Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen? (3 Viewers)
- Thread starter 2001LC
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What year is your truck? Im having same issue as well 06LX 135k miles
Bumping to confirm in my 02 just replacing the charcoal canister with new OEM, recent TB so new coolant, new radiator, new thermostat, new fuel filter did not prevent over pressure and boiling on recent trip to Alpine Loop. I opened the gas cap at the Animas ghost town and it eventually boiled out the side of my vehicle. Scared the hell out of some bystanders.
Guess I'll wrap the lines next and try some reflective tape or something on the tank.
Operating temp never went over 190-195 range. Outside temps were in the 70s when it happened so not a hot day either.
Ethanol fuel was a scam and I hate it, also.
Guess I'll wrap the lines next and try some reflective tape or something on the tank.
Operating temp never went over 190-195 range. Outside temps were in the 70s when it happened so not a hot day either.
Ethanol fuel was a scam and I hate it, also.
If the small gas station in the middle of Silverton still sells ethanol free, that is an easy solution that works for me and my friends. No issues even at the top of Imogene Pass.
on my 80 I found my VCV was bad, thus not applying proper vacuum to the evap system. I replumbed the vac lines and vcvs out from under the plenum . tried new CCs, no change, non ethanol helped a little, but not entirely. I also added a fuel cooler, not much change. I also put a "y" with a 1 way flow valve in the bottom CC hose and vented that straight to atmosphere , the other runs into the blue 5 way vacuum switch thing . this allows the vac system to suck the fumes when running, and any emit can't suck in gets pushed through to atmosphere. I know sounds weird, but I have not had a pressured tank since. If anyone wants more details I'm happy to share.
I had already replaced the vcv on mine but didn't resolve the issue. Just today replaced the charcoal canister so we'll see if my over pressure situation improves. Saw somewhere on mud that one guy replaces the fuel pressure regulator on the rail and the fuel damper. That will be next thing to try if problem isn't resolved.
My LC also runs a little hotter than I would like in warm weather. Typically 191 is the base on warm days and under load easily gets to 200. Big tires and no regear I'm sure contributes. Have a new radiator so that shouldn't be the issue.
But I'm not sure if we have a fuel problem that leads to high temp, or a high temp issue that leads to hot fuel.
My LC also runs a little hotter than I would like in warm weather. Typically 191 is the base on warm days and under load easily gets to 200. Big tires and no regear I'm sure contributes. Have a new radiator so that shouldn't be the issue.
But I'm not sure if we have a fuel problem that leads to high temp, or a high temp issue that leads to hot fuel.
2001LC
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At 70F OAT. Seeing 195 ECT, something not right!
2002 will run all day long: stop and go, 130F black top, both AC full, 101F OAT. ECT 184 to 187F. with hitting 190F max, for only moments.
If you've full under armor,bell pans creating a heart tunnel. Then for sure shield and defect hot air.
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What would you expect for an '03? Same?
But does this remain true when a vehicle starts climbing up and up and up, working everything a lot harder, under more of a load than a vehicle being tested around city style driving.
Can a healthy 2UZ really hold temps under 190F even on the hottest days when climbing hard?
2001LC
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Keep in mind, some fuel tank pressure and hiss as cap cap removed, is normal and noted in Owners Manual.
Some will say all 100 series boil fuel. It is just not ture. Non run hot or boil fuel in my part of the world, they day they come from factory. I suspect is the same, anywhere in the world.
I've only full days on and off road, ECT & FT data, on 00-02 & 06-07 in pure stock. I have run data on built rigs, but only around town City/HWY and mtn HWY not off road and not all day.
The 00-02 run the coolest. I suspect 98-00 w/condensor fan, to run the same ECT. Mtn off road to tree line, HWY & City, July 1 full sun sun 101F. 6 hours driving with one lunch break. AC full front and rear. HWY stop and go was highest ECT at 3PM sun, where speed 0 to 35MPH at end of 90 minutes HWY. hitting 190f at 0MPH for moments. Most of 6 hours ~187f. HWY stop and go on hot black radiant heat is very demanding!
The 06-07 (note: 06-07 have different fan clutch and fan). I suspect 03-05, run about the same ECT. ECT runs 184-187 32f-68f. Then as OAT jumps so does ECT, running at 194-197F. These jump up ~3f degrees momentarily at stops in w/ OAT ~68f w/both AC on full.
This summer, time permitting, I'll run logs on my 03.
