100 Caught fire & gas tank venting concerns (1 Viewer)

[mcewan13]

I just took a couple of hours to read through this thread. I have experienced this issue in both of my LC100s. On the lower milage one (135k), it happens semi-frequently. It happens at high elevations, rolling trails at low speeds, and highway speeds on hot days. It has even happened at sea level in early March (low 70s) while idling in stop and go traffic while crossing the MX/US border at Mexicali. I'm planning on checking the CC and associated valves first, but will likely be looking at shielding heat issues by cats (and possibly muffler). I have added a Magnaflow muffler and Dissent skids so I'm wondering if either / both of those issues have contributed to heat retention.

 

[2001LC]

Experiencing in both 03LC may be revealing clues in itself. I do think your EVAP approach is one they may both need. But make sure you get basics inline also.

First, you have been cleaning your radiators (all 3) fins right!

Radiator fins need cleaning! Alert Alert Alert

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added...

forum.ih8mud.com

In this thread the fuel boiling issues been kicked around a lot. There are different clues pointing to EVAP system. But most just need a good coolant service and a tune. It is looking like some will benefit from an EVAP system service as well. Seems more so, in the 03-07, when CC was moved to the rear.

Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen?

IMO, absolutely a hazard and should not be opened. Let the safety relief do it's thing (IE keep it closed). I understand the urge to vent it quickly, but best to just let it vent and if you've got liquid misting out prepare any onboard extinguisher you have. Mine vents under the hood from the...

forum.ih8mud.com

 

[PIPO]

It started happening to mine on long trips (one hour or more). This last trip, I half turned the cap about that thing was venting for a good 6 mins…that’s a long time.

 

[Rebele92]

That is my basic understanding as well - the cap is supposed to allow air to enter under vacuum conditions (night time, when the fuel cools off), but if the tank develops pressure, the pressure is supposed to exit through a valve and move to the charcoal canister where the vapors will eventually be aspirated with air for combustion. So is it the valve on the tank that is causing the pressure to build up to problematic pressures?

Bingo

 

[2001LC]

Thinking out loud:

If Charcoal Canister (CC) saturated (spent). Then it's ability to hold or allow vapor to pass through, is reduce or even stopped expect under very high pressure.

These spent CC are heavier than a new CC, as charcoal within is saturated with fuel. Old fuel in these CC. Tend to have a old fuel smell. Like fuel sitting in some old fuel tank for years. Often, we can smell this, while CC still in vehicle.

As we see and hear, vapors & hissing from gas tank cap area. This is fuel pressure builds in the fuel tank, rather than equalizing by vent. As pressure increases, it creates heat. Heat, result in expansion, creating more pressure. As we increase in altitude, barometric pressure decreases. Thus external pressure on tank decreases. High pressure moves to low pressure. Fuel start to boil, pressure becomes dangerously high in fuel tank, wanting out. As we climb in altitude, boil point temp decreases.

CC under normal opening condition, last a very long time. The million mile Toyota Tundra, still had the factory installed (as I recall). I know of an 00LX w/400K miles, with factory installed CC still working.

So why are some CC being spent/damaged, sooner rather than later. First and foremost; raw fuel entering them. How does this happen:
A) Over filled fuel tank.

1. Adding fuel, after auto shut-off of fueling pump handle. 2003-up OM, warns against this. Doing so can flood the CC.
2. Fueling on hot day, with cold fuel. Fuel heats to ambient temp, expanding in tank.
3. Engine & transmission running hotter than normal on hot days. Radiant heat from engine, CATs & transmission, asphalt along with high ambient temp. Heating fuel as it returns to tank and in tank, expanding fuel.

What to do:

1. First never overfill.
2. On hot days. Either don't fill up, to full. Or drive, after fueling to reduce fuel level. Giving room for expansion in tank.
3. Service coolant system is number one. In getting engine operating temp to normal. Making sure all 3 radiators free of debris (clean radiator fins). Clogged Radiator fins, cann't transfer heat efficiently away from coolant. These clogged fins, result in excessive operating temp of engine and transmission. W also need to, tune engine and flush transmission.

