1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Water Pump Question

Discussion in 'Gen 3 Prius Main Forum' started by MelonPrius, Jul 3, 2024.

  1. MelonPrius

    MelonPrius Senior Member

    Joined:
    Apr 13, 2017
    821
    509
    0
    Location:
    Las Vegas
    Vehicle:
    2014 Prius
    Model:
    Three
    I know this topic has been covered before, but I'd still like to get some feedback.

    At 120k miles, I'm going to replace my water pump out of precaution. There are no obvious signs of needing replacement. But I'll be taking a few trips this summer driving through long stretches of desert.

    1. Can I just replace the engine water pump, or is it common practice to replace both water pumps?

    2. While the mechanic is doing the work, is there anything else that needs to be done? I read in another thread that the thermostat should be replaced but I'm not sure how many miles they last.

    3. Does it matter which brand of water pump to use? What is recommended.

    I had my EGR cleaned at 90k miles. I'll need a new hybrid battery within a year (38% life left as per Dr. Prius) and don't know if I'll get a new battery or sell the Prius. So, I'm not looking to spend too much money just in case I end up selling the car soon.
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,908
    49,484
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i don't think we've seen enough water pump failures at your age and miles to bother
     
  3. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    11,104
    4,516
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    With the quality issues with pumps these days you may be trading in your original water pump that's more reliable for another pump that less reliable.

    And because these water pumps are easy to replace if they fail... Just buy a spare pump and watch a you tube video on how to replace it and wait for an error code telling you the pump is bad before replacing it.
     
  4. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,482
    8,400
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    If you're thinking of possibly selling the Prius, I wouldn't bother changing out the pump. Mine had an error code at 214k miles. It was a over rotation code, it didn't actually fail. I went on Amazon and bought a new water pump rotor to replace the old unit. Yours at 120k miles should have plenty of life left (at least another 50k before you need to think about replacing it)

    I didn't want to spend a lot on this engine as it's nearing the dreaded "need head gasket" mileage. So I refurbished the water pump with a new rotor and it should last until the engine needs a head gasket.
     
  5. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,009
    15,610
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    There has to be an explanation for the overrevving though. Often it happens when a part of the pump impeller has broken off so that it can spin faster because it's moving less water.

    Another cause can be coolant so low it is spinning in air, which is also not ok.

    It seems like Toyota added the P148F overrevving code in 2011; a 2010's water pump can have its impeller break like that and you don't get a code, because its ECM was never programmed to think spinning too fast could be a problem.
     
    PriusCamper likes this.
  6. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,482
    8,400
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    I did check the impeller fins and they were not broken. The thing I did notice was the thin plastic magnetic housing on the rotor was broken and somehow that made the impeller spin at an irregular speed.

    The error that came up was simply the temperature symbol on my dash. It came up for about 10 seconds and it went off. That's the only indicator of the actual error, the car was driving normally. P148F came up and the rotation was about 800rpm faster than normal

    My coolant was slightly low, maybe had to add 8oz a few months ago. I was worried that was a sign of head gasket failure but after adding the 8oz, the coolant has been stable.
     
    #6 JC91006, Jul 4, 2024
    Last edited: Jul 4, 2024
  7. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    11,104
    4,516
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    Good example of growing pains for new technology... It's probably better than the older water pump tech, but at first it doesn't seem like it.
     
  8. MelonPrius

    MelonPrius Senior Member

    Joined:
    Apr 13, 2017
    821
    509
    0
    Location:
    Las Vegas
    Vehicle:
    2014 Prius
    Model:
    Three
    Thanks for the input, everyone. Based on the feedback, I'll hold off on the water pump for now. I had a '96 Jaguar and I was on my 3rd water pump before hitting 110k miles. I love the Toyota dependability on certain parts.


    Thanks for the response. Just out of curiosity, what is your "need head gasket" mileage? (assuming it applies to my turd gen)
     
  9. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,482
    8,400
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    The "need head gasket" mileage is after 160k miles on a Turd gen car.
     
