Smell of gas…

[Rolexus]

2005 Tahoe, 4WD: Been awhile since I’ve posted… recently drove home in a bad winter rain storm. Upon parking in garage, a noticeable gas door occurred. No ‘service engine’ warning, and no codes appeared using OBD (Sorry if I’m not using the correct vernacular). Gas tank was ~ 3/4 full.

Both of the AC Delco 214-1105 - Vapour Canister Purge Valve and 241-2149 Vapour Canister Vent Selonoid were replaced when code showed EVAP issue about 30 months ago. Also replaced the gas cap with AC Delco @ same time.

Didn’t drive it for a few days, but continued looking for possible gas leaks in and around tank, gas lines and under hood - found Nada - nothing, and made sure the gas cap was securely in place.

When the weather improved, took it for ~ 10 mile drive. The gas odour being emitted has disappeared (for now…).

if this problem re-occurs, does my one have any possible insight as to where I could specifically look for the source of the smell?

Read another post by StuckinMN, suggestions revolved around fuel pump mounting plate…

Any advice greatly appreciated. Thanks in advance.

 

[OR VietVet]

Could be from the mount plate rust out but where is the rig located and salt on the roads? May have a rusted line too. Set park brake and let it run at idle and get dirty and check the entire system. Remember, lots of times, when fuel leaks, it cleans the immediate area.

 

[Logan5]

I had a hard to find fuel odor for a while. When I eventually found it it was the fuel pump. On the hard line before it connects to the plastic line. Had rusted a pinhole. That fuel pump sits down lower than the surrounding parts of the tank, so fuel can pool there and you won't see it until it gets real bad and runs over the edge.

Something I noticed when that was happening was when I went to start the car, if I put the key in and turned it straight to start quickly, the car would immediately crank but not immediately start. But if I turned the key slowly and let it stop at accessory to power up the electrical it would then start immediately when I turned to the key to start.

What I think was going on is the fuel line is pressurized even when the car was off, so next time I went to start a pressurized line lets the truck start immediately. Since I found the leak the truck starts immediately. But when I had a pinhole and the car sat overnight the line pressure would bleed out, and the next start it would take a moment for the pump to build up that fuel pressure that lets the car start.

 

[Fless]

Gas or Flex Fuel? Different pumps and seals.

I replaced the fuel pump in my '04 a few years back and about a year later started smelling fumes after I pulled it in the garage. I typically run E85 so it was a very distinct odor. Turned out either the gasket was defective or we put a little wrinkle in it when we installed the pump. A new gasket fixed that.

Your pump has more of an o-ring gasket (unlike mine) so I wouldn't expect it to be the same. You may be able to view the pump and assess its condition through the left rear wheel well by removing the wheel liner and maybe another rubber splash. If you do get to the point of replacing the fuel pump, get a new fuel tank lock ring, just in case you need it.

Is there a lot of rust on the truck frame? Curious about the condition of the metal.

 

[Rolexus]

I had a hard to find fuel odor for a while. When I eventually found it it was the fuel pump. On the hard line before it connects to the plastic line. Had rusted a pinhole. That fuel pump sits down lower than the surrounding parts of the tank, so fuel can pool there and you won't see it until it gets real bad and runs over the edge.

Something I noticed when that was happening was when I went to start the car, if I put the key in and turned it straight to start quickly, the car would immediately crank but not immediately start. But if I turned the key slowly and let it stop at accessory to power up the electrical it would then start immediately when I turned to the key to start.

What I think was going on is the fuel line is pressurized even when the car was off, so next time I went to start a pressurized line lets the truck start immediately. Since I found the leak the truck starts immediately. But when I had a pinhole and the car sat overnight the line pressure would bleed out, and the next start it would take a moment for the pump to build up that fuel pressure that lets the car start.

Yea, sounds logical, although this vehicle has always started well - no fuel line pressure issues.

question for you… did you replace the fuel pump etc., on your own, or take it to a shop? I’m a pretty handy DIY’er but something like that I’d rather take it in to someone I trust, once I’m more certain the stink is caused at-or-near the fuel pump locale.

thanks for your observations! Dwayne

 

[Rolexus]

Could be from the mount plate rust out but where is the rig located and salt on the roads? May have a rusted line too. Set park brake and let it run at idle and get dirty and check the entire system. Remember, lots of times, when fuel leaks, it cleans the immediate area.

Hi OR VietVet! its always parked inside garage. Live in Vancouver, so salt use on roads is minimal at best. I really like your suggestion of park brake/idle and wait to see. Makes sense that it would be easier to see if it’s a live idling situation. As I said, I had a good look at the areas over a couple of days, but never while idling.

Will definitely try your suggestion! Thanks so much! Dwayne

 

[Rolexus]

Gas or Flex Fuel? Different pumps and seals.

I replaced the fuel pump in my '04 a few years back and about a year later started smelling fumes after I pulled it in the garage. I typically run E85 so it was a very distinct odor. Turned out either the gasket was defective or we put a little wrinkle in it when we installed the pump. A new gasket fixed that.

Your pump has more of an o-ring gasket (unlike mine) so I wouldn't expect it to be the same. You may be able to view the pump and assess its condition through the left rear wheel well by removing the wheel liner and maybe another rubber splash. If you do get to the point of replacing the fuel pump, get a new fuel tank lock ring, just in case you need it.

Is there a lot of rust on the truck frame? Curious about the condition of the metal.

It’s gas on this 05. Got an excellent tip from MO VietVet about checking for leaks while it’s static and idling. I also like your suggestion about pulling the left rear wheel to examine the pump.

