Gas smell while wheeling....anyone else...

[wfo9]

Ok, this is a bit odd.

I've wheeled my truck more times than I can count. Had it in all kinds of crazy off camber, steep and tilted situations... Ran it on 105+ days as well as in the 20s...

So today I went out for some very casual wheeling. Had a pretty full tank.. Mainly just putted around on super easy trails the entire day since I was letting my daughter get some time behind the wheel... outside temp was unusually warm for this time of year... maybe *80

I kept smelling gas all day, and one guy in the group...a 3rd gen asked me why he could see fumes coming out of his fuel door. I just said IDK keep an eye on it. Figured it might be something with his EVAP.

At the end of the day a few of us went off to play on one trail that offered some moderate challenges. I went up a very steep ledge and so did the other 5th gen. After that I was about to take another very difficult section and I started to really notice a strong raw gas smell. It seemed to be coming from my truck, but also his. We were sort of confused why we were both suddenly smelling gas fumes from our trucks.

Decided to skip the next scary section and went a little further down the easier part of the trail, but that gas smell continued as I ran my truck. It would eventually subside once shut off. Same with his. It was so strange. We could both see fumes coming out our fuel doors with the trucks running. The smell was strong enough that it was a little scary... I would not have allowed anyone with a cigarette... near my truck.

Gas caps were tight... We both had about 3/4 of a tank.

Finally got on level ground and it seemed to subside as we kept moving. Once off the trail the smell was gone completely.

I did notice that the air was oddly still. There was no breeze at all. And dust from the dirt road leading out of the trails was just suspended in the air not moving at all. It gave the light coming through the trees a very unique look. I don't ever remember the air being that still.

Still... the EVAP should not be letting these fumes out. Any ideas? Two 5th gens having a malfunciton on the same day at the same time....Not really possible, Must be something else.... I'm wondering if something about 4lo keeps the EVAP purge valve from running....

Just really shocked I have never noticed a gas smell before while wheeling. I was convinced I had done something to my tank at first.

Thinking more about it... both our trucks had just climbed uncomfortably steep sections just before we noticed it. That is the most likely cause, but I've done many similar ones before and never remember any raw gas smell at all.

 

[Jeremy556]

I've noticed it as well. Never observed vapors from the fuel door area, but haven't really looked, either. Smell has never been strong enough that I have looked into it further than doing a visual on the underside to check for leaks. All of the times I can remember were high ambient temps, 90F+

 

[JEMP1003]

I checked when I got home and the smell is gone. I'll be checking the next few days to see if it happens again.

 

[wfo9]

I checked when I got home and the smell is gone. I'll be checking the next few days to see if it happens again.

Yep, no more smell on mine either.... I think it was the high angle on that ledge we did combined with the high ambient temps... It sure was fun though LOL

I was running my AC all day..... and almost never shut the motor off.

I have not looked into the return system on the 4runner yet, but they all more or less recirculate fuel up to the rail and back (where it gets heated up). This just accelerates the vaporization in the tank... but again the EVAP system should be sucking those fumes into the motor.. Maybe there is some type of vent in the rear that goes under certain conditions....IDK, It was odd for sure.

 

[wfo9]

I've noticed it as well. Never observed vapors from the fuel door area, but haven't really looked, either. Smell has never been strong enough that I have looked into it further than doing a visual on the underside to check for leaks. All of the times I can remember were high ambient temps, 90F+

Yea, my very first thought was... my gas tank skid failed and put a small hole in my tank.... But I could not see any new hits or major deformations...

Right now,,, I'm chalking it up to an oddball situation and nothing to worry much about.

The only reason I looked at the fuel door was that the guy in the 3rd gen 4runner had mentioned he saw his doing it earlier in the day. And sure enough.. both of ours (JEMP1003 and mine) were looking like an open gas can of sorts...

 

[Danimal]

Strange. Only instances of this that I've experienced is at high altitude or high ambient temps. Did either of you open your gas cap? This will drop the pressure in the tank and if the fuel is hot enough (from ambient and return fuel flow) it'll cause rapid boil off. I've heard stories of guys boiling off a quarter of a tank, but only after a really long day at altitude. The 80 series forums have lots of threads on this.

 

[STX4Runner]

@wfo9. This is maybe unrelated, but maybe not. Yesterday I was watering a plant in my backyard in an old whiskey barrel planter that had been sitting in the sun all day and as the wood got wet water vapor was rising from it. Really weird. I didn't think anything of it at the time, but it was really still yesterday; not a breath of wind. I'd suspect it was something to do with the high temps yesterday combined with no wind and very dry air.

 

[1engineer]

I have smelled it a few times as well. My logic was "There has to be a vent to outside air somewhere in order for the fuel system to operate. If it is vented to outside then it is possible for gas smell to happen in certain situations. FYI the last time it happened to me was a ditch crossing on a beach. It was hot, tank was near full and the 4Runner went from leaning to the right to leaning to the left quickly. I caught a wiff of gas (windows down, low speed) and figured it just sloshed up somewhere into the atmospheric vent enough to let a bit of vapor out, hence the smell.

