Welcome to PriusChat

We'd love to have you join our community and participate in the conversation! Sign up for FREE today.

Sign Up

Radiator coolant not heating up or under pressure

Discussion in 'Gen II Prius Care, Maintenance and Troubleshooting' started by DirkG, Oct 29, 2010.

Social Buttons

  1. DirkG

    DirkG Junior Member

    Joined:
    May 22, 2009
    Messages:
    27
    Likes Received:
    0
    Location:
    Eugene, OR
    Your Vehicle Year:
    2007 Prius
    Model:
    N/A
    My 2007 has 160k miles and at just over 100k I had toyota change all the fluids. That was about 3 or 4 months ago, its a taxi. I started noticing the heat was only hot above 83, and some times not even hot at high. I thought I was out of fluid so I added to the overflow not wanting to open the cap on a hot motor. It didnt take much, but made the heat come back on above 80 degrees so I did nothing else.
    Last night I had no heat again after driving about 200 miles. The heat came back after turning it off for a few minutes, but I stopped at a gas station anyway when I got off the freeway.
    The overflow was full. It was also cold. So were the radiator hoses, but not what looked like power steering hoses next to it. Were those the inverter lines?
    I check that belt pullie was spinning when the engine was running, it was. It a new belt put on by dealer.
    The car doesnt show any signs of overheating, and is driven 300 or more miles a day in town and freeway. The motor was of course hot, but not overly so. None of the connected components were hot like I would expect if was overheating.
    This is something I really need to fix myself due to money shortages. Sounds like a thermostat or waterpump in a standard car, but what about in a Prius?
    Thanks
    David


    edit: I should add that when the radiator cap is off, the heat on, and the engine running, there is no movement in the antifreeze, which is full to the top of the neck but has no pressure.
  2. DirkG

    DirkG Junior Member

    Joined:
    May 22, 2009
    Messages:
    27
    Likes Received:
    0
    Location:
    Eugene, OR
    Your Vehicle Year:
    2007 Prius
    Model:
    N/A
    Lots of failing inverter pump threads. Maybe while I am fixing the ICE problem, I should put a new inverter pump on also.
  3. donee

    donee New Member

    Joined:
    Aug 15, 2005
    Messages:
    2,959
    Likes Received:
    188
    Location:
    Chicagoland
    Your Vehicle Year:
    2010 Prius
    Model:
    III
    Hi DirkG,

    This sounds more like a problem with the dealarship not bleeding the engine, heater core and CHS (Coolant Heat Recovery) system properly. Its especially tricky in the Gen II Prius.
  4. Hal W

    Hal W New Member

    Joined:
    Sep 26, 2010
    Messages:
    872
    Likes Received:
    52
    Location:
    Grand Forks,B.C. Canada
    Your Vehicle Year:
    2006 Prius
    Model:
    II
    Sounds like the thermostat is stuck open? H
  5. ccdisce

    ccdisce Active Member

    Joined:
    Oct 10, 2010
    Messages:
    218
    Likes Received:
    115
    Location:
    Stone Mtn GA USA
    Your Vehicle Year:
    2008 Prius
    Model:
    N/A
    Serpentine belt under tension?
    Impeller could be loose on the WP shaft.
    Colapsed hose?
  6. Joe 26

    Joe 26 Member

    Joined:
    Feb 20, 2008
    Messages:
    240
    Likes Received:
    35
    Location:
    Columbus, Ohio
    Your Vehicle Year:
    2010 Prius
    Model:
    III
    You have 3 basic possibilities

    1) Shop that changed the engine coolant did not bleed the system fully.

    2)The engine thermostat is stuck open

    3) There is some type of coolant leak or coolant loss. Since you say the reservoir is full, I wouldn't suspect this.

    First, try putting the heater on economy, full blower and max hot. Run the vehicle down the highway for 15-20 min. and see if your engine coolant reservoir gets lower. Using the max heat setting is very important.

