boiling water reservoir

Discussion in 'ENGINE' started by myk291, May 11, 2009.

  1. myk291

    myk291 Fresh Recruit

    hi guys! what might cause the water reservoir of my car to boil and overflow after turning off the engine after driving? has anyone experienced this? thanks in advance!
     
  2. Jay

    Jay Admin

    The cooling system pressurising like that means it is not functioning effectively. The reason could be a number of things, these are in order of cost (cheapest first) :

    - Airlock in the cooling system
    - Blockage in the cooling system
    - Defective Radcap (added by AlexGT)
    - Sticking thermostat
    - Blocked radiator
    - Failing waterpump
    - Failing headgasket

    The fact that it is overheating means that damage could be happening already. Until you work out what is causing it keep a stern eye on the water level (in the radiator). I would check it before every journey.

    Jay
     
    2 people like this.
  3. Phil

    Phil Super Moderator

    100% jay

    just to add:
    my car never showed any temp change (stock temp gauge wont give you any indication that there is an issue till its too late)

    the car was using some coolant regularly needed topping up a small amount.

    then eventually she blew the headgasket or at least thats the assumption white smoke everywhere and temp gauge off the clock. :(

    so worth keeping an eye on and getting an issues addressed whether it be headgasket or blocked radiator ASAP :)

    all the best.

    Phil
     
    1 person likes this.
  4. glanzanut

    glanzanut Paid Member

    jay has quoted you happy there mate as its sound advice from him there. if its pushing out a lot of air bubbles in the expansion tank as well then head gasket could be suspect :freddy:
     
  5. alexgt

    alexgt Registered User +

    this could also be due to the rad cap, the cooling system is always under pressure this keep the coolant temp below boiling if the cap is releasing pressure early this will cause water to boil and come out of the over flow on the bottle!
     
    1 person likes this.
  6. Jay

    Jay Admin

    LOL knew I missed something in the list, nice backup there Alex :cool:

    Yes the rad cap could cause issues if it is not operating properly. It should go before the thermostat in terms of cost.

    Jay
     
  7. myk291

    myk291 Fresh Recruit

    i would just like to add that although the water reservoir boils and overflows every time i turn off the engine, the temp gauge remains steady at normal running temperature and never overheats. by the way, how would i know if the rad cap is already defective and needs replacement? thanks for the inputs guys!:)
     
  8. jayc-glanza17

    jayc-glanza17 Paid Member

    you checked for leks mate, mine did this when thermostat pipe cracked.
    check for leaks as well as what jay says.
    just hope your fan comes on too?
     
  9. Jay

    Jay Admin

    The temp gauge in the dash cluster isn't accurate at all mate. It'll only rise above the normal point when the coolant is seriously hot. I don't put much stock in the reading - it could be over 100 degrees before it'll shift.

    Follow the list above as it's in order of cheapest/easiest first.
     
  10. GTti

    GTti Paid Member


    As above try replacing the radiator cap first, they're two way and not only let excess pressure out, but should also the vacuum in the system when it's cooled should suck fluid back into the radiator.
     
  11. iamlegend

    iamlegend Registered User +

    yep this happend to me, i was still using the stock rad cap so i changed it for a buddyclub 1 and it solved the problem, the stock caps are crap tbh
     
  12. i HAD THIS, TRUST, EMPTY YOUR RADIATOR COOLANT BOTTLE IF ITS REALY CLOSE TO THE TOP AND MAKE SURE THE RAD ISNT TOO FULL, THIS IS WHAT CAUSED MINE. IT WAS OVER THE FULL MARK HAHA
     

Share This Page