Heater issue! No hot air. Read many forums. Heater core hose not hot!

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Fliebly, Feb 18, 2020.

  1. pasadena_commut

    Joined:
    May 2, 2019
    154
    44
    0
    Location:
    Southern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    There isn't normally anything that fits that description in a coolant loop. The closest would be the rubber in the hoses. If one were failing badly enough to slough off that many pieces it should feel soft at that place (less rubber) and you might be able to see the damage inside from one of the ends with a flashlight. That said, I have never heard of one doing this. Blowing up or splitting, sure, but coming apart inside? Also, if chunks of rubber were coming off of the inside of a hose why would it develop voids which were not in the original rubber? Maybe if a section or all of it had overheated really badly? It's either that or somebody stuffed black foam rubber into your cooling system, which doesn't seem very likely either.
     
  2. Fliebly

    Fliebly New Member

    Joined:
    Feb 18, 2020
    22
    2
    0
    Location:
    Tx
    Vehicle:
    2007 Prius
    Model:
    II
    It is the same color as the hose. Maybe just being cycled around and around in the various pumps the pieces of foam takes on the dexterity and form of foam.
     
  3. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    9,922
    7,282
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    My brain still isn't able to go anywhere with this other than some odd undesirable chemical reaction, maybe between constituents of mixed coolants, or maybe between constituents of coolant and of the hose material.

    I may have nightmares for a while about the dexterity of this foam.
     
  4. pasadena_commut

    Joined:
    May 2, 2019
    154
    44
    0
    Location:
    Southern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    If the crud came from a hose the first order of business would be to be sure said hose is no longer in the cooling loop. The link in #23 is interesting since it suggests some combinations of coolant and hose chemistries can produce problems like this. I don't know about you folks, but one black rubber hose looks very much like another to me, and surely many hoses have been replaced on Priuses with whatever the local auto shop had on hand without this sort of disintegration taking place. So at the very least give the current hoses a very thorough inspection, and if in doubt, replace them.
     
  5. Fliebly

    Fliebly New Member

    Joined:
    Feb 18, 2020
    22
    2
    0
    Location:
    Tx
    Vehicle:
    2007 Prius
    Model:
    II
    Just wanted to thank y’all for the dialog. I got all the air out of the system today and the heater returned to functioning. Conclusion, there was blockage in the heater coolant loop of an unknown foamy substance in the auxiliary water pump behind the inverter for future reference. After I found the blockage, I did a complete coolant flush. Used a water flush on the loops to check for blockage. Changed the part, filled the system, and purged all air out of the system.
     
    #24 Fliebly, Mar 6, 2020
    Last edited: Mar 6, 2020
    valde3 and Raytheeagle like this.
  6. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    40,355
    28,910
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    It was from the engine coolant circuit? I'd assume so, if it's affecting cabin heat.

    If you've got any of that stuff, see if it'll dissolve in a 50/50 mix of white vinegar and distilled water. That formula is recommended for dissolving/flushing one stop-leak product, FWIW.

    Maybe you're out of the woods now, but if you have issues down the road, something to try.
     
  7. LDT08

    LDT08 Junior Member

    Joined:
    Dec 18, 2018
    13
    4
    0
    Location:
    Florida
    Vehicle:
    2008 Prius
    Model:
    Two
Loading...