Heater Question

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by jcoasternut, Nov 27, 2019.

  1. jcoasternut

    jcoasternut Junior Member

    Joined:
    Jun 12, 2008
    5
    0
    0
    Location:
    Indiana
    Vehicle:
    2008 Prius
    My 2008 Prius heater has always baked me out of the car in 10 minutes if set on high. Now it still heats, but does not bring the temperature up like before. After 15-20 minutes, although the car is warm, it is not hot where I need to turn it off or down like I have had to previously. This started this week. Otherwise, no issues with car. Cabin air filter was replaced last week, but I have checked it and it is fine. At present the situation is ok as there is heat and it is not extremely cold yet, but is it getting ready to totally fail?
    Thanks for any input !!!
     
  2. john1701a

    john1701a Prius Guru

    Joined:
    Jan 6, 2004
    11,835
    4,562
    57
    Location:
    Minnesota
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Your anti-freeze may be low (so it isn't circulating well) or the thermostat is stuck (so it is constantly circulating). Either one will prevent the heater core from pumping out lots of heat. In both cases, an aftermarket device is the easiest way to confirm a coolant related problem. ($10 on Amazon for a reader and a free app download.) The temperature will help tell us what's going on.
     
    Mendel Leisk likes this.
  3. jcoasternut

    jcoasternut Junior Member

    Joined:
    Jun 12, 2008
    5
    0
    0
    Location:
    Indiana
    Vehicle:
    2008 Prius
    Thanks, not sure what type of reader you are referring to, but I checked the coolant and is is full. It is protected to 40 below. Took a long trip yesterday and had no issues with heater except is not as hot as previously. Has about 140,000 miles currently.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    39,294
    27,961
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Could be the coolant thermostat going. It'd be nice if the Prius had a coolant temp gauge, most any econobox car used to have it. You could monitor engine coolant temps with Scangauge or maybe other? If you have a thermostat failing in a manner that it's opening too soon, and/or not sealing properly when closed, you'll tend to be running too cold, especially with freeway driving.
     

    Attached Files:

Loading...