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

Heat Not Working in 2008 Prius

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Edwin_H, Nov 3, 2014.

  1. Edwin_H

    Edwin_H New Member

    Joined:
    Nov 3, 2014
    3
    0
    0
    Location:
    Winder, Georgia
    Vehicle:
    2008 Prius
    Model:
    N/A
    Hey everyone,

    I'm new here, but need some feedback/help. This morning I turned on my Prius, turned on the heat, and let the car warm up. When I came back five minutes later, the car was on but the engine wasn't running and the vents were only blowing out cold air despite the thermostat being set at 75° and it was 37° outside. I noticed after driving for about 20 minutes, that when I pushed on the accelerator and made the gas engine do the work, the air coming out was nice and warm. However, when I let off of the gas and let the electric motor take over, it went cold again. I recently had the dealership replace the hybrid electric water pump that was a recall repair notice. That wouldn't have anything to do with this would it?

    The Toyota dealership in my town told me after six hours of looking at my car, that I needed to have the water pump replaced along with the three way valve assembly and the thermostat. Total cost $960.

    Does this sound right? Thanks in advance!
     
    #1 Edwin_H, Nov 3, 2014
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,470
    8,383
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    What you are describing is usually associated with air being trapped in your system, probably from a slowly leaking ICE water pump. It would be a strange coincidence this happens after the hybrid electric water pump recall. This service should have no effect on the ICE engine side, which is what the dealer is proposing to fix for $960.

    I would think if you changed the water pump (which will fix the leak) and refill/change the coolant, get the air out of the system, that should fix the problem. I don't think the 3 way valve assembly would be an issue at this time and you can probably skip this service and save some money. If this was an issue, you might have gotten a warning light or DTC stating so.

    You can change the water pump yourself, it's a fairly simple DIY project. There are many write up on priuschat to show you how to do this. But if you leave it up to the dealer, it may cost around $600 to do it. If you decide to do this, you might want to change the serpentine belt at the same time. This should not incur any additional labor charge, the belt has to be removed to change the water pump. There should be only a "parts cost ($20)" associated with changing the belt at the same time.
     
    #2 JC91006, Nov 3, 2014
    Last edited: Nov 3, 2014
  3. paprius4030

    paprius4030 My first Prius

    Joined:
    Aug 12, 2004
    2,077
    295
    0
    Location:
    Ormond Beach,Fl.
    Vehicle:
    2012 Prius
    Model:
    Two
    If you have the dealer do this maybe you should look for another dealer.
     
    #3 paprius4030, Nov 3, 2014
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,199
    6,464
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    The Prius has four coolant pumps, so you should be clear regarding which pump is being suggested for replacement.

    Given your observation that the cabin heat works while the engine is running, I think it is likely that the electric pump which circulates coolant to the cabin heater core has failed.

    The inverter/transaxle coolant pump was the subject of recall and that has nothing to do with this issue.

    Is the check engine light on? If not, then I doubt that the engine coolant valve (which you call three-way valve) is the problem. I also doubt that the engine thermostat is at fault.

    The engine coolant pump bearing should be inspected for coolant seepage and that pump should be replaced if this is evident. However, that would not cause the specific symptoms you experienced, where the cabin heat works fine as long as the engine is running, then stops while the engine is off.
     
    #4 Patrick Wong, Nov 4, 2014
  5. Edwin_H

    Edwin_H New Member

    Joined:
    Nov 3, 2014
    3
    0
    0
    Location:
    Winder, Georgia
    Vehicle:
    2008 Prius
    Model:
    N/A
    Thanks for the input, guys!

    Patrick - no warning lights came on at all, so, it stands to reason that the issue is with the electric water pump.

    Upon having a 2nd mechanic look at it, he found that the regular water pump was leaking (which I had been told before by someone else was an issue that would need to be fixed) and would need replacing for sure along with a belt, too.

    So, it seems as if I need to get both the regular AND electric water pumps replaced. Seeing as I have over 180,000 miles on it, I guess it's about time I started having to replace/fix things. Naturally this all happens the month after I completely paid off the car. Funny how that works, huh?

    I'll keep this post updated as I find out what ends up being the solution. At this point, I would say the dealership's suggestion of replacing the thermostat and 3-way valve were wrong and unnecessary. Time will tell.

    Thanks again for the help!
     
    #5 Edwin_H, Nov 4, 2014
  6. Edwin_H

    Edwin_H New Member

    Joined:
    Nov 3, 2014
    3
    0
    0
    Location:
    Winder, Georgia
    Vehicle:
    2008 Prius
    Model:
    N/A
    So, I'm going to get the mechanical water pump and belt replaced and see how it's doing after that. The electric pump that Patrick mentioned, which circulates the coolant to the cabin heater core is $600 (not including labor costs)! I can live with partially working heater to save that expense.
     
    #6 Edwin_H, Nov 10, 2014
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,199
    6,464
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    #7 Patrick Wong, Nov 10, 2014
(You must log in or sign up to post here.)