Gas smell after off-roading

Anyone experience a gas or ethanol smell coming from drivers side rear door area (right above gas tank) after off-roading?

Drove my 4runner about 4hrs in 90-100° heat, then got on some trails. I was bouncing all over the place with an almost full gas tank. Afterwards I pulled off to air up, it had a strong smell of gas wafting up around drivers side of 4runner.

 

Most likely the fuel sloshed around and leaked around the cap? Have never experienced that myswlf tho. Worst case scenario you damaged the gas tank? Check for damage/watch out for leaks just to be sure.

Cheers!

 

Expansion. Has to go somewhere.

 

Yeah, expansion, and maybe angles and dangles off road are sometimes enough for the fuel to get out of the vents. I’ve noticed a smell when I get out of the vehicle if it’s parked on very inclined surfaces.

I guess that makes for a good argument not to top off the tank before an off road trip that you know will include steep angles. It’s probably not good when you can smell it, because it probably means the charcoal canister is getting soaked.

Eta: I don’t like to run so hard that’t I’m bouncing all over the place, but I suppose that by itself could be enough to slosh fuel to the vents or cap. But, as mentioned, check your skidplate for any large dents. The fuel tank is plastic and a large hit on the skidplate may be hiding a dent in the plastic itself. That would have definitely forced fuel out if it gets dented while full.

 

This just happened to me as what the OP is describing. I went offroading with a full tank of gas in Moab and now the smell of gas right around the driver side is quite evident.

 

How long ago was the trip. I’ve gotten gas smell off road on inclines, but it pretty much went away immediately. Did you notice actual spillage?

 

I’m interested to know where the fuel smell is coming from. My understanding is that the fuel filler cap is sealed. There’s a vent in the cap but it doesn’t go to the atmosphere. It goes either into the tank or to the charcoal canister. I’m not sure which. The charcoal absorbs the vapors. The canister is vented, but air is drawn in through the vent by engine vacuum, through the charcoal, pulling the absorbed fuel vapor out of the charcoal and into the intake manifold where it is burned off during the normal course of combustion. This is an area where my knowledge is very sketchy. Is the fuel smell coming from the charcoal canister’s vent? Because the full tank and the terrain have caused the charcoal canister to become saturated? I know there’s a purge valve and a vent valve but I don’t know how they behave. It’s all rather mysterious. Can somebody explain in detail? Or point to a video?

 

I may be wrong about this, but I would think that if you experience strong fuel vapors after abnormal maneuvers, the charcoal canister has received raw fuel which could damage it.

Having said that, recently after operating my Sequoia in very hot weather during city driving it had a strong gas smell when we returned home. I was unable to determine the origin of the smell. My guess was there may be a fuel pressure relief valve in the fuel delivery system on the engine?

 

Here is where I am with this....preliminary of course. Key variables or common things.

• High temperature outside
• High level of gas in the fuel tank AKA full
• Going over bumps or heavy offroading

My suspicion is that there is probably some sort or check valve in the line that prevents gas flowing back up again to the inlet, but....during High bumps or leaning the vehicle sideways, the gas is so much volatile than the liquid that it goes back thru the "the check valve" and that is the smell we get right around the area where we fuel up. I have been looking for a piping diagram or the exact drawings to verify the plumbing in that area but can't seem to find one. I just dont want to start tearing down this area just because .

Oh, add to this the Evap system piping which probably has dedicated line or bypass where these vapors go back to the fuel tank.

 

I haven’t looked at how any of this works, but my observations when jt happened to me was that the smell came from the driver side rear quarter area. Can’t truly be
more specific since I didn’t actually see any leaking on a cursory inspection (had better things to attend to at those moments lol).

 

That may track with the notion that the fumes are escaping from the charcoal canister’s vent. The charcoal canister is above the tear axle. I don’t know if the vent is nearby or under the hood. It’s too hot to go look. Maybe later.