Water pump replacement need advice on mechanic estimate

Discussion in 'Gen 3 Prius Technical Discussion' started by irfanlai, Aug 21, 2025 at 11:19 PM.

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  1. irfanlai

    irfanlai Junior Member

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    I have 2012 Toyota Prius 4 with 150k miles. I am getting following check engine light P261B

    This is my old post for the same issue Radiator dashboard lights ON...what does it mean | PriusChat

    Radiator light is getting On, Coolant was getting empty after driving at a speed of 70 mph. Once car went into limp mode.

    Mechanic diagnostic findings:
    Under Vehicle:
    Oil leak on rear of motor possible head gasket leak or timing chain tensioner leak start at top of engine and work down valve cover gasket starting to seep oil on rear of motor. recommend replacing valve cover gasket pressure washing engine and readvising.

    Tested for power and ground at water pump connector found good voltage and properly grounded. Tested signal wires for pulses going in and out of the water pump found that the return had more pulses than needed causing codes in ECM. Watching live data when pump was commanded to 3,000 rpm actual calculated rpm was 6,000+. recommend replacing water pump and retesting. low coolant level most likely do to vehicle over heating and spraying out of coolant reservoir pressure tested system and found no obvious leaks. faulty water pump can lead to over heating. Recommend replacing thermostat housing due to overheating issues.

    Attached is the estimated cost report. I am confused with the repair cost. Do you guys think this is acceptable?
    Do you think its worth replacing it?
     

    Attached Files:

    #1 irfanlai, Aug 21, 2025 at 11:19 PM
  2. Grit

    Grit Senior Member

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    Damn 2 posts for 1 issue?! Our society is craving for attention!
     
    #2 Grit, Aug 22, 2025 at 12:10 AM
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  3. irfanlai

    irfanlai Junior Member

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    I wanted to make sure mechanic diagnostic can be focused on this post hence created a new one.
     
    #3 irfanlai, Aug 22, 2025 at 12:27 AM
  4. Tombukt2

    Tombukt2 Senior Member

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    The monkeys from the Amoco commercial can do this job without consequence oh y'all May remember AAmco
     
    #4 Tombukt2, Aug 22, 2025 at 10:31 AM
  5. Mendel Leisk

    Mendel Leisk MMX GEN III

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    With 150k miles, I’d replace water pump, and thermostat, regardless.

    Regarding your mechanic’s attributing coolant loss to “spraying out of coolant reservoir”: is there any evidence of this? There’d be a mess I think. Citing the 150k miles again, it’s more likely to be head gasket failure, leaking coolant into combustion chamber(s).

    EGR system ever been cleaned?

    I concur with @Grit btw: always frustrating to see double post, on what’s essentially the same saga.
     
    #5 Mendel Leisk, Aug 22, 2025 at 11:22 AM
  6. BiomedO1

    BiomedO1 Senior Member

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    $73.19 for that bueatiful estimate...... IMHO; find a small mom & pop shop without all those fancy expensive toys & also start looking for another car. Over the past month or two; there's a high likelihood that you've done irreparable damage to that engine by the constant overheating it. Water pump and thermostat are going to be the least of your worries - a band-aid; IMHO

    Good Luck....
     
    #6 BiomedO1, Aug 22, 2025 at 12:18 PM
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  7. PriusCamper

    PriusCamper Senior Member

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    This pump is electric and is as easy as an oil change to replace... There's plenty of videos on how to do it on Youtube and you only have to drain coolant down a small amount. If you or a friend or family member has basic car maintenance skill, there's no reason to spend alot of money on this job.
     
    #7 PriusCamper, Aug 22, 2025 at 1:30 PM
  8. irfanlai

    irfanlai Junior Member

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    What is Thermostat housing? Just thermostat or housing is different?
     
    #8 irfanlai, Aug 22, 2025 at 1:38 PM
  9. BiomedO1

    BiomedO1 Senior Member

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    One piece unit - old American cars are two separate units.
     
    #9 BiomedO1, Aug 22, 2025 at 1:58 PM
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