Fuel leak at the tank...

Discussion in '2005+ Mustang GT 4.6L Tech' started by TN05S197, May 3, 2019.

  1. TN05S197

    TN05S197 Junior Member

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    I have an 05' GT with just over 20K miles. Last weekend I backed out of the garage and noticed fuel smell and saw wet concrete. There was no fuel smell in the garage prior to starting the car. I looked under the car (with it idling) and fuel was not quite running but very fast dripping off of the bottom of the fuel tank cover. Needless to say I pulled back in the garage and shut the car off. The fuel continued to drip for a while with the engine off, then stopped.

    My guess is that the fitting from the fuel line to the fuel tank sending unit may have dry rotted or a fitting has become loose. This is a garage kept, weekend driven, never in the rain car. No rust anywhere on the car and there are no signs of mice in my garage at all so I doubt it's rodent damage.

    I'm assuming that the problem is a $2.00 part that's going to cost me a ton to have the car flat bedded down to my mechanic to fix. I've never dropped a fuel tank, but I'm assuming it's not that hard to do.

    Any other thoughts or has anyone experienced the same thing?

    Thanks for the help in advance.

    lowponytank1.jpg
     
  2. RLF9409

    RLF9409 My blood runs Ford blue!

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    I would check the sending unit.

    Remove the back seat and take off the black rubber cover to access.

    I would be willing to bet you may have a small critter making a home...or possibly dry rot.



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  3. TN05S197

    TN05S197 Junior Member

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    Thanks for the info on how to look at the top of the sending unit.
     
  4. RLF9409

    RLF9409 My blood runs Ford blue!

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    Please let me know what you find!

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  5. TN05S197

    TN05S197 Junior Member

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    The mystery deepens...see photos.

    I removed the lower backseat cushion and popped off the cover over the sending unit and nothing was there, no sign of any leak nor any cracks. I also smelled it, no smell around the sending unit opening. No sticky residue from dried gas. I turned the key to activate the fuel pump...nothing, no leak at the 90 degree fitting or where it goes into the tank. I didn't start the car, just pressurized the fuel system.

    I also checked the fuel filler hose from top to bottom, no leaks.

    You can see in the one picture of the fuel tank that fuel has run down the side from the top.

    The only thing I can think of is that some part of the fuel line has a leak between the 90 degree fitting at the sending unit on top of the tank where I can't see it. I'm assuming a 2005 car would have fuel lines that are compatible with ethanol mix fuels...right? That's the only thing that comes to mind is that possibly the ethanol mixed fuel has deteriorated the hose over time so there's a leak in it.

    SENDING UNIT.jpg TANK 1.jpg FUEL FILLER 1.jpg FUEL FILLER 2.jpg
     
  6. RLF9409

    RLF9409 My blood runs Ford blue!

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    Thats frustrating.

    Maybe next step is to drop the tank. And trace the leak.

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  7. Juice

    Juice forum member

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    Since it only leaks when there is fuel pressure, I would think the fuel line from the sender to the fuel filter needs to be checked. Fuel could be spraying up onto the tank and making it appear the leak is up high when it really is not. Have you checked the fuel filter? It may have rusted a pin hole.
     
  8. TN05S197

    TN05S197 Junior Member

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    After investing in an $85 video scope, the leak is a ruptured fuel line that runs on the front side of the tank before it turns and heads towards the engine. The way the fuel was spraying out of the line, it appeared to be coming from an area of the tank where there was no fuel line. Mystery solved.

    The rupture isn't from rodent damage, there are no chew marks, just the split in the line. I'm not sure how a car that spends it's life in a garage and only has just over 20K miles on it has a fuel line failure...but I guess it happens.

    Is there anyone that's replaced their S197 GT fuel lines? Seems like it will be very difficult without a lift. If there are any suggestions for replacement (upgraded) fuel lines online I'd appreciate it.

    fuel line 1.jpg
     
  9. RLF9409

    RLF9409 My blood runs Ford blue!

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    That's the way your car is telling you to drive it more!
    Glad you found the problem. Excellent opportunity to upgrade...

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  10. TN05S197

    TN05S197 Junior Member

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    Leak found....Not a defect, just stupidity at its finest.

    2019061495215343.jpg IMG_20190614_223459_315.jpg IMG_20190614_223459_317.jpg

    I finally had my car towed to my mechanic yesterday. This is where having a lift vs. a floor jack makes a big difference. Long story short, I could not have the car running while up on a floor jack to see where fuel was originating from. I was crawling under the car after it was done dripping to try and locate the source of the fuel.

    My mechanic starts the car, lifts it up and we both walk under the tank and immediately see the issue. Back story...I had Air Lift Performance installed on my car in January at a shop that does high-end builds. I saw their work, the cars look very impressive to me so I assumed all work would be done at a high level. Well...you know the old saying when you assume something.

    As you can see in the pictures, the guy that did the install decided to drill a hole in the seam weld of the fuel tank so he could put a zip tie through it to hold an airline.

    Now is when you hear the music from the Price Is Right when you lose a game on the show...we all know that tune.

    Who drills a hole in any part of a fuel tank? Well, this guy did and it made my tank leak.

    It reminds me of a saying that Mark Twain once said: "The thing about Common Sense is that it's not very common."

    Thankfully the tank doesn't need replaced. The hole was plugged with fuel tank epoxy. I only wish I had found it before I had it towed there, I could have saved myself $250 and fixed it myself.

    At least there was no weird tank defect and I can drive the car again.