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Technical Another stupid overheating question...sorry.

Discussion in 'The Hokey Ass Message Board' started by southerncad, Jul 31, 2017.

  1. southerncad
    Joined: Feb 5, 2008
    Posts: 766

    southerncad
    Member

    OK, so this may be a stupid question, but here goes, the temp gauge in my ’49 cad (original 6v with a Runtz) quit working, so I thought I’d install a manual gauge to see what actual temps the motor is running at. So I installed the temp probe in the back of the intake manifold, where the old electrical sensor was, and now it is overheating...and never did before!
    Now at 50 mph it’s at 200 (new 195 thermostat) when I slow down in traffic it climbs to 220, and higher if it idles very long. Then pukes into the overflow when I cut it off, never did this before. I can’t see how that temp probe could be causing the problem, but whadda’ I know. The engine is a ’77 Olds 350 with a mild cam, and hot ignition, otherwise stock, and is running the original ’49 radiator that has been flushed etc, and a big electric puller fan that will hold a shop rag up to the radiator, and it runs all the time. Any ideas/info would be appreciated.
     
    chryslerfan55 likes this.
  2. Joe H
    Joined: Feb 10, 2008
    Posts: 1,023

    Joe H
    Member

    Likely got air in the system when messing with the sensors. Figure how to bleed the system and the over heat will go away.
     
  3. Mark Roby
    Joined: Sep 29, 2015
    Posts: 96

    Mark Roby

    Agree with Joe. Sometimes you can squeeze the bottom hose with it running to push the air out. Turn on the heater and let everything circulate. Check the level after all that.


    Sent from my iPhone using Tapatalk
     
  4. sunbeam
    Joined: Oct 22, 2010
    Posts: 5,190

    sunbeam
    Member

    Or the old gauge lied.
     
    Hnstray and Jalopy Joker like this.

  5. Jalopy Joker
    Joined: Sep 3, 2006
    Posts: 26,430

    Jalopy Joker
    Member

    recent past flushed out cooling system and have correct coolant mix? correct working rad cap & thermostat?
     
  6. Slopok
    Joined: Jan 30, 2012
    Posts: 2,628

    Slopok
    Member

    Just for the heck of it reinstall the old thermostat, if that's all that's been changed. Problems usually rear their ugly head after the last change that was made if it wasn't doin it before!
     
  7. rustyangels
    Joined: Sep 28, 2010
    Posts: 178

    rustyangels
    Member

    I've had some problems with air in the system, my radiator sits lower than the heater core assembly in the '65 C10, so I purchased a cool funnel to burp the air out in about fifteen min, look up the Lisle 24680
     
  8. Mark Roby
    Joined: Sep 29, 2015
    Posts: 96

    Mark Roby

    Another thought. Was the thermostat you removed a 195 degree? Although as I read your post, you may have done the thermostat prior to the gauge and did not have a problem


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  9. southerncad
    Joined: Feb 5, 2008
    Posts: 766

    southerncad
    Member

    Thanx for the replies, but the old electrical gauge died, would not register at all, put in a new thermostat after the overheat problem started, thought it might be the problem, and radiator cap is correct, only change was the new temp probe.....will try and burp the system again.
     
    Mark Roby likes this.
  10. Happydaze
    Joined: Aug 21, 2009
    Posts: 1,121

    Happydaze
    ALLIANCE MEMBER

    Puking is normal when a system has been filled up and doesn't have a recovery system - the expanded water has to go somewhere. Maybe you just need to allow it to settle down? Keep topping it up (because you believe it has overheated) and it'll keep puking. Sure the numbers are getting kinda high-ish, but ok-ish nevertheless, but you didn't really know what they were beforehand anyway? And what's already been said, air lock etc. You could test the thermostat and if necessary replace with a lower value (again tested).
    Chris
     
  11. What are you running for the stock, belt-driven fan? Stock blade, flex fan, fan clutch...?
     
  12. proartguy
    Joined: Apr 13, 2009
    Posts: 484

    proartguy
    Member
    from Sparks, NV

    The '49 Cad shop manual indicates the water level in the tank is 2.25 inches below the top of the filler neck when cold, 1.75" when the coolant is "at the normal operating temperature of 170 degrees". I believe they used a 180 degree thermostat with a 12 to 15 pound cap. I would suggest running a 180 thermostat and not filling the tank up too much.
     
    Last edited: Aug 1, 2017
  13. Mark Roby
    Joined: Sep 29, 2015
    Posts: 96

    Mark Roby

    That was my point on the thermostat. If the thermostat that was removed was not a 195, I wouldn't have replaced it with one. 180 or 185 max IMHO


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  14. proartguy
    Joined: Apr 13, 2009
    Posts: 484

    proartguy
    Member
    from Sparks, NV

    So.... did you fix it?
     

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