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

ICE coolant level: how do I know it's full?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by SRQ, Mar 10, 2013.

  1. SRQ

    SRQ Member

    Joined:
    Jan 25, 2013
    149
    55
    0
    Vehicle:
    2008 Prius
    Model:
    N/A
    This has to be a "classic thread", but here's a really silly question:

    How do I know if my coolant level is full after changing it? I drained my ICE coolant and then refilled it via the black radiator fill tube. How do I know when it's full?

    I also added some into the white plastic tank, but from what I can tell, it's just a reservoir for fluid that may boil over.

    I drove my vehicle after adding a gallon of the fluid (I drained about that much out) and I got a red triangle with the "Problem" on the display screen followed by an orange thermometer.
    When I ran the heater on high, nothing happened. It didn't get warmer ever.

    This is my first time changing the fluid and I'm a little confused as to what's going on. There's so much scattered information on here that it's difficult to sort through, and many of the writers tend to go off on irrelevant tangents and add unnecessary comments that make their guides hard to follow.
     
    #1 SRQ, Mar 10, 2013
  2. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,809
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    You have air trapped in the ICE coolant loop. Very common complaint.

    Its difficult for a novice to replace the ICE coolant and not get air trapped in the system. The CEL light and the "Problem" with the thermometer and the cold hose confirms this. The CEL is because you have overheated the engine due to the air trapped in the cylinder head. Be careful here as this car has an aluminum head and easy to damage with an overheat.

    You can either take it to the dealer to have it purged correctly or you can do it yourself by tricking on the CHRS thermos power relay causing it to pump and hopefully the air will cycle out. Its very hard not to end up with air trapped without cycling that thermos.

    The DIY method is to jack up the front of the car as high as you can. The reason air is getting trapped is the cylinder head is higher than the radiator. Common on modern cars. Take off the radiator cap. jack the front end way way up and put the car in inspection mode and let the engine run. In Inspection mode the engine will continue to run.
    Watch the coolant level in the rad and top it off as needed.
    You'll know if the air gets out as the coolant level will drop substantially.

     
    #2 edthefox5, Mar 10, 2013
  3. SRQ

    SRQ Member

    Joined:
    Jan 25, 2013
    149
    55
    0
    Vehicle:
    2008 Prius
    Model:
    N/A
    How would I know if I damaged my head? heh

    Would putting my vehicle up on ramps be an acceptable substitute for jacking it up, and should I bypass the water pump relay and force it to run? What about the allen head air valve on the drivers side of the radiator?

    Thank you so much for your help! I'm concerned that the few miles I've driven my vehicle may have damaged it, but I haven't noticed anything different...
     
    #3 SRQ, Mar 10, 2013
(You must log in or sign up to post here.)