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

heating blows cold air

Discussion in 'Gen 3 Prius Main Forum' started by memento84, Oct 28, 2017.

Page 1 of 2
  1. memento84

    memento84 Junior Member

    Joined:
    Jun 8, 2016
    28
    7
    0
    Location:
    Cleveland
    Vehicle:
    2007 Prius
    Model:
    N/A
    just noticed couple days ago, became apparent at 37F. air that comes out is cold, maybe little warmer than ambient. blower works ok. any ideas ? relay/fuse ???
     
    #1 memento84, Oct 28, 2017
  2. BZzap!

    BZzap! Senior Member

    Joined:
    Jun 13, 2012
    1,607
    877
    0
    Vehicle:
    2012 Prius
    Model:
    Two
    Check your temperature setting ?
     
    #2 BZzap!, Oct 28, 2017
  3. memento84

    memento84 Junior Member

    Joined:
    Jun 8, 2016
    28
    7
    0
    Location:
    Cleveland
    Vehicle:
    2007 Prius
    Model:
    N/A
    i have set it at HI , but also tried all settings 70-85F. so that is not it. any other ideas ?
     
    #3 memento84, Oct 28, 2017
  4. David Beale

    David Beale Senior Member

    Joined:
    Jul 24, 2006
    5,963
    1,985
    0
    Location:
    Edmonton Alberta
    Vehicle:
    2012 Prius
    Was the coolant changed recently? There may be an air bubble in the system. It's also possible the electric coolant pump has failed.
    I see you have a 2007 Prius, which is a GII. Unless you haven't updated your info. ;)
     
    #4 David Beale, Oct 28, 2017
    Raytheeagle likes this.
  5. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,166
    50,060
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    thermostat, blocked heater core.
     
    #5 bisco, Oct 28, 2017
  6. memento84

    memento84 Junior Member

    Joined:
    Jun 8, 2016
    28
    7
    0
    Location:
    Cleveland
    Vehicle:
    2007 Prius
    Model:
    N/A
    changed water pump couple months back. heating was fine.
    blocked heater core - how to troubleshoot that ?
     
    #6 memento84, Oct 28, 2017
  7. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,166
    50,060
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    waterpump is not the thermostat, is it? maybe need to read the coolant temp. not sure how to check the heater core.
     
    #7 bisco, Oct 28, 2017
    Raytheeagle likes this.
  8. memento84

    memento84 Junior Member

    Joined:
    Jun 8, 2016
    28
    7
    0
    Location:
    Cleveland
    Vehicle:
    2007 Prius
    Model:
    N/A
    1 clue - I could hear some gurgling noise, seemed like it was somewhere under the dash, but no leak ever (thought that was coming from engine compartment) - would that mean some obstruction in the heater core ??????
     
    #8 memento84, Oct 28, 2017
  9. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,166
    50,060
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    gurgling might mean you need to bleed the system, but i'm not positive.
     
    #9 bisco, Oct 28, 2017
    Marcilla Smith likes this.
  10. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,257
    15,491
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    If a Gen3: Have you checked the hoses and coolant in the overflow and they are warm?

    If a Gen2: have you checked the level in the radiator and are the hoses warm?
     
    #10 Raytheeagle, Oct 28, 2017
  11. memento84

    memento84 Junior Member

    Joined:
    Jun 8, 2016
    28
    7
    0
    Location:
    Cleveland
    Vehicle:
    2007 Prius
    Model:
    N/A
    I will try to locate hoses for the heater core - it seems like a common problem (kind of), will try to blow it thru, opposite direction that it normally flows.
     
    #11 memento84, Oct 28, 2017
  12. memento84

    memento84 Junior Member

    Joined:
    Jun 8, 2016
    28
    7
    0
    Location:
    Cleveland
    Vehicle:
    2007 Prius
    Model:
    N/A
    it is 3rd Gen.
    Coolant in overflow should be warm right ? the return one (upper) should be warm/hot right ?
     
    #12 memento84, Oct 28, 2017
    Raytheeagle likes this.
  13. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,257
    15,491
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    The overflow and hoses should be hot if the full warm up cycle has been completed;).
     
    #13 Raytheeagle, Oct 28, 2017
  14. memento84

    memento84 Junior Member

    Joined:
    Jun 8, 2016
    28
    7
    0
    Location:
    Cleveland
    Vehicle:
    2007 Prius
    Model:
    N/A
    I checked that when replaced the water pump, and they were ok - will do it again! how hard is it to locate heater core hoses ?
     
    #14 memento84, Oct 28, 2017
    Raytheeagle likes this.
  15. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,257
    15,491
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    Water pump was replaced? How many miles? What was the cause of the previous pump failure?

    The easiest hose to check is the one off of the overflow reservoir ;).

    Keep us posted (y).
     
    #15 Raytheeagle, Oct 28, 2017
  16. memento84

    memento84 Junior Member

    Joined:
    Jun 8, 2016
    28
    7
    0
    Location:
    Cleveland
    Vehicle:
    2007 Prius
    Model:
    N/A
    186k, pump died. so the return to overflow is heater core "out" ? will update asap
     
    #16 memento84, Oct 28, 2017
  17. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,257
    15,491
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    The electric water pump died:(?

    Did you hange it yourself ? Get it back if not or ask what the failure was from?

    Here are 2 pics of water lines to check:

    Off of the overflow reservoir 57451CF1-B5CF-4947-A0FE-26324C588AED.jpeg

    On of the egr cooler 50759C31-DA84-410C-9A83-5F3794DDB7E2.jpeg

    Keep us posted(y).
     
    #17 Raytheeagle, Oct 28, 2017
    bisco likes this.
  18. BZzap!

    BZzap! Senior Member

    Joined:
    Jun 13, 2012
    1,607
    877
    0
    Vehicle:
    2012 Prius
    Model:
    Two
    Does the blower work?
    After all that’s said an done, it sorta points to a bad Blend door actuator. Almost all modern cars have the coolant circulatiing through the heater core constantly. The heat is controlled by opening and closing these doors with a motor that is controlled from the HVAC module. It’s all electronic. It’s also possible that the control head is malfunctioning.
     
    #18 BZzap!, Oct 28, 2017
  19. BZzap!

    BZzap! Senior Member

    Joined:
    Jun 13, 2012
    1,607
    877
    0
    Vehicle:
    2012 Prius
    Model:
    Two
    BTW the coolant control valve is electronically controlled... no vacuum involved. This might be the source of your problem. You might want to turn the heater on and try gently tapping the control valve then check to see if you get heat. Another scenario is no signal from the controls. Fuse, maybe? Bad control module? Bad valve?
     
    #19 BZzap!, Oct 29, 2017
  20. David Beale

    David Beale Senior Member

    Joined:
    Jul 24, 2006
    5,963
    1,985
    0
    Location:
    Edmonton Alberta
    Vehicle:
    2012 Prius
    I'm still thinking he's got an air bubble in the heater lines, after replacing the water pump. Simple things first! ;)
     
    #20 David Beale, Oct 29, 2017
    Raytheeagle likes this.
(You must log in or sign up to post here.)
Page 1 of 2