If a fuel boiling event, has happen. You can bet, CC damaged. If so, it needs replacing. But first, we must address why and correct. Or we risk, damaging another CC.

 

[Hugh Heifer]

I want to reiterate that I had over pressure issues and a terrible gas smell both inside and outside of the truck. I got a new gas cap and all was solved.
I consider myself lucky based on all I have read here but if you have any issues, that is a cheap part that does need refreshing from time to time.

 

[Eyedaho]

I want to reiterate that I had over pressure issues and a terrible gas smell both inside and outside of the truck. I got a new gas cap and all was solved.
I consider myself lucky based on all I have read here but if you have any issues, that is a cheap part that does need refreshing from time to time.

I also experienced a strong fuel smell for a few weeks and solved it with a new gas cap. I believe that issue was decoupled from the fuel boiling issue in very hot weather that I have experienced. My fuel smell would occur with the vehicle parked in hot weather.

 

[PabloCruise]

Thinking out loud:

If Charcoal Canister (CC) saturated (spent). Then it's ability to hold or allow vapor to pass through, is reduce or even stopped expect under very high pressure.

These spent CC are heavier than a new CC, as charcoal within is saturated with fuel. Old fuel in these CC. Tend to have a old fuel smell. Like fuel sitting in some old fuel tank for years. Often, we can smell this, while CC still in vehicle.

As we see and hear, vapors & hissing from gas tank cap area. This is fuel pressure builds in the fuel tank, rather than equalizing by vent. As pressure increases, it creates heat. Heat, result in expansion, creating more pressure. As we increase in altitude, barometric pressure decreases. Thus external pressure on tank decreases. High pressure moves to low pressure. Fuel start to boil, pressure becomes dangerously high in fuel tank, wanting out. As we climb in altitude, boil point temp decreases.

CC under normal opening condition, last a very long time. The million mile Toyota Tundra, still had the factory installed (as I recall). I know of an 00LX w/400K miles, with factory installed CC still working.

So why are some CC being spent/damaged, sooner rather than later. First and foremost; raw fuel entering them. How does this happen:
A) Over filled fuel tank.

1. Adding fuel, after auto shut-off of fueling pump handle. 2003-up OM, warns against this. Doing so can flood the CC.
2. Fueling on hot day, with cold fuel. Fuel heats to ambient temp, expanding in tank.
3. Engine & transmission running hotter than normal on hot days. Radiant heat from engine, CATs & transmission, asphalt along with high ambient temp. Heating fuel as it returns to tank and in tank, expanding fuel.

What to do:

1. First never overfill.
2. On hot days. Either don't fill up, to full. Or drive, after fueling to reduce fuel level. Giving room for expansion in tank.
3. Service coolant system is number one. In getting engine operating temp to normal. Making sure all 3 radiators free of debris (clean radiator fins). Clogged Radiator fins, cann't transfer heat efficiently away from coolant. These clogged fins, result in excessive operating temp of engine and transmission. W also need to, tune engine and flush transmission.

If a fuel boiling event, has happen. You can bet, CC damaged. If so, it needs replacing. But first, we must address why and correct. Or we risk, damaging another CC.

Do you know if people successfully opening the CC and refreshing the activated charcoal media?
I have heard of people doing this with charcoal for an aquarium.

 

[Live to Ski]

Do you know if people successfully opening the CC and refreshing the activated charcoal media?
I have heard of people doing this with charcoal for an aquarium.

there is an extensive thread on this. You will have to use the search function to dig it up.

 

[2001LC]

Do you know if people successfully opening the CC and refreshing the activated charcoal media?
I have heard of people doing this with charcoal for an aquarium.

I've not, I just use new OEM. But some in mud have. But IIRC, someone stated, it's not aquarium charcoal.