2007 GMC 1500 Fuel Smell

[TJMaine]

2007 GMC Sierra 1500 CC with 190k miles on her

I did search around the forums and didnt find anything really pertaining to this specific issue.
My first guess/instinct was fuel line ( but there is never any spots under the truck after being parked and sitting )

Over the last few days I have noticed a gas smell coming from the truck ( not super strong, but enough to alert me )

Seems to be more prevalent at the rear of the truck on the opposite side of the fuel tank. ( near bumper, figured the fumes were accumulating under the bumper or something )
No gas smell under the hood at all

I rolled around under the truck today wiped my hand on anything that could have fuel on it ( and some that couldnt have ) with no fuel smell on my hand.

I live in a colder climate and has been warm lately ( figured some vent or something from fuel tank or something )

I dont notice it any more or less when the tank is full or empty

 

No difference if it's been sitting or recently driven.

 

I checked the exhaust for a strong gas smell ( nothing )

Any ideas? Foggy? Educated or even SWAG ( Scientific Wild A$$ guess ) are appreciated.

[newdude]

Salt where you are? Try and get a view of the top where the sending unit is mounted. Unfortunately we've seen a streak of rotted senders lately on 2007-2009 trucks.

[TJMaine]

Maine, we use all kinds of salt. I'll see what I can do tonight, hopefully I can do it without taking the bed off ( that would be a few weeks before I could do that )

You talking about the fuel level sending unit or the fuel pump?

http://www.gmpartscenter.net/auto-parts/2007/gmc/sierra-1500/sle-trim/5-3l-v8-gas-engine/fuel-system-cat/fuel-system-components-scat/?part_number=15808917

[newdude]

Number 6 in the picture. Pump. The top rots away.

[ifixedit]

By chance do you have a fuel filter which should be mounted inline along the inside of the frame (usually under the door on drivers side) that has gotten rusty and has perhaps sprung a small leak? Here in MN we also deal with lots of salt and had this exact problem, leaked very slowly and other than the gas odor was very hard to detect at first.

 

Run your hands along the inside bottom of the frame looking for fuel, won't be hard to find.

[TJMaine]

By chance do you have a fuel filter which should be mounted inline along the inside of the frame (usually under the door on drivers side) that has gotten rusty and has perhaps sprung a small leak? Here in MN we also deal with lots of salt and had this exact problem, leaked very slowly and other than the gas odor was very hard to detect at first.

 

Run your hands along the inside bottom of the frame looking for fuel, won't be hard to find.

I'll take a look tonight and see whats what, my guess with as many miles as my truck has it's something like this, the fuel pump ( sending unit ) or a fuel line

 

Which reminds me, why is it so hard to find fuel lines for this truck? I dont see a part number anywhere for it, ebay all they have is generic metal tubing kits... nothing pre bent with fittings on it.

Number 6 in the picture. Pump. The top rots away.

I'll be looking at this tonight as well. Thanks for the info guys!!!

[ifixedit]

My truck is a few years older than yours and has seen its fair share of salt as well. The fuel lines on mine are still in decent shape but the leak actually started at the fitting end of the filter due to the fitting itself getting pretty rusty, the filter was about 2 years old and was due for replacement anyways. I replaced the filter and all is fine now, but the fittings on each end can be a bit troublesome and will leak again if the threads aren't good and clean.

 

As far as finding fuel lines or why they're hard to come by I have no idea, I suppose GM figures they will last forever, just like the brake lines! Ya, sure, you bethca!

[TJMaine]

My truck is a few years older than yours and has seen its fair share of salt as well. The fuel lines on mine are still in decent shape but the leak actually started at the fitting end of the filter due to the fitting itself getting pretty rusty, the filter was about 2 years old and due for replacement anyways. I replaced the filter and all is fine now, but the fittings on each end can be a bit troublesome and will leak again if the threads aren't good and clean.

 

As far as finding fuel lines or why they're hard to come by I have no idea, I suppose GM figures they will last forever, just like the brake lines! Ya, sure, you bethca!

If it turns out it's a fuel line i'll have to call NAPA or GM dealer for some prices... Thanks for the info. Never disappointed when I come here for answers.

[Jsdirt]

Just FYI, I believe this newer generation of trucks has no external filter. Don't recall seeing one on mine ...

 

If it were mine, I'd just replace the affected section with F.I. hose, and double-clamp it to a salvageable section. MUCH cheaper and easier than scrapping the entire line.

[TJMaine]

Just FYI, I believe this newer generation of trucks has no external filter. Don't recall seeing one on mine ...

 

If it were mine, I'd just replace the affected section with F.I. hose, and double-clamp it to a salvageable section. MUCH cheaper and easier than scrapping the entire line.

I take this thing off road twice a month for a weekend from April-November. I dont want to be left 10 miles in the woods with a busted fuel line.... But at the same time i dont want to spend 800$ on a fuel line job. We'll see what I find, was way to damn cold last night to roll around under the truck ( 15 degrees ) and I had to dress up for work this morning. I'll have to look tonight

[Jsdirt]

If you run the hose inside the frame rail like the OEM, the danger of snagging it is pretty low.

 

Just make sure it's 30R9 rated. It's burst and working pressures far exceed what the pump can produce.

[TJMaine]

If you run the hose inside the frame rail like the OEM, the danger of snagging it is pretty low.

 

Just make sure it's 30R9 rated. It's burst and working pressures far exceed what the pump can produce.

Roger Dodger... yeah the road is a dirt road, then a logging road, then a ATV trail, then a walking trail the last 200 ft or so LOL.

 

Ruts, rocks, sticks mud... GOOD TIMES!

[ifixedit]

If it turns out to be a bad section of the original fuel line and you're worried about using rubber fuel line, you could replace the bad section with the correct size steel tubing again and just use short pieces of good reinforced rubber fuel line on each end with clamps to splice in the new piece. As long as the line is secure on the frame and isn't out in the open flopping around it ought to work just fine.

 

Do you have a small pipe cutter like the plumbers use? If not they're available at most any hardware or home improvement store.

[TJMaine]

Well it stopped for a day, then today my co worker noticed he smelled gas near my truck, nothing dripping ( entire underneath of truck is clean and dry ) but seems to be accumulating in the wheel well and under the rear bumper. my guess is the top of the fuel tank where the fuel pump is is leaking or is rusted out. Unless i end up with fuel on the ground I wont be doing anything with it this winter. Early spring I'll try and pull the bed off I guess and see whats what.

I also had a revelation as far as taking the tank out... disconnect all the hoses and shit, loosen straps, lower truck ( I have a family member who has a lift ) put a jack or jack stands under fuel tank, remove straps, raise truck on lift to lift it off fuel tank ( i dont have a jack tall enough to reach fuel tank on the lift ) and see whats going on under there... PITA

GM guys, is there an easy way to get to the top of the gas tank under the truck with a camera/ cell phone? Just curious if there is an easy access area or something.

[TJMaine]

Got a check engine light today. Was p0452 Which led me here

http://engine-codes.com/p0452_gmc.html

 

But the fuel smell worries me. Is this because the sensor is messed up or am I looking at a compilation of issues.