Gen 3 boiling gas??

[offthepath]

This seems very weird and I'm not sure how it's possible, but fourwheeling today the gas in the tank of my Gen 3 montero was boiling. Full on rattling the Kettle boiling.

We were doing a tight trail that gained about 3000 feet of elevation in 8 miles, so it was steep but nothing crazy technical. Temps were in the 70-80s. Truck was in 4low, generally in 1st or 2nd. We stopped mid way and it was fine but about 30 minutes later I started to smell gas. We stopped for lunch and when I got out you could hear the gas boiling in the tank. It was a hard boil and it kept going for about 3-5 minutes after shutting it down. After lunch we kept going and it did not have any other issues (although not nearly as steep).

Has anyone ever experienced this? I ride dirt bikes and it's not uncommon for gas to boil in the tank, but it's because the tank is sitting on top of a hot engine. I don't see how the gas tank on the montero could get hot enough to boil 20 gallons of gas......weird. I felt the tank and it was warm like you would expect but nothing crazy.


On a side note, it sure is fun watching a jeep and Tacoma get stuck on a steep climb. Once they finally get up after much dickery, they eagerly watch the montero expecting the same challenge. It walked right up it,

 

[Toasty]

Boiling or bubbling? I've seen it a four times, something to do with the vapor system. The truck will eventually stall out too, we've had to run the things with the gas cap loose to get it off the trail or to camp. Seems to happen on elevation gains, i'm not sure of the cause but it seems to go away on it's own because everyone I've known to experience the issue never fixed it. I've seen it even fill the charcoal canister on a Gen 2 and pour out a ton of gas, interesting note it's been two 94 SR's and two Gen 3's...

 

[Rambo Penguin]

I’m following this because I had something similar happen. Same kind of set up. Off-road driving, elevation gain. Turned the car off. Heard a sound coming from the gas tank area. Kept happening for 30 minutes before I decided to start the car. Started r and ran it for 5 minutes and then stopped it and it went away. Very strange.

 

[IncorpoRatedX]

Also seen it happen, happed on the after-mod trail with Carlos last year. I think there's a purge solenoid or evap solenoid that can be related to it, but I'm just speaking from a fuzzy memory and second hand overhearing the conversation. it's not boiling, just a pressure thing.

 

[Rambo Penguin]

Yeah I don’t think it was boiling, but it did sound like it

 

[offthepath]

Thanks guys. I'll see if it happens again.

 

[Salonika]

I think this is related, I’m close to sea level and every now and then I experience a mystery sound right after startup, best I can describe it as is a whooshing, stirring air like sound coming from the gas tank. It only lasts about 5-10 seconds max. I’ve posted on it before. I’ll bet this is related somehow. Zero driveability problems.

 

[nwoods]

Had it happen in Big Bear Mtns and also up near Mammoth, long trail hill climbs, steady elevation gains, fairly warm summer weather.

 

[bugshield]

Sorry if you are offended by my revival of this old thread. I appreciated finding it.

Same happened to me today after rock crawling then a pretty steep 4k foot climb at about 90-100f. Freaked me out a bit! Fuel tank was not really hot to the touch and there wasn’t much pressure in the tank when I vented it after letting it simmer down. I wonder if it is boiling in the line that runs beside the cat on the passengers side? Maybe I need to carry an infrared thermometer to diagnose it.

 

[epyonxero]

I havent experienced this myself but if the fuel tank vent is blocked and a vacuum or near vacuum is pulled the gas could boil at low temperature from the drop in pressure.

 

[bugshield]

I havent experienced this myself but if the fuel tank vent is blocked and a vacuum or near vacuum is pulled the gas could boil at low temperature from the drop in pressure.

I think it was pressure rather than vacuum judging from the smell which indicates venting.

Another variable that I should have mentioned is that I had only travelled about 50-miles since purposely parking slightly nose-down when fueling up, as I always try to do, since I can put a couple more gallons in that way. There’s a big difference in capacity between parking nose-up and nose-down when fueling up!

 

[ChrisCosta416]

So your Gen3 Montero is leaking fuel when parked uphill, going up an obstacle or when it is hot outside?

Today we will be going over a Technical Service Bulletin (TSB)/Recall Issued my Mitsubishi Motors back in August of 2004. Technical Service Bulletins are issued by a vehicle manufacturer when there are several occurrences of an unanticipated problem. In this case a fuel leak. A recall is issued...

forum.expeditionportal.com

 

[bugshield]

So your Gen3 Montero is leaking fuel when parked uphill, going up an obstacle or when it is hot outside?

Today we will be going over a Technical Service Bulletin (TSB)/Recall Issued my Mitsubishi Motors back in August of 2004. Technical Service Bulletins are issued by a vehicle manufacturer when there are several occurrences of an unanticipated problem. In this case a fuel leak. A recall is issued...

forum.expeditionportal.com

Thank you for the info!