Even though this vehicle is currently in Vancouver and very limited salt use up here, previous owner did a lot of skiing, so commute to and from was on heavily salted roads - so some rust on frame… . I’ll be checking the entire fuel line route to see if any need replacing. Thanks for your suggestions! Cheers, Dwayne

 

[MassHoe04]

Of course visual inspection will be easy and cost nothing.
If you have a Tech 2 or bi-directional scan tool, you could also see if the fuel tank is holding pressure.
If unable to maintain pressure when commanded, you may have a leak in the top of the fuel pump, the gasket, filler or vent tubes.

Does it smell when you fill up?
I had a Ford Ranger. The fuel pump assembly had a steel plate on top. Rusted out. That was the extreme, but I found out when I filled the tank to the top and fuel poured onto the ground.

 

[Rolexus]

No smell when I fill, and I try to top it up beyond the click-stop by a few $, usually another 2-4 litres (CDN, eh? ). I’ll try your suggestion as well

 

[OR VietVet]

No smell when I fill, and I try to top it up beyond the click-stop by a few $, usually another 2-4 litres (CDN, eh? ). I’ll try your suggestion as well

If I was you, I would stop trying to "overfill" when getting fuel. That is gonna catch up to you and your evap system soon, if not already happening.

 

[Rolexus]

Yea, makes sense.

 

[Logan5]

Yea, sounds logical, although this vehicle has always started well - no fuel line pressure issues.

question for you… did you replace the fuel pump etc., on your own, or take it to a shop? I’m a pretty handy DIY’er but something like that I’d rather take it in to someone I trust, once I’m more certain the stink is caused at-or-near the fuel pump locale.

thanks for your observations! Dwayne

I did it myself. It's feels more daunting than it is. I watched a couple videos of someone dropping the tank and then went and did it. Honestly wasn't too hard. Once out replacing the pump is not hard.

 

[Rolexus]

Thanks Logan5, I might just try doing it myself. I had a 2001 Safari that needed a new fuel pump installed a few years back. The bill was ~$1,000 CDN - ouch! So if you say it can be done easily, I’ll pursue that. Cheers!

 

[Rolexus]

I did it myself. It's feels more daunting than it is. I watched a couple videos of someone dropping the tank and then went and did it. Honestly wasn't too hard. Once out replacing the pump is not hard.

hi again Logan5, some questions about dropping the tank - before dropping the tank, did you siphon off some gas first? Or did you just run the tank low? I’m definitely wanting to do this the safest way possible.

 

[Rocket Man]

hi again Logan5, some questions about dropping the tank - before dropping the tank, did you siphon off some gas first? Or did you just run the tank low? I’m definitely wanting to do this the safest way possible.

I have dropped two tanks. Both times I removed the filler nozzle and used that opening to stick a short length of garden hose into the tank, siphoned the gas into containers and poured it into my other vehicles. Once the fuel is out, the tank is easy for one person to handle. I used a piece of wood on top of a floor jack to lower it down. The bolts for the straps that hold it in place sometimes rust out along with the nuts/ clips so you should have new ones on hand. The evap lines and fuel lines have clips that can be a PIA but be patient and you’ll get it.

 

[Logan5]

I have dropped two tanks. Both times I removed the filler nozzle and used that opening to stick a short length of garden hose into the tank, siphoned the gas into containers and poured it into my other vehicles. Once the fuel is out, the tank is easy for one person to handle. I used a piece of wood on top of a floor jack to lower it down. The bolts for the straps that hold it in place sometimes rust out along with the nuts/ clips so you should have new ones on hand. The evap lines and fuel lines have clips that can be a PIA but be patient and you’ll get it.

This is the way.

Also drop the spare tire to give yourself more room. And you can get a little siphon pump very cheap.

 

[Rolexus]

I have dropped two tanks. Both times I removed the filler nozzle and used that opening to stick a short length of garden hose into the tank, siphoned the gas into containers and poured it into my other vehicles. Once the fuel is out, the tank is easy for one person to handle. I used a piece of wood on top of a floor jack to lower it down. The bolts for the straps that hold it in place sometimes rust out along with the nuts/ clips so you should have new ones on hand. The evap lines and fuel lines have clips that can be a PIA but be patient and you’ll get it.

This is the way.

Also drop the spare tire to give yourself more room. And you can get a little siphon pump very cheap.

Good additional advice, thanks! I already have a siphon pump, but the spare tire makes a lot of sense. Cheers, Dwayne

 

[MassHoe04]

Hopefully you are one of the lucky folks, who can get your spare tire down with no complication.

Mine has the safety catch rusted. I can get the cable to spool all the way down, but I haven't been able to get the safety released to drop the spare...

 

[Rolexus]

Ouch! … but mine is okay - I took someone’s steel garbage into a brand new Nokian winter tire a few months ago while on the highway. Found out the hard way how to change a tire in a winter storm with no shoulder to work on, while on a busy 2 lane rural highway.
The spare tire system worked well. I’ve changed a few over the years, just not on the Tahoe

 

[MassHoe04]

Ouch! … but mine is okay - I took someone’s steel garbage into a brand new Nokian winter tire a few months ago while on the highway. Found out the hard way how to change a tire in a winter storm with no shoulder to work on, while on a busy 2 lane rural highway.
The spare tire system worked well. I’ve changed a few over the years, just not on the Tahoe

WHile it is out, might be a good time to lube the heck out of the cable and mechanism. Silicone lubricants seem to dry out quick. I would probably use white lithium spray on it, if it were mine.