    If that doesnt fix it, scan the engine after a good ride and check to see the engine coolant temp is normal 180-200*F. If it doesnt get there on a cool day or takes a long time to warm up, I would suspect the thermostat. Part is not expensive, but its a PITA to change.

    Hope this helps
    Joe
  7. andyprius

    andyprius Senior Member

    Joined:
    Feb 21, 2005
    Messages:
    2,212
    Likes Received:
    162
    Location:
    Sacramento, California.
    Your Vehicle Year:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    I went thru this same thing. After changing coolant and inverter pump. Bled everything extensively. Inverter bleed was no problem. Engine bleed was trickier until I found the 6mm bleed valve. End result: Around town short trips 68 F at radiator. Long trip temps are 106 F, that is with a partial grill block. I have come to the conclusion that all this is normal, that the car has varying temperatures in various areas as needed. One does not notice these things until they arise and one gets involved. My car is not overheating, heater and AC are working fine. You are correct in not noticing any turbulance at the radiator fill spout, as in a normal car. I think the three way valve and the various sensors and the ECU involved does a incredible job of maintaining highly efficient engine temps. Beyond our comprehension!
  8. 2009Prius

    2009Prius A Wimpy DIYer

    Joined:
    Mar 25, 2009
    Messages:
    2,653
    Likes Received:
    437
    Location:
    USA
    Your Vehicle Year:
    2009 Prius


    Indeed it is beyond me how the coolant temp could drop from ~ 180 F at the ICE down to 106 F at the radiator. :confused: Smells really fishy. :rolleyes:
    1 person likes this.
  9. andyprius

    andyprius Senior Member

    Joined:
    Feb 21, 2005
    Messages:
    2,212
    Likes Received:
    162
    Location:
    Sacramento, California.
    Your Vehicle Year:
    2012 Prius Plug-in
    Model:
    Plug-in Base


    There is no overheating, no red triangle ????:confused: I never measured 180F, and can only assume at this point that the thermostat is working, when I get a IR meter then I will only know the temp at the thermostat location but not if it is opening???
  10. andyprius

    andyprius Senior Member

    Joined:
    Feb 21, 2005
    Messages:
    2,212
    Likes Received:
    162
    Location:
    Sacramento, California.
    Your Vehicle Year:
    2012 Prius Plug-in
    Model:
    Plug-in Base


    My own theory is that the thermostat is never fully open, tied in with the fact that the car is cool running anyway it is possible that when the temp reaches opening point, it does open, a small amount, engine cools a small amount and thermostat closes again. In six years now I have experienced only mildly warm temps and slight pressure at the radiator fill point.
  11. Joe 26

    Joe 26 Member

    Joined:
    Feb 20, 2008
    Messages:
    240
    Likes Received:
    35
    Location:
    Columbus, Ohio
    Your Vehicle Year:
    2010 Prius
    Model:
    III
    I wonder what happened to the OP?
  12. andyprius

    andyprius Senior Member

    Joined:
    Feb 21, 2005
    Messages:
    2,212
    Likes Received:
    162
    Location:
    Sacramento, California.
    Your Vehicle Year:
    2012 Prius Plug-in
    Model:
    Plug-in Base


    That's always a puzzling phenomenon, they just drop dead like flies, I guess? :D
Similar Threads: Radiator coolant
Forum Title Date
Gen II Prius Care, Maintenance and Troubleshooting Radiator Coolant Leaking a little bit, add black pepper powder? Mar 30, 2014
Gen II Prius Care, Maintenance and Troubleshooting Radiator coolant help! Apr 16, 2012
Gen II Prius Care, Maintenance and Troubleshooting About to tackle the inverter and radiator coolant Mar 29, 2011
Gen II Prius Care, Maintenance and Troubleshooting HELP - Quick answer needed....Inverter fluid vs radiator coolant? Dec 1, 2008
Gen II Prius Care, Maintenance and Troubleshooting 12v battery and radiator coolant life expectancy? May 13, 2008