loosing anti-freeze and dont know where

Discussion in 'GM Powertrain' started by nvyseal11, Nov 1, 2007.

  1. nvyseal11

    nvyseal11 New Member

    I have an 03 silverado 1500 with a 4.8 and i seem to have a leak someplace and i dont know where. Every few days i have to top up my anti-freeze. Ive looked for leaks from a cold start and then when it has been running for awhile and i cant seem to find any leaks. Thats what worries me. I dont have to add much but i do have to top it up every few days. Any ideas if this truck has a water pump issue.

  2. Cableguy

    Cableguy Epic Member 5+ Years ROTM Winner 1000 Posts

    My word for today is "Head gasket"...can you say head gasket...I knew you could. Sorry too much Mr Rogers when I was a kid. Does the exhaust in the morning seem a little white and fluffy?
  3. JayMack75

    JayMack75 Former Member

    Check freeze plugs as well. When cold you will see very little or no leak. When hot the "leak" burns off, so no evidence. Another thing that you could check is behind the intake next to the firewall. My old chevy truck had a leak there, and it was hard to diagnose.
  4. FireRed

    FireRed Rockstar 100 Posts

    Just an idea are you checking it hot or cold? You may or may not have a problem the level will drop when cold and rise again when hot. you may be adding what the system has to push out due to expansion.
  5. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    The first thing I would do would be to put a pressure tester on the radiator and see what you can with the cooling system pressurized cold. Most external leaks (unless they only occur hot) can be found this way. I've borrowed Autozones tester several times, I don't know if someplace like Canadian Tire does the same in Canada or not.
  6. unplugged

    unplugged Epic Member 5+ Years 1000 Posts

    Page down in this GMTC thread you will see my post regarding cooling system leaks. As Mr Shorty suggested, you should perform a pressure test. You can get your own tester for under $50.00 A pressure tester will reveal any external leaks, and if it loses pressure and you don't see an external leak, then you know you have a more serious internal leak, which could be head gasket or leak in the block, radiator or intake manifold.

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