I've so many come to me running hot. They think all is well, which I find not the case. We correct all, starting with the 3 radiators fins. We must clean all three's rads fins, not just R&R the engine radiator. We also make sure good OEM thermostat installed properly, good OEM Rad. Cap and proper working expansion tank. No air in coolant system. AT fluid must have good, which in 98-02 is Mobil I, which runs the coolest. I'll note: Some AT arent in great condition, their fluid temp jumps up fast. Those transmission run hot, which its rad being first to catch air. Dissipates excessive hot air to the other two rads as does it transmission body radiates more heat). Gear lube in good condition, which I use Mobil 1 75w-90. Once everything as it should, like the day it came from the factory. Which includes fuel trims leaks and good compression. If engine running poorly or ECT running hot, we then look at EVAP side which includes proper funktion from gas cap to VSV at intake manifold. Charcoal Canister ( CC) are last piece of puzzle.
The 98-02 CC is NLA (No Longer Available For Purchase). I've yet to replace a CC, on any 98-02. Or find issues with them. I know substitute CC are being used. I've no idea if these sub CC, have what we need to properly vent all vapor.
With the 03-07, I've replace a fare number of CC (06-07 pre filter also). In fact, I just R&R one on a 24K miles 07LC. These CC get flooded, very easily. Just fill gas tank, squeezing pump handle one extra time, fill with front of vehicle point on the down hill, fill on hot day and not driving right away (parking), filling and climbing a hill especially on a rocky road. Anything that cause fuel to travel up fuel fill tube, can flood the CC with raw fuel.
Even built rigs I've drop ECT. But built have add weight. Also added mass in engine compartment & iron bumper & winch that retains heat and blocks air flow. If fully armored, the are the worst. They trap hot exhaust, engine and AT air, in a tunnel fuel lines run in and tunnel hot air onto fuel tank. Here's where use radiant heat deflectors and air deflectors/diverts can be of a greastedt benefit.
The 100 series 4.7L 2UZ, is well suited for; low RPM high torque (clawing around off-road) in stock configuration. Modified it a different animal.
Some will say all 100 series boil fuel. It is just not ture. Non run hot or boil fuel in my part of the world, they day they come from factory. I suspect is the same, anywhere in the world.
I've only full days on and off road, ECT & FT data, on 00-02 & 06-07 in pure stock. I have run data on built rigs, but only around town City/HWY and mtn HWY not off road and not all day.
The 00-02 run the coolest. I suspect 98-00 w/condensor fan, to run the same ECT. Mtn off road to tree line, HWY & City, July 1 full sun sun 101F. 6 hours driving with one lunch break. AC full front and rear. HWY stop and go was highest ECT at 3PM sun, where speed 0 to 35MPH at end of 90 minutes HWY. hitting 190f at 0MPH for moments. Most of 6 hours ~187f. HWY stop and go on hot black radiant heat is very demanding!
The 06-07 (note: 06-07 have different fan clutch and fan). I suspect 03-05, run about the same ECT. ECT runs 184-187 32f-68f. Then as OAT jumps so does ECT, running at 194-197F. These jump up ~3f degrees momentarily at stops in w/ OAT ~68f w/both AC on full.
This summer, time permitting, I'll run logs on my 03.
I've so many come to me running hot. They think all is well, which I find not the case. We correct all, starting with the 3 radiators fins. We must clean all three's rads fins, not just R&R the engine radiator. We also make sure good OEM thermostat installed properly, good OEM Rad. Cap and proper working expansion tank. No air in coolant system. AT fluid must have good, which in 98-02 is Mobil I, which runs the coolest. I'll note: Some AT arent in great condition, their fluid temp jumps up fast. Those transmission run hot, which its rad being first to catch air. Dissipates excessive hot air to the other two rads as does it transmission body radiates more heat). Gear lube in good condition, which I use Mobil 1 75w-90. Once everything as it should, like the day it came from the factory. Which includes fuel trims leaks and good compression. If engine running poorly or ECT running hot, we then look at EVAP side which includes proper funktion from gas cap to VSV at intake manifold. Charcoal Canister ( CC) are last piece of puzzle.
The 98-02 CC is NLA (No Longer Available For Purchase). I've yet to replace a CC, on any 98-02. Or find issues with them. I know substitute CC are being used. I've no idea if these sub CC, have what we need to properly vent all vapor.
With the 03-07, I've replace a fare number of CC (06-07 pre filter also). In fact, I just R&R one on a 24K miles 07LC. These CC get flooded, very easily. Just fill gas tank, squeezing pump handle one extra time, fill with front of vehicle point on the down hill, fill on hot day and not driving right away (parking), filling and climbing a hill especially on a rocky road. Anything that cause fuel to travel up fuel fill tube, can flood the CC with raw fuel.
