is beginning to fail. The actuator assy. is located on the firewall on the drivers side of the cabin. This assy. will begin making noises that you can almost set your watch by while you are driving the car or the car is in ready. The actuator is struggling to maintain correct brake pressure and is continually operating trying to maintain pressure. A good actuator will have to work only infrequently to maintain pressure.
    As the actuator continues to get worse it will eventually set codes when it can no longer maintain pressure.

    I have experience failure of both these item on my 08 and went ahead and replaced them myself. There are some good threads here on the forum detailing how to replace each of these items.
     
    #11 John321, Apr 17, 2019
    Last edited: Apr 17, 2019
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  12. JC91006

    JC91006 Senior Member

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    This noise will be gone after you replace the 3 way valve. A dealer will replace it if you are under California carb warranty, under 15 years and 150k miles. But I believe the dealer will still need the car to throw code p1121 before they'll address it
     
    #12 JC91006, Apr 17, 2019
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  13. caravan2429

    caravan2429 Junior Member

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    3-way coolant valve. Do you have P1121 code and Engine Check light on? I'm facing the same issue. I just ordered "Dorman 3-way valve", which is half of price of OEM one. However, there are bad reviews on any site, so I'm worrying how long it will last. It is on the way shipping......
     
    #13 caravan2429, Apr 19, 2019
  14. JC91006

    JC91006 Senior Member

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    If you're going to save money by DIY, why go cheap? It's a bit of a tight fit to get this out.

    @jerrymildred has some ptsd from it
     
    #14 JC91006, Apr 19, 2019
  15. les.warden

    les.warden Junior Member

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    No code, no check engine light. That’s why I’m saying forget it for now. Let us know how your replacement goes. I may do at a later time.
     
    #15 les.warden, Apr 19, 2019
  16. JC91006

    JC91006 Senior Member

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    There would be a code if check engine is on
     
    #16 JC91006, Apr 19, 2019
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  17. caravan2429

    caravan2429 Junior Member

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    Sometimes the engine check light comes on and off in intervals, I have no light on now but still sometimes randomly hear the sound from the coolant valve. You may check your code later. It is about time to replace it because of instability.
     
    #17 caravan2429, Apr 19, 2019
  18. caravan2429

    caravan2429 Junior Member

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    I would pay a mechanic to install it, though I know there are DIY videos on Youtube. It may be trickier to DIY with my little experience. I just want to try some cheap parts if it works well.
     
    #18 caravan2429, Apr 19, 2019
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