1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Coolant leak after replacing heads

Discussion in 'Engine & Performance' started by chris44nala, Sep 10, 2019.

  1. chris44nala

    chris44nala Junior Member

    Posts:
    3
    Likes Received:
    0
    Joined:
    Sep 9, 2019
    Location:
    Limestone County Alabama
    First Name:
    Chris
    Truck Year:
    1978
    Truck Model:
    GMC Sierra
    Engine Size:
    350
    Hi,

    So, I bought some heads for my 78 GMC and finally got the thing back together. All seemed well at initial startup. Oil pressure, good. Coolant temp good. Then my worst fears were realized. Billowing white smoke after a short drive. Got it home after fumigating the neighborhood and parked it.

    The question is what is the best way to determine where the leak is? Also, is it possible that it is an intake manifold gasket problem?

    Thanks for the help,

    Chris
     
  2. Frankenchevy

    Frankenchevy . Supporting Member

    Posts:
    3,031
    Likes Received:
    2,316
    Joined:
    Jan 3, 2018
    Location:
    usa
    First Name:
    Jeremy
    Truck Year:
    old
    Truck Model:
    pickup
    Engine Size:
    8 cylinder
    Water in oil may be an intake manifold problem. But water in the combustion chamber points to head gasket or cracked head.
     
  3. chris44nala

    chris44nala Junior Member

    Posts:
    3
    Likes Received:
    0
    Joined:
    Sep 9, 2019
    Location:
    Limestone County Alabama
    First Name:
    Chris
    Truck Year:
    1978
    Truck Model:
    GMC Sierra
    Engine Size:
    350
    Thanks. Kinda figured. Pulling apart for a postmortem in a few days.
     
  4. Rusty Nail

    Rusty Nail Whatever! Supporting Member

    Posts:
    4,512
    Likes Received:
    2,302
    Joined:
    Jan 29, 2015
    Location:
    MAGA Country
    First Name:
    Rusty
    Truck Year:
    1977,1988
    Truck Model:
    C20, K5
    Engine Size:
    350, 350
    You performed a final tightening during assembly? I would check the torque wrench before I started killing new gaskets. :killer:
    Absent sealer around the coolant passages is a big no-no :nono:

    If those checks fail..that's not promising.
    Good Luck.
    Hope this helps!
     
  5. Rickf

    Rickf Full Access Member

    Posts:
    77
    Likes Received:
    38
    Joined:
    Jul 29, 2017
    Location:
    Grafton NH
    First Name:
    Rick
    Truck Year:
    1974, 1954 & a 1937
    Truck Model:
    K20
    Engine Size:
    350
    Air bubbles in the radiator is another indication of head gasket problems.
     
    Wumbo likes this.

Share This Page