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Coolant Pump 16290-21010/1 maybe needs replaced or is it air pockets?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by thb1000, Oct 17, 2023.

  1. thb1000

    thb1000 New Member

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    Part 1 of my Q is, which part does it sound is making the noise? I think it is the CHRS pump, part number 16290-21010/1

    Then the 2nd Q is, does it seem like an air bubble problem? or do I just need to replace that pump?

    I think the video probably explains most of my current problem but from the top here goes:

    It sounds like I have a problem with one of my pumps. When I turn the 05 prius with 228k miles on, the pump in question runs for a bit and usually shuts off, so now after further research I assume it is the Coolant Heat Recovery System pump. For I guess about a year I've heard it come on at random times while driving and sometimes stay on for a bit and now it seems to have gotten worse, and today it just didn't want to shut off practically at all during a couple hours of use. During the past year I've done many DIY repairs; replaced the brake actuator, the inverter, the inverter coolant pump, serpentine belt, front brake pads and rotors. Again the noisy pump predates all my DIY repairs; as a side note, at first I thought it was the inverter coolant pump making this noise so I changed it. No error codes or dash lights but a troubling sound. Somehow I had it in my head before today that if it wasn't the inverter coolant pump part G9020-47031, then I thought it was the Aux Engine Pump part 87200-47030 but again now I am thinking it is CHRS pump part 16290-21011. I guess there's only one other coolant pump and that is on the other side away from the noise.

    I've done the bleeding a few times now on both coolant loops, but the last few attempts have been the engine coolant loop. When I thought it was the pump to the heater core making the noise I was really focused on the 2nd part of the bleeding process where you have the car in inspection mode and the heat on but now it seems like this noisy pump of mine is addressed more during the first part of the bleeding when I jump the relay with my multimeter. I get a reading anywhere from 3.88 to 3.99 on my multimeter when the pump is running for the 20 seconds or so at a time.

    My process on the bleeding is,
    the car is off but batteries still connected,
    I connect the tubing to the bleeder valve on the radiator
    I open the bleeder valve a few turns
    I pop the relay off and activate it with the multimeter in 20 seconds spurts
    I get the 3.9 or so reading and the coolant does come out into the tube, not too fast but still I see it and eventually it flows a bit into the overflow, and there aren't any bubbles in the tube so I figure I'm done with that part.
    Then I put the car into inspection mode get the heater going full blast for 20 minutes, flooring the gas for a few minutes during that time. I check the bleeder tube it looks like solid coolant no bubbles, not moving too fast in the tube still but flowing without bubbles. So then I'm done but like today I did all that it started fine the pump barely made a noise at first but after I drove a few minutes that is when I heard it and pulled over and took that video.
    Any help would be great, thanks!
     
  2. Tombukt2

    Tombukt2 Senior Member

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    It won't let the video play at the moment I don't know all those pumps by heart. The coolant heat recovery pump that's the one in the fender well next to the coolant heat recovery tank or whatever.? And then there's another pump in between the brake actuator and the strokes emulator or whatever they call it looks like a little spa pump looks exactly like the coolant heat recovery pump except the coolant heat recovery pump is 12 volt and the one in between the two brake parts that has something else to do with the heat it looks like is 14.1 volts. So I'm not sure which pump you're exactly talking about I can ever hear my coolant heat recovery pump running the one down and below the headlight and I don't know that I've ever heard the one between the brake parts come on but everything on the car works so I've just left it. Usually once you start to hear pumps other than the brake pump. Something might be up like a worn out impeller or mag drive not working right something and then you might change it Air will cause the same thing so you want to make sure you're milking hoses and got caps off and all that stuff and see if the sound changes. If it does maybe continue trying to get the air out so on and so forth and it'll get back to normal. These pumps seem to hold up for a long time except the inverter coolant pump and apparently nobody can make them correctly except the one company that does it for Toyota even if you buy some of their seconds they seem to fail immediately 2 weeks a month whatever.
     
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  3. Primetime Paul

    Primetime Paul Junior Member

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    I hear your inverter pump sounds good, that noise sounds like an actuator wigging out, do you have any trouble codes?

    Pixel 7 Pro ?
     
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  4. dolj

    dolj Senior Member

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    That is the infamous sound of the coolant flow control valve seeking but not finding. It is a common enough problem. Look up some old posts on the subject. If you were inclined to read the codes you would probably see a P1121.

    Reading the codes saves you the aggravation of off-base assumptions.
     
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  5. mr_guy_mann

    mr_guy_mann Senior Member

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    +1 for a bad coolant control (3-way) valve.

    I might expect that you should find a P1121 in the ECM, but car doesn't really care about my opinions.

    The valve is bad - specifically the position sensor inside it. Replace the valve with a Toyota part from a reputable source and move on with life.

    Posted via the PriusChat mobile app.
     
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  6. thb1000

    thb1000 New Member

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    I made sure I did a code scan for this, I have an Autel smartphone scanner that can do a prius brake bleed, and there were no codes except for the immobilizer code I ignore.

    It makes sense to me now that the sound is a valve malfunctioning not a pump, so I plan on getting the $105 valve from toyota dealer, part 16670-21010.

    Seems like I am safe to drive the car since for now at least it seems like just an ugly noise
     
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