Results 1 to 10 of 10

Thread: Replaced heater core, only cool air coming out

  1. #1
    Junior Member Automotive Encyclopaedia
    Join Date
    Dec 2009
    Location
    Victoria
    Posts
    854

    Default Replaced heater core, only cool air coming out

    Hey all,

    Just finished a heater core on a st184 celica. To my dismay there is still only cool air coming out of the vent. Strangely enough one of the hoses going into the heater core is hot yet the other one is still icy cool...

    Im suggesting there is a block somewhere in the core/heater tap at the moment.

    I will check if its actually getting past the heater tap (by checking the hose just after it)

    Any suggestions on the topic?
    ZZT-231 Toyota Celica SX

  2. #2
    Current UZA80 owner Chief Engine Builder JustCallMeOrlando's Avatar
    Join Date
    Aug 2005
    Location
    Western Australia
    Posts
    4,152

    Default Re: Replaced heater core, only cool air coming out

    Sounds like the tap isn't working correctly. I'd be very surprised if the core was totally blocked. They usually leak before that.
    Teh UZA80 - Project Century - Remotely p00'd by association

  3. #3
    Junior Member Grease Monkey
    Join Date
    Apr 2007
    Location
    wilcannia NSW
    Posts
    140

    Default Re: Replaced heater core, only cool air coming out

    there may be air in the heater core. one way is to take off one of the heater hoses, then fill the radiator using a funnel which seals in the spout.

    the idea is to get a column of water a bit higher than normal to help push out the air. pour in water ( coolant ? ) until water comes out of the heater. put the hose back on and start 'er up. works wonders.

    hope this makes sense.
    so much stuff. so little time.

  4. #4
    Junior Member Carport Converter StuC's Avatar
    Join Date
    Oct 2005
    Location
    Victoria
    Posts
    1,792

    Default Re: Replaced heater core, only cool air coming out

    did you reconnect the cable for the cold/hot dial?

  5. #5
    Junior Member Carport Converter Dale's Avatar
    Join Date
    Sep 2005
    Location
    NSW
    Posts
    1,914

    Default Re: Replaced heater core, only cool air coming out

    its probably full of air, I've had systems take > 30 mins with the engine running before the heater spat out hot air again
    I am the sun

  6. #6
    Junior Member Carport Converter StuC's Avatar
    Join Date
    Oct 2005
    Location
    Victoria
    Posts
    1,792

    Default Re: Replaced heater core, only cool air coming out

    me too but only on nissans, fords, commodores, benzes, BMWs....never happened on a toyota for me.Random....

  7. #7
    Junior Member Automotive Encyclopaedia
    Join Date
    Dec 2009
    Location
    Victoria
    Posts
    854

    Default Re: Replaced heater core, only cool air coming out

    Thanks for the suggestions, it ended up being air in the system.

    The first time when I went to switch off the car with the cap off there was a huge burst of air come through,

    Then I went to rebleed the system just earlier and there was so many bubbles, ive never seen so much in a toyota before.

    I got to the car wash this afternoon and noticed I had left the top radiator hose was loose., I may have to bleed the system again to bring up the heat a bit (its still not quite boiling hot air yet)

    Rep to all the great suggestions thank you
    ZZT-231 Toyota Celica SX

  8. #8
    Junior Member Carport Converter Dale's Avatar
    Join Date
    Sep 2005
    Location
    NSW
    Posts
    1,914

    Default Re: Replaced heater core, only cool air coming out

    Over the course of 2 - 3 heat cycles it will purge the air via the overflow bottle.

    Generally to get water to flow up and through heater cores the system needs to be pressurized. Ie. the cap needs to be on
    I am the sun

  9. #9
    Junior Member Automotive Encyclopaedia
    Join Date
    Dec 2005
    Location
    Tallahassee, FL USofA
    Posts
    1,115

    Default Re: Replaced heater core, only cool air coming out

    Quote Originally Posted by trd_st184 View Post
    I may have to bleed the system again to bring up the heat a bit (its still not quite boiling hot air yet)
    It needs flow from RPM, pressure from being heated/capped won't matter in pushing out air.
    Fill it, drive it, top it off, that's it, and only dick around with bleeding if it can't be started & the customer isn't going to top it off.
    'I've scrapped better.' John stated when asked about the car by the guy with the silver tipped cowboy boots!

  10. #10
    Senior Citizen Chief Engine Builder "Z" UTE's Avatar
    Join Date
    Nov 2005
    Location
    ACT
    Posts
    3,059

    Default Re: Replaced heater core, only cool air coming out

    Heater core replacement 101, before connecting heater hoses back to the engine, use a garden hose to force water into the heater core and expell the air. Then connect all hoses, that is how the radiator repair shops do it.

    The humble 1.25 ltre PET softdrink bottle (screws into most radiators) with the arse end cut out is perfect for getting a column of water above any air entrapment points in an engine. Some engines actually have air bleed points near the thermostat, worthwhile checking your repair manual for tid bits like this.

    cheers Chuck.
    "What man can build, man can fix!"
    MS51Crown Coupe,
    GSV40R Aurion luxo tourer. One TA22 currently receiving some TLC prior to paint One RS56 Crown ute under construction, 2 x TA22's awaiting rebuilds. Toyota Crown RS47J ute in need of serious TLC. Toyota Crown Custom Wagon MS53 daily hauler stocko!

Similar Threads

  1. Heater Core Alternatives
    By Dom-AE71 in forum Tech and Conversions
    Replies: 24
    Last Post: 28-10-2007, 08:43 PM
  2. Sam-Q's 20V RWD Cooling System Guide
    By Sam_Q in forum Engine & Driveline Conversions
    Replies: 14
    Last Post: 27-03-2007, 05:08 AM
  3. Radiator question.. Core thickness/air flow
    By TurboRA28 in forum Tech and Conversions
    Replies: 33
    Last Post: 05-05-2006, 08:49 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •