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Head Gasket or Intake Gasket?

Discussion in 'GM Powertrain' started by sirchivalry, Nov 22, 2010.

  1. sirchivalry

    sirchivalry New Member

    Hope someone can help me. I have an '04 Z71 with 5.3. The other day when I started the truck, it started blowing alot of white smoke. It smelled like coolant and I noticed that my coolant was low. I checked the oil and it was fine.....no milkiness or moisture. I even drained it to make sure and it was okay.

    I have done some reading and have heard 2 things....the head gasket OR intake gasket.

    Can someone please help and tell me which one it likely is.

    thank you,

    JC
  2. k.daddy1

    k.daddy1 Rockstar 100 Posts

    Is the truck running hot? If it's just blowing white smoke and smells like anti-freeze, more than likely it's just an intake gasket.
  3. ippielb

    ippielb Epic Member 5+ Years ROTM Winner 1000 Posts

    Well, what symptoms does the truck give when driving? You can take a can of an aerosol spray of some sort (carb cleaner or similar) and spray it around the intake manifold to check for external intake manifold leaks.
  4. stephan

    stephan Rockstar 3 Years 5000 Posts

    X2 what KDaddy said, & if you want to look a little deeper, pull some spark plugs & see if there's some H2O/coolant on them. If it's a leak from water passage to intake port it may not be open to the outside so checking for vacuum leaks with the spray won't help you to find it. Also you might want to look for bubbles in the cooling system as this would indicate it is a head gasket...or worse, a cracked head.
  5. phoebeisis

    phoebeisis Epic Member 5+ Years 1000 Posts

    Intake manifold gasket failures are a lot more common that head gasket failures on GMs of all sorts.


    I would bet it was manifold-just based on likelihood-lot cheaper to fix than a head gasket also.It can be a DIY fix-the head gasket is a much bigger deal for a DIY guy.
    Some of the aftermarket suppliers claim their latest gaskets-their highest priced ones--$70 set-will not fail again-fancy syn rubber and steel gaskets.I used them-so far so good.
    Charlie
  6. dualdj1

    dualdj1 Rockstar 100 Posts

    This is the easiest test. A plug will look white (steam cleaned) on a cylinder that has a leaking head gasket.
  7. sirchivalry

    sirchivalry New Member

    WOW, thanks for all the replies

    Yeah, it started running hot the other day when I found out the coolant was low. Usually runs around 190, but went up to 220 so I shut it down. Again, thanks for all of the input. I am off next week, so I guess that would be a good time to tear it down. One more question......do I need to remove the fuel rails and injectors to take the manifold off. I don't think I will, but not totally sure.

    thanks again and have a Great Thanksgiving everybody,

    JC
  8. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    Hey guys - isn't the 5.3 a dry intake? No coolant?

    I'm looking at a pic of the gasket, only seeing the intake ports with sealing surfaces.
  9. I have the same problem on my '89 Burban 350. I am hoping it's the intake gasket. It'll burn white smoke and even miss for a short bit then once she warms up it burns off and runs fine, I don't think it is a head gasket, emotional support here to help me believe so is greatly appreciated, lol. Loose about a half gallon a month. Gonna run it till winter when I can't get the boat on the water then it will give me a project to do. By back aint lookin forward to hanging over the radiator for a few hours though. I also have heard rumorrs form elsewhere that the intake is the more likely culprit......
  10. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    Northport - your problem could be an intake gasket, but the TBI gaskets are not nearly as notorious for failing as the Vortecs are.

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