Slow fuel leak?

Discussion in 'General Chevy & GM Tech Questions' started by ejj, Aug 26, 2009.

  1. ejj

    ejj New Member

    I have a 2005 Tahoe Z71, 5.3L engine. Over the last week or so, I've noticed a faint fuel smell when outside my truck. In addition, the car has had a hard time starting in the mornings. Today, I turned the car to the "run" position for about 10 seconds before starting the car, and everything was fine.

    With past cars that I've owned (non-GM), turning the car to "run" powers the fuel pump which pressurizes the system. Is the same true with this truck?

    If so, it would seem that I have a very slight fuel leak. I looked under hood at the fuel rail, and I didn't see anythign obvious. Are there fittings/locations that would typically be prone to this with these vehicles?

  2. tattooed4life

    tattooed4life Epic Member 5+ Years 500 Posts

    Yes turning your key to the on position pressurizes the system. Check along the frame were the fuel line runs to see if it has any spots where it may have rubbed on the frame. Also check the fuel filter which will be along the fame rails. There are also fittings on top of the tank but you would have to drop the tank to inspect those. However you can inspect the areas of the tank you can see for any run marks were fuel may have leaked out and if it appears to be the tank then drop it and go from there.
  3. ejj

    ejj New Member

    There are no leaks large enough to drip onto the ground, so hopefully it isn't something on the top of the tank, as that would be difficult to trace.

    Where along the frame rails is the fuel filter located? How is it fixed inline? I've owned Nissans that simply use high-strength hose clamps. Is this fuel filter clamped in line, or does it have hard fittings?

  4. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    If you have a leak on the tank side of your fuel system you should have an EVAP trouble code.If you have no codes the leak will be on the pressure side of the system beyond the fuel pump. Have you checked for codes?
  5. ejj

    ejj New Member

    Not yet. I'm on the road for work. I do have a CEL, but that turned on at the same time I experienced "problems" with the 4WD system. I assumed they were related.

    I've noticed the fuel smell for a little over a week, and appear to lose fuel pressure overnight, which leads me to believe that its a problem on the pressure side.

    Where is the fuel filter? Smell seems strongest around the rear door. Again, I haven't gotten under there an looked yet...
  6. ejj

    ejj New Member

    Read the codes today. P0446, which is an EVAP code. Typically, this is related to a vent blockage it sounds like. Could this contribute to this potential fuel leak that I have?

  7. grimreapersshadow

    grimreapersshadow Rockstar 100 Posts

    you proalby dont have a fuel filter on that model alot of the newer ones its in the tank with the pump
  8. Z71_guy

    Z71_guy Epic Member 5+ Years 1000 Posts

    your truck should have a in tank non serviceable fuel filter
  9. ejj

    ejj New Member

    Well that would explain why I've never seen one I suppose.

    That being said, anyone have an idea of a probable location of a slow leak?
  10. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    This is your problem. You have a leak not a blockage. The leak can be impossible to see because what's leaking is fumes or hydrocarbons as it's called.

    If you do a search here on this forum you can find some info on cleaning the canister vent solenoid rather than replacing it.

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