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stvhans's avatar
stvhans
Explorer
Jul 19, 2014

Smell Gas Fumes

I have a 2004 Winnebago Itasca Class
A motorhome with about 48,000 miles.
Just started a 6 week trek and stopped in Big Timber, MT after having filled up the rig about a 100 miles back. Topped it off real good.
when I got out I smelled gas fumes and thought it might be coming from the generator. Nope, not that. I rolled under the Itasca and it smelled like the fumes were coming from around the gas tank. Did not see any gas dripping, a small area near the top of the gas tank seemed to have what appeared to be stains (from gas?). I called my buddy at Camping world in Nevada and he was talking about evaporative hoses getting cracked or something. The only thing I really understood was to have a good time and bring the rig when I get back to town in August. I am not too concerned but don't want to blow up either. Does anyone have any further insight into this dilemma.
Thanks in advance for your consideration

Steve
Class A

7 Replies

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  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jul 21, 2014
    Todays vehicles used closed gas tanks with a charcoal canister near the engine that provides the vent, Gasoline fumes are thus sucked into the engine, the ECC (Computer) senses this (Senses the engine is running rich) and adjusts for it so you do not loose to evaporation.

    NOW: often there is a recirculation system where fuel pumped out of the tank is returned to it via some pressure regulation, This prevents vapor lock by the way.

    There are lots of hoses and such involved with all this and they can crack, there is also the grommet where the filler tube enters the tank, plus tanks themselves have been known to leak (This at least would cause dripping which you should notice)

    So long as the fumes do not reach the magic range of concentrations there is no danger but you should have it checked when you get home.
  • John_Wayne's avatar
    John_Wayne
    Explorer II
    Jul 21, 2014
    Dose your generator run all right? On mine it was the fuel line for the generator that had a crack in it would leak fuel and the generator would not run right air getting in fuel line. I dropped my tank and replaced the fuel line with rubber fuel injection line problem solved.
  • Born_To_Travel's avatar
    Born_To_Travel
    Explorer
    Jul 20, 2014
    The problem with filling your tank that full in hot weather is the gas in the underground tank is like 68 degrees and after you fill the tank completely full it warms up to the ambient temp and expands and if it has no where to go it does what you describe...
  • stvhans's avatar
    stvhans
    Explorer
    Jul 19, 2014
    Thanks for all the responses I received on this.
    I crawled under the rig and had a look around.
    The fill hose and vent hose looks like it is not cracked or leaking.
    However, I did notice that what looks like a small amount of gas has seeped from somewhere on top of the gas tank part of the way down the side. It would seem to suggest something similar to the last person responding that it might be a cracked vent line on top of the gas tank which I cannot see without taking the whole gas tank out. That is something that will have to wait till I get home.
    thanks again for everyone's response.
    Steve
  • olfarmer's avatar
    olfarmer
    Explorer II
    Jul 19, 2014
    It could be any of the things previously mentioned above. If you filled it really full that could have made gas get to a cracked or loose line. Try not filling it quite full for the rest of your trip until you can get it checked out.
  • Lt46's avatar
    Lt46
    Explorer II
    Jul 19, 2014
    The top of my F53 tank had a vent line that ran forward to the charcoal canisters under the hood. Might be a crack there.
  • MountainAir05's avatar
    MountainAir05
    Explorer II
    Jul 19, 2014
    You have a fill hose around 2" and a Vent maybe 3/4". If it is loose or cracked then you would smell gas fumes. Check them both. The fill must be a fuel type hose, The vent can be a heater hose, since it does not transfer fuel. Post if Ford or Chevy for more info

    I have a 99 and replaced both about 5 years back, due to cracking.

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