Fuel odor vapor canister issue 2005 suburban

chevrolet
suburban

#1

Hi folks. I’ve got a 2005 suburban and as the colder weather has arrived I get a strong odor of fuel around the rear of the vehicle. However, only when the vehicle is running. If it sits off for a while, there’s no more odor. I’ve checked for leaks and can find no sign of them on the ground when parked and no breaches in the tank or hoses. Along with the fuel odor, I have the difficulty fueling with the gas pump triggered to stop. I’ve just now replaced the purge solenoid because I read that helps with that issue. My questions are these…

Could it be that the purge solenoid was the cause of my fuel odor? I don’t have any check engine lights or errors. The vehicle did idle rough a couple times long ago, but I stopped it and restarted those times and it stopped, and hasn’t done it again for around a year. Lately the car did seem to struggle to start a couple times.

Also, I cannot run the blower for heat when the car is idle. I get so much exhaust and fuel odor in the cabin if I do. When moving I get none but if idle at a stop it has to be turned off. Could this be coming from the odor in the rear of the car? I have idled the car with the hood up and checked the fuel rail for leaks but I could find none. Am I wrong to assume it’s just being sucked in because there’s no breeze when I’m at idle and it’s not an issue around the engine? There’s no change in the sound of the exhaust system to suggest a leak in that system.

Lastly, I might as well change the vapor canister as well. The bolts are just mounds of rust so they won’t be any use when I take the bracket off. Does anyone know what size these are so I can purchase them before I start changing out that part? I can’t find that info anywhere. Could the vapor canister be the cause of my odor? Again, no error codes or anything.

Thanks for your help, it’s greatly appreciated.


#2

Have you actually dropped the fuel tank to see if the quick-connect fuel line is leaking?

Because it takes very little gasoline to create that smell.

Tester


#3

This is only a wild guess, but fuel leaks of the injector “O-rings” is not at all uncommon on older GMs.


#4

No I have not dropped the tank and I do understand it’s entirely possible to have a leak at the top of it. I’m trying to eliminate the easiest stuff for me to take care of first.

Thanks, I will check the o rings for a leak. If it was just the fuel I smelled in the cabin I would lean to a leak in the engine compartment somewhere but since it’s fuel and exhaust it makes me think it’s just coming from the rear of the car.


#5

I’m thinking that the EVAP pressure test doesn’t detect a leak because it’s so small.

But when the fuel pump turns on, that pressure creates a gas mist?

Seen it!

Tester


#6

I expect you already know OP that there’s quite a few things that could cause this. Fuel lines, vent lines, connectors, numerous valves, canister, etc all involved with fuel delivery and all can develop leaks or other faults. Good ideas to check above. I’ll add that one time I had a similar symptom w/my truck, smelling gasoline at the rear only when the engine was running, and that turned out to be the idle air/fuel mixture was too rich. The gasoline smell was coming from excess gasoline making its way into and out the exhaust pipe. Which explains why I only noticed it when the engine was running. In my truck’s case it was a problematic carburetor causing the problem. If you do in fact have a rich mixture condition causing this, that would usually turn on the check engine light and post a rich code. Anything like that happened recently?


#7

May be the evap canister is leaking. I remember my buddy had the same problem, and the canister was the culprit.


#8

OK so I changed the solenoid and the problem remained. Today after exiting the car in a wet parking lot I saw rainbows on the pavement following the path of my car. I looked underneath and and there was no visible leak. I went home, put the car up on ramps and got underneath…fuel pouring out from the middle of the tank. It’s coming from the top and running down the side but now I cannot figure out if it’s from a line that runs across the top or if its from a breach in the tank itself.

The car takes a long time for the engine to catch when it’s not been started for some time. The leak only happens when the car is running and stops completely a few minutes after the engine has been stopped. Should I take these signs to mean the leak is in the actual line and not the tank?

Thanks again for everyone’s input.


#9

It’s a fuel line leak.

Because if it were a tank leak, the tank would leak when it’s filled, and then stop leaking as the fuel level dropped.

In your case, the leak only occurs when the fuel pump is operating.

And the fuel line will continue to leak after the engine is shut off until the residual fuel pressure bleeds off.

Tester


#10

It’s entirely possible this is related to the leak. Suggest to fix the leak, and hopefully that will fix the slow to start problem too. This is the kind of problem where it is usually better to have a good, experienced shop do the work btw. If you decide to tackle any gasoline related diy work yourself, be sure to research the necessary safety precautions involved.


#11

Just updating the issue in case it helps anyone else with similar symptoms. I dropped my fuel tank to get a closer look at what might be the problem. Upon doing so it was clear as day, the fuel pump was rotted out. The fuel pump sits in a recess in the tank which I imagine water and salt from winter pools. One of the lines at the elbow out of the pump had a hole rusted through it the size of a BB pellet. I barely touched those lines and they snapped off inside the fittings. I spent a good 1.5 hours desperately trying to pull the rusted metal out of the ends so that I could connect a new pump before finding out that they make repair end kits. Once I found that out I cut off the old ends, installed the new ones and put in a new pump. The problem has been resolved.

I also had to cut away the rubber hose connecting the fill tube to the fuel tank with a razor. Even with unbolting the fill tube there was simply not enough play to pull the hose off the fuel tank so I just had a new piece cut and installed that.

Thank everyone for their input.


#12

Good for you for sticking with it and ending that annoying fuel odor problem. One thing about automobiles, and you’ve proved it again with your post, there’s no end to the ways which vehicle parts fail. Thanks for posting the update, good to know the final result.