Water pump, prevenative or wait for codes?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Hybrid_Motorsports, Nov 25, 2024.

  1. Hybrid_Motorsports

    Hybrid_Motorsports New Member

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    I was wondering how many change their water pump as a preventative. I'm seeing mixed opinions where some say to change it every 100k, others say it will go 200k. Mine is original with 145k miles. I always monitor my engine temps with a Scangauge and on the highway, they always seem to go up which I assume is normal. I have yet to see more than 199F and it seems to be pretty steady at 195 every time I am on the highway.

    I have a new Aisin pump and thermostat sitting but I'm curious how many of you had a water pump fail and if it is a catastrophic failure or if they just slowly get weaker. I'm always cautious and do preventative maintenance which now I kind of regret not putting a water pump when I did a full intake and EGR clean at 130k along with fresh coolant in the engine and inverter.
     
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  2. PriusCamper

    PriusCamper Senior Member

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    They're so easy to change... Having one at the ready if it fails is wise... Replacing it before it fails is just a waste of time and money. The exception being if you bought a used Gen3 with 200K miles and you were fixing it up as the new owner.
     
  3. Hybrid_Motorsports

    Hybrid_Motorsports New Member

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    Yes the pump looks very easy. The thermostat however looks annoying to get to when it was so simple with the intake manifold off. I might just remove it again because that take 10-15min instead of struggling to feel hidden thermostat bolts.
     
  4. Merkey

    Merkey Active Member

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    I had a similar problem at 165k miles. Scangauge showed a couple of over 200F events but didn't last long. Car was diveable for awhile until it eventually died on the xway. After cooling down I was able to get it to the dealer where they diagnosed a bad water pump. About $500 for the pump and $600 for labor. It seems to slowly deteriorate, but then gets much worse. probably
    not a bad idea to be premptive considering what can happen.
     
  5. PriusCamper

    PriusCamper Senior Member

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    Wow... That's more than Lawyers charge... It's why we call them Toyota Stealerships... In truth, the pump costs less than $100 online and it barely takes a half hour. Sure wish there was jail time for Toyota mechanics who think they can get away with charging a thousand dollars an hour because they know they can get away with it. If you don't believe me, check out Youtube videos on how easy it is to replace this pump.
     
  6. Tombukt2

    Tombukt2 Senior Member

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    On this model that 200K is real close to end of life for that system . Is engineered so. Don't try and reinvent what the mfgrs worked so hard to implement. Silly.
     
  7. BiomedO1

    BiomedO1 Senior Member

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    Kudos for monitoring your ECT! Those pumps usually get weaker. If you don't change your coolant or mix junk in there, that can stop the impeller from turning - your catastrophic failure.
    Just keep monitoring your ECT, especially during hot summer months. If it can't keep the engine cool (below 230F), I'd change it the following weekend along with coolant.

    Hope this helps....

    PS; also check cooling fan operations - when they die, they tend to go unnoticed. I've bought and flipped a few cars like that. The repair shop those poor people was taking their car to couldn't figure-out how to fix the intermittent overheating issue.:(:eek:o_O:sleep:
     
    #7 BiomedO1, Nov 26, 2024
    Last edited: Nov 26, 2024
  8. Mendel Leisk

    Mendel Leisk Witness Leader

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    Ouch:

    Buy AISIN WPT190 Pump, Water. Prices, fast shipping, photos, weight - Amayama

    For me it's showing $136 CDN, and "?" for shipping. From past experience with them shipping probably $35~40 CDN. Also based on past purchases around that amount: NO extras, say sales tax, import duty, whatever.

    @Hybrid_Motorsports I'd do replacement next time you're doing coolant, presumably at 150K miles, per the US schedule.
     
  9. ASRDogman

    ASRDogman Senior Member

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    $600 labor????? Do they charge $300 an hour?
    2 hours is the MOST it should take them to diagnois and replace.

    And $500 for the pump? Seems kinda high, even for Toyota.
    Be carefull of the autostores ones, most seem to be cheap copies.
    Some say the Aisin pumps are the same as the Toyota ones and they make them for Toyota.
    They seem to cost $2-300.
    If you are in not hurry, ordering them online and waiting for it to arrive could cost you less money.

    It would probably be safer to order online from a Toyota dealership. At least you know you get,
    or should get, a Toyota pump, just for less money.


     
  10. Merkey

    Merkey Active Member

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    I know it's always expensive at a dealer, but I didn't want to risk getting a couterfeit part. Plus it's hard to find
    independents willing to work on them around here.
     
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  11. Hybrid_Motorsports

    Hybrid_Motorsports New Member

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    Just finished replacing the water pump and thermostat and my concerns were validated. The pump had no physical damage and spun freely but my coolant temperatures on the highway are now steady at 184-186F compared to the original pump always jumping to 195-200F when driving on the highway. Still in acceptable range I'm sure but without a Scangauge, you would never know your water pump wasn't as efficient as it should. I'm curious about what coolant temperature the check engine light actually turns on but I did not want to find out personally and risk a head gasket failure. The engine has enough stress on it from all the heat cycles.
     
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  12. ASRDogman

    ASRDogman Senior Member

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    Since the impeller turned freely, (NO resistance at all? You should have felt the magnets),
    They the pump was likely okay. The thermostat probably wasn't opening at the correct range.

     
  13. Hybrid_Motorsports

    Hybrid_Motorsports New Member

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    The pump had some resistance but I compared it to the new one and it was ever so slightly stiffer but nothing drastic. It could have been a tired thermostat that wasn't opening fully, I guess il never know for sure since I changed them together.
     
  14. ASRDogman

    ASRDogman Senior Member

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    You can look at the impellor and see it the plastic over the magnet is swelled or torn.
    You have to remove the teeny tiny "O" ring that holds it on the shaft to remove it.

    It's probably a good idea to replace it with all those miles, certainly won't hurt. Unless it's a cheap
    chinese copy one.... You can find those impellers on ebay and amazon.

     
  15. Hybrid_Motorsports

    Hybrid_Motorsports New Member

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    I was thinking of getting an impeller but I just can't trust the chinese parts since the impeller itself isn't made by Aisin or Toyota. I just went with a new Aisin unit to have peace of mind.
     
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  16. BiomedO1

    BiomedO1 Senior Member

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    If no-one has answered the question, OEM temp lamp trips around 240F.
     
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  17. Hybrid_Motorsports

    Hybrid_Motorsports New Member

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    Good to know thanks
     
  18. Hybrid_Motorsports

    Hybrid_Motorsports New Member

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    Took the impeller off and it is ever so slightly misshaped. It does not spin true and you can see it wobbling around so I'm sure it wouldn't have been long before it cracked.
     

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    #18 Hybrid_Motorsports, Dec 4, 2024
    Last edited: Dec 4, 2024
  19. ASRDogman

    ASRDogman Senior Member

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    It looks fine in the photo, but they are misleading....
    Likely you found your problem... (y)

     
  20. Hybrid_Motorsports

    Hybrid_Motorsports New Member

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    Yes, it's hard to tell from the picture but I'm glad I looked into it before it truly failed. I want my cars to run as good as they can.
     
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