Even built rigs I've drop ECT. But built have add weight. Also added mass in engine compartment & iron bumper & winch that retains heat and blocks air flow. If fully armored, the are the worst. They trap hot exhaust, engine and AT air, in a tunnel fuel lines run in and tunnel hot air onto fuel tank. Here's where use radiant heat deflectors and air deflectors/diverts can be of a greastedt benefit.
The 100 series 4.7L 2UZ, is well suited for; low RPM high torque (clawing around off-road) in stock configuration. Modified it a different animal.
a most excellent synopsis
So I guess here's my annual post in this thread where I come to complain about my favorite vehicle that I love to love, and also love to hate.
Yesterday I used my (mostly) bonestock '05 LX470 to pull a u-haul trailer from Omaha to Arvada. Was a relatively light load.
I was on the road at 7am. Coolant temp was ~190 most of the morning and into the noon hour. Pretty normal stuff even without the trailer.
As I got closer to Denver around 1pm local time, temps were averaging ~203. I saw 205 a couple brief moments. Definitely the hottest I've ever seen it. Don't think I've ever seen it hit 200 before.
It was hot out, no doubt. Phone said low 90s. Dashboard board said 95.
When I finally got to my destination and got out of the LX, I could smell gas while out in the driveway. Opened the gas cap to vent it and there was a LOT more than the normal hiss. Pressure was really high. It took probably a half hour (at least) before I wasn't smelling gas while standing in the driveway any longer.
The silver lining is it never smelled inside the cabin while driving, and no gas boiled out in my new-to-me driveway.
Do 200s have this problem?
Yesterday I used my (mostly) bonestock '05 LX470 to pull a u-haul trailer from Omaha to Arvada. Was a relatively light load.
I was on the road at 7am. Coolant temp was ~190 most of the morning and into the noon hour. Pretty normal stuff even without the trailer.
As I got closer to Denver around 1pm local time, temps were averaging ~203. I saw 205 a couple brief moments. Definitely the hottest I've ever seen it. Don't think I've ever seen it hit 200 before.
It was hot out, no doubt. Phone said low 90s. Dashboard board said 95.
When I finally got to my destination and got out of the LX, I could smell gas while out in the driveway. Opened the gas cap to vent it and there was a LOT more than the normal hiss. Pressure was really high. It took probably a half hour (at least) before I wasn't smelling gas while standing in the driveway any longer.
The silver lining is it never smelled inside the cabin while driving, and no gas boiled out in my new-to-me driveway.
Do 200s have this problem?
Well this is the second 100 that we've experienced the problem in. The first one was an '03 LC (seen my thumbnail) that had lived a hard life previous to our ownership, and it just plain old ran hot despite all the work we'd put into it... particularly the fuel system... which is detailed somewhere in this thread. Regardless, my wife ultimately solved the problem by trading the thing in for a brand new Rav4 late last year.
My LX470 is pretty much the opposite story... it lived a life of privilege previous to my ownership, and I've kept that tradition up these past couple years. It does not run hot. It is pretty well sorted. The only notable mod is one LRA 40 gallon fuel tank, which was swapped from the aforementioned LC. I applied extensive heat shielding to it (documented in this thread). Admittedly last year when I experienced fuel smells it wound up being a faulty hose line that leaked, and not the inherent design flaw that leads to excessive pressure & fuel boil / smell.
Keep in mind I just drove from Omaha to Arvada... so those bugs you see in the radiator were picked up along the way. I tried best I could to get a photo between condenser and radiator.
2001LC
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So I see a few issues that may indicate clues, of improper service. Kind of typical stuff I see, daly. Possible I'm miss reading (seeing pictures wrong).
We must correct all issues starting with front end "radiator:, before we R&R CC. Or risk, taking out another CC.
Today we can't get 98-02 CC, as they are NLA. I know many have turned to alternate CC. But I've no idea if they work well as need in our 100 series. If EVAP not working as designed. We then very often build excessive gas tank pressure.
As far as long range fuel tanks. We'll personally; Anything not installed by factory, always raise a red flag.
- Battery negative post clamp, over tighten. It's a replacement aftermarket clamp, so likely factory was also overtighten. Not sometime that results in engine running hot. Just a clue as to wrencher experience.
- Brake fluid dark and appears over filled. Improper service.
- Radiator fins dirty, resulting in engine running hot. This (hot) will be most notable in slow speeds or at a stop light.
- Coolant expansion tank, appears empty. This can be a very big deal. Since coolant system will suck air, from expansion tank. It a sign system not properly bleed of air. These system tend to lose coolant, a much faster rate than normal. The engine will run hot the lower the coolant. Low coolant, also damages high point of coolant system, where air pocket gather. i.e. plastic of radiator top and heater Tees. The plastic drys out and prematurely falls.