 

[wfo9]

@wfo9. This is maybe unrelated, but maybe not. Yesterday I was watering a plant in my backyard in an old whiskey barrel planter that had been sitting in the sun all day and as the wood got wet water vapor was rising from it. Really weird. I didn't think anything of it at the time, but it was really still yesterday; not a breath of wind. I'd suspect it was something to do with the high temps yesterday combined with no wind and very dry air.

Yea, I will say the weather was very strange in the late afternoon. I can never remember it being that dry, warm, and still all at the same time. Plus the ground was still cool, so no air currents at all.

Maybe all the stars just aligned....

 

[wfo9]

I have smelled it a few times as well. My logic was "There has to be a vent to outside air somewhere in order for the fuel system to operate. If it is vented to outside then it is possible for gas smell to happen in certain situations. FYI the last time it happened to me was a ditch crossing on a beach. It was hot, tank was near full and the 4Runner went from leaning to the right to leaning to the left quickly. I caught a wiff of gas (windows down, low speed) and figured it just sloshed up somewhere into the atmospheric vent enough to let a bit of vapor out, hence the smell.

After a little more research... I think it was somewhat normal, but a strange combination of things... The EVAP vent canister is up under the spare tire...

Here is my theory on the combination.
1. Somewhat full tank of gas...
2. Winter blend gas on an unseasonably hot day (lower vaporization point...)
3. Truck running all day and moving very slow (so fuel was most likely pretty warm)
4. Steep angles
5. No wind (very still dry air)

As far as the EVAP goes.. The vent is only suppose to let air in and should be shut off when the truck is not running. The purge valve should be putting a small vacuum on the tank while the motor is running, but there are all kinds of unknown parameters here...that I'm not sure about. For whatever reason... It seems like the vent was open when the truck was running and releasing fumes. I don't think it is suppose to do this, but perhaps the liquid fuel got into it on the angles.

BTW, my daughter did catch a video of me coming up the climb just before I noticed the smell.
<iframe width="560" height="315" src="https://www.youtube.com/embed/XffC62xhUvA" frameborder="0" allowfullscreen></iframe>

 

[FordyceCreek]

I am still trying to figure out how you went wheeling in TX and how on earth it could be 80 degrees right now! :help:

 

[wfo9]

I am still trying to figure out how you went wheeling in TX and how on earth it could be 80 degrees right now! :help:

You would be surprised how many good wheeling spots there are in Texas. You just have to go looking for them... And it's not all flat like most people think. It's actually extremely diverse. Texas is huge and beautiful, just not a lot of public land unless you drive way down to the south near big bend, or run down the beach where you can wheel for 70 miles on sand and get to extremely remote beaches.

I live pretty close to a 3k acre park in the hill country where I pay a yearly membership fee and can go everyday if I want... It's not on every corner... but many places do exist. Several big hunting ranches that open up for wheeling at different times of the year.. There are also some amazing granite rock crawling spots that provide Moab like terrain. Look up Wolfs Caves and K2 to get an idea.... It's a bit extreme for daily rigs though.

Oh, and it was 80 on Sunday, It's 50 now ;-) Will be 30 in a day or two.... Big swings here....

 

[Paulst2419]

You would be surprised how many good wheeling spots there are in Texas. You just have to go looking for them... And it's not all flat like most people think. It's actually extremely diverse. Texas is huge and beautiful, just not a lot of public land unless you drive way down to the south near big bend, or run down the beach where you can wheel for 70 miles on sand and get to extremely remote beaches.

I live pretty close to a 3k acre park in the hill country where I pay a yearly membership fee and can go everyday if I want... It's not on every corner... but many places do exist. Several big hunting ranches that open up for wheeling at different times of the year.. There are also some amazing granite rock crawling spots that provide Moab like terrain. Look up Wolfs Caves and K2 to get an idea.... It's a bit extreme for daily rigs though.

Oh, and it was 80 on Sunday, It's 50 now ;-) Will be 30 in a day or two.... Big swings here....

I live in Houston and apart from driving out to Hidden Falls, I can't find any good public places except for driving down the beaches. I did have a lot of fun down on South Padre Island. Other than that I just find random city owned plots of land and hope I don't get caught.

Oh and I've been in Nebraska for the past two days. Snowed in at my hotel wishing I had my 4runner with me

 

[wfo9]

I live in Houston and apart from driving out to Hidden Falls, I can't find any good public places except for driving down the beaches. I did have a lot of fun down on South Padre Island. Other than that I just find random city owned plots of land and hope I don't get caught.

Oh and I've been in Nebraska for the past two days. Snowed in at my hotel wishing I had my 4runner with me

I do not tolerate illegal off-roading. Just don't do it.

Sorry you live in H town, that place kind of sucks :bigok: but plenty of roads leading in and out....

Most of the spots are in central and West Texas. Like I said, you have to go looking for them and get involved in the off-road community to find out about most of the places. I know a guy in Houston who goes wheeling at a different spot almost every weekend (I can put you in touch with him) Again you have to drive a bit and have a pretty capable vehicle to hit most of the spots. They are not all well advertised and not open every weekend, but all 100% legal and extremely diverse. Most 5th gens would probably have trouble though. I would not take mine to many of the places (and its pretty darn capable). Just don't want to beat it up that bad or be limited to just a few trails.

A decent one to try from Houston that is public is Barnwell Mountain. HF also has some easy trails with some good views...
Barnwell Mountain Recreation Area