    Brian1954 likes this.
  10. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    55,562
    38,724
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Just my opinion: with thorough/complete EGR cleaning every 50k miles, the answer may be never.
     
  11. Ryan Will

    Ryan Will Member

    Joined:
    Jun 18, 2022
    68
    43
    0
    Location:
    Southern California
    Vehicle:
    2015 Prius
    Model:
    Three
    Just throwing in something a dealership mechanic told me a few years back - He actually did say to keep on top of the EGR system even if Toyota officially never really says to clean/replace it. But he also said that the water pumps are known to go without any warning around the 100,000 mile mark (give or take of course). At this dealer they worked on a lot of taxi/Uber/Lyft Priuses and that was almost always the issue they found. From that, I just replace mine around every 100,000 miles. I'm almost to 180,000 miles so will likely be replacing it soon to be proactive.
     
    bisco and Brian1954 like this.
  12. VitoinTn

    VitoinTn New Member

    Joined:
    Jul 5, 2024
    2
    1
    0
    Location:
    Clarksville, TN
    Vehicle:
    2013 Prius
    Model:
    Four Touring
    My daughter's 2013 with 169k mi started running a CHECK ENGINE light and intermittent TEMP light last week. Had low coolant in reservoir and had to show her WHERE it was. Topped it off.

    Now this week, same things...topped it off and hooked up code scanner;
    P148F Coolant Pump Over Revolutions
    P0117 Coolant Temp Circuit Low Input
    P261B Coolant Pump B Control Malfunction

    After the top off and a 10mi drive, the coolant level was back down to half in reservoir, but TEMP light went off after turning AC off. Haven't noticed any leakage underneath or in driveway with reservoir cap on or off.

    So am I looking at having to replace the Engine Coolant Pump?
     
  13. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    55,562
    38,724
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    The coolant will be disappearing somewhere. EGR and intake manifold ever cleaned? Any rough start-up after it’s sat overnight?
     
  14. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,009
    15,610
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    With those codes, definitely fix the pump problem.

    "Fix the pump problem" won't always mean the pump itself is at fault; sometimes you'll want to rule out a wiring issue. But in this case, both P148F (revs too high) and P261B (revs too low) suggest there is power to the pump and tachometer feedback from it and the problem is pretty darned likely to be the pump itself. Likely enough I'd probably go ahead and change it without much other troubleshooting first.

    The P0117 is scary. It means the temperature sensor resistance as seen by the ECM was so low the ECM thought it might be a bogus reading. The temperature sensor is a negative-temperature-coefficient thermistor (resistance goes down as temperature goes up), so bogus low input meant the temperature at the engine got so hot the ECM doubted the reading.

    You don't want that to keep happening.
     
    Brian1954 and VitoinTn like this.
  15. VitoinTn

    VitoinTn New Member

    Joined:
    Jul 5, 2024
    2
    1
    0
    Location:
    Clarksville, TN
    Vehicle:
    2013 Prius
    Model:
    Four Touring
    No drivability problem or start up problems. Haven't 'cleaned' EGR or intake manifold.
     
    Mendel Leisk likes this.
  16. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    55,562
    38,724
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
  17. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,482
    8,400
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
  18. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    55,562
    38,724
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Even if I type in “water pump”, or “water pump assembly”, I get at least 22 pages, and the water pump ain’t on page one, it’s wandered off into everything but water pump. Toyota USA did a job on that parts site.

    Have a direct link?
     
  19. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,482
    8,400
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    I just tried that search function for the site, it's absolutely awful. This might have to do with the cyberattack episode they had 2 weeks ago. Can't seem to find the right part with the search function.

    This is the part that's needed

    Electric Water Pump Assembly

    Part Number: 161A0-29015 - It's $240.59 before the 20% discount and free shipping
     
    Mendel Leisk likes this.
  20. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    55,562
    38,724
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    $193.47 USD all-in. Amayama’s all-in price, converted to USD, at least at my locale, is ~$126. That’s with shipping, and with about 1/2 doz small purchases, never anything more, say tax, duty.

    It’s the Aisin WPT-190, but I believe the same. They’ve never had anything bogus in my experience.