Water pump valve is slow

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Emma10.10, Jul 22, 2025 at 6:52 PM.

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  1. Emma10.10

    Emma10.10 New Member

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    After 2 months of troubleshooting and repair$, mostly at the dealership, I at last, drove my car home. At about 100 miles; the check engine light came on. The dealership technician said it was the water pump valve working slowly. To replace the valve: $500.

    I’m thinking it’s been sitting for so long, maybe it will start working again after being driven more regularly. The light’s been off for another 100 miles. If I don’t replace the valve, am I gambling, courting more expensive repairs?
     
    #1 Emma10.10, Jul 22, 2025 at 6:52 PM
  2. PriusCamper

    PriusCamper Senior Member

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    First step is to get away from the Toyota Stealership with a car that old. They are warranty specialists focused on maximizing cost of repairs to newer cars to increase the financial leverage with the manufacture. They play the same game with out-of-warranty customers too. You're often paying more than double at a stealership for parts and labor and compared to a reputable mechanic.

    Based on you description problem is likely P1121, which is a part you can buy aftermarket for as cheap as $40 and it takes about 1.5 hours to swap out it out. If you live near me that'd mean I'd charge you about $100...

    Alternatively, if you or a friend or family member has basic automotive skills we can walk you through this repair. What's more, this specific problem will only lower MPG slightly, it won't damage or prevent you from driving the car.
     
    #2 PriusCamper, Jul 23, 2025 at 3:18 AM
    Last edited: Jul 23, 2025 at 3:38 AM
  3. PriusCamper

    PriusCamper Senior Member

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    #3 PriusCamper, Jul 23, 2025 at 3:24 AM
  4. Emma10.10

    Emma10.10 New Member

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    #4 Emma10.10, Jul 23, 2025 at 1:11 PM
  5. Emma10.10

    Emma10.10 New Member

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    Thank you for the warning about stealership! I’ve only been ripped off by mechanics a few times. The first time was in 1976 when I was 26. The experience drove me to take a series of car maintenance and repair classes for women. After that, I very seldom went to a mechanic under a tree or a dealership!

    I am now a new resident of small town, not far from the Motor City. I’m fixing up a very old house, and had this Prius since 2018. It almost never had a problem, so almost never opened the hood! The hybrid battery, a wheel bearing, muffler and other things caused me to trust a good mechanic who gave up on my car. They sent me to the dealer. I had no other options.

    The dealer did finally fix everything. im getting 47mpg, no idiot lights and so, with your encouragement and my educated guess, that even if the water pump valve might be slow, I’m not endangering the vehicle by ignoring dealer recommendation. I love my Prius. Thanks again!
     
    #5 Emma10.10, Jul 23, 2025 at 1:40 PM
    PriusCamper and bisco like this.
  6. bisco

    bisco cookie crumbler

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    check engine is not necessarily the water pump, so if it comes on again, have the trouble codes read.
    and check your oil level asap
     
    #6 bisco, Jul 23, 2025 at 3:46 PM
  7. PriusCamper

    PriusCamper Senior Member

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    Get the exact error code from the stealership... I've know people to drive for several years with a P1121 with no harm caused. Specifically this pump manages hot coolant storage into the thermos so when you start a cold engine the next day that hot coolant boost your MPG by helping the engine heat up faster.

    Moving forward, because you've invested in getting an education on car repair I encourage you to lean on Priuschat as much as possible in the future because we can walk you thru any repair, as well as help you find someone capable near you to do repairs.
     
    #7 PriusCamper, Jul 23, 2025 at 4:56 PM
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