- Aftermarket radiator, missing all foam. The foam, helps direct air through radiator. When missing and fin clogged, path of most resistance is though fins, and around radiator fins becomes path of least air resistance. Resulting in poor dissipation of heat. Hot running engine!
- Air filter seal curled. I find this in about 30% of 100 series. It just not being aware, of the need to be careful when placing air box cover on. In every case I've seen, seal curls downward. This allows, dusty air, to freely move into air intake (MAF sensor, T-body, valve steams, seats and cylinder walls). Sign of how much dusty can be seen, in mouth air of intake pipe. MAF is first concern. Bad or wonkey MAF, can take out CAT fast. Damages cylinders & rings is biggest concern.
- Anytime I see a gas cap area dirty/mucky. I replace Charcoal canister. This is especially true of the 03-07. Every one of those, CC weigh in heavey, compared to new. Which is clue of how saturated the CC is.
We must correct all issues starting with front end "radiator:, before we R&R CC. Or risk, taking out another CC.
Today we can't get 98-02 CC, as they are NLA. I know many have turned to alternate CC. But I've no idea if they work well as need in our 100 series. If EVAP not working as designed. We then very often build excessive gas tank pressure.
As far as long range fuel tanks. We'll personally; Anything not installed by factory, always raise a red flag.
@2001LC , I appreciate you taking the time to respond. I'm going to respond to some of the points just as a matter of setting the record straight, as I think the pictures may be misleading you.
Not trying to be argumentative, but I will say I don't think trying to ascertain "wrencher experience" advances the objective, or serves any purpose.
On a flat surface, the brake fluid is a hair or two over the full line. In this photo it's not on a flat surface... rather pointing downhill pretty good, so likely looks worse to you than it really is. Don't know what you mean by dark.
1. It doesn't run hot. This past trip is the only time I've ever seen coolant temp hit 200. Usually is in the 185-190 range.
2. A couple days before the trip, I actually used your "how to" thread to clean the fins. So they might not be fresh-out-the-box clean, but they should be relatively clean.
It's full of Toyota red.
I agree it's aftermarket and there's no OEM foam. However, lots of people running Denso radiators sans OEM foam.
Maybe I'm not seeing what you're seeing... but it looks pretty normal & clean to me. I believe the filter was replaced at last oil change just a few thousand miles ago.
I'm due for another oil change when I get back to Omaha. I'll ask my shop to see whether they think the CC worth doing it now or if they think some of these and/or other things should be looked at first.
Not trying to be argumentative, but I will say I don't think trying to ascertain "wrencher experience" advances the objective, or serves any purpose.
On a flat surface, the brake fluid is a hair or two over the full line. In this photo it's not on a flat surface... rather pointing downhill pretty good, so likely looks worse to you than it really is. Don't know what you mean by dark.
1. It doesn't run hot. This past trip is the only time I've ever seen coolant temp hit 200. Usually is in the 185-190 range.
2. A couple days before the trip, I actually used your "how to" thread to clean the fins. So they might not be fresh-out-the-box clean, but they should be relatively clean.
It's full of Toyota red.
I agree it's aftermarket and there's no OEM foam. However, lots of people running Denso radiators sans OEM foam.
Maybe I'm not seeing what you're seeing... but it looks pretty normal & clean to me. I believe the filter was replaced at last oil change just a few thousand miles ago.
I'm due for another oil change when I get back to Omaha. I'll ask my shop to see whether they think the CC worth doing it now or if they think some of these and/or other things should be looked at first.
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Just got back to Omaha. Return trip was sans U-Haul trailer... and also sans any irregular fuel tank pressure or gas smells. Coolant temp never got over 194... which only occurred during the 2pm hour when it was reading 93 degrees outside, and I was doing ~85mph. During this time it fluctuated a lot between 190, 192 & 194.
For most of the trip coolant temps were steady at 187... like eerily steady.
For most of the trip coolant temps were steady at 187... like eerily steady.
@2001LC Good point about the air filter. I found the same gasket curling on my rig but in the opposite corner.
I also had an Denso rad without the foam. I added 16465-50370 Toyota OEM Genuine PACKING, RADIATOR (from 200 series) to the top and some generic foam I had lying around to the sides.
I also had an Denso rad without the foam. I added 16465-50370 Toyota OEM Genuine PACKING, RADIATOR (from 200 series) to the top and some generic foam I had lying around to the sides.
Oh that makes sense now, thanks! Will see about dropping a new filter in there.
As for the foam, do you have any pics that could guide me as to how I could apply it?
