Slow fuel fill because of a bad tank?

[hawgfanman]

Hey guys, my 2011 Avalanche has the typical problem of only being able to trickle gas in to the tank. I dropped it off at the mechanic yesterday and he just called to tell me that I need to replace the fuel tank because there are baffles and check valves in the tank that have gone bad. He said that he disconnected all of the evap hoses and still could only trickle gas in. This was not what I expected to hear from him, I figured it was going to be the normal fix of the charcoal canister and related items. Have any of you guys ever heard of the gas tank itself being bad before? He says that the tank is discontinued by GM so I'm at a loss of what to do right now besides trying to find a used tank.

 

[Joseph Garcia]

I cannot personally assist you with your issue, but other members of this Forum much more knowledgeable than me in this area will chime in.

 

[blackelky]

Charcoal canister. 9/10

 

[hawgfanman]

Even without any codes set? He even told me that he disconnected all of the evap lines and he could only trickle it in.

 

[strutaeng]

I thought the culprit for this was the vent solenoid? Maybe it stuck closed? You can test it by powering battery power to it.

I had this same issue on my old OBS. Strangely on the that one the purge solenoid replacement fixed it. Technically the purge only opens once commanded by the ECU to burn off gasses stored in the charcoal canister.

 

[B-train]

I would maybe get a second opinion. It sounds like you either have a purge valve stuck closed, or the charcoal canister took a dump and plugged lines with pellets.

Also, as far as I know there aren't baffles in the tank. There's a baffled/protected area around the pump to keep a steady volume by it. Maybe others know more, but that's what I remember. The only time I've ever replaced a tank was because it rusted out - they don't just fail.

Drop the tank, pull the lines and pump. Have a look-see and I'm sure you'll find it pretty quickly

 

[hawgfanman]

I just wanted to update everyone on this. I finally got it to a different mechanic and he blew out all of the lines and that fixed the problem. He said he expected it to be the charcoal canister but when he pulled the lines from it, no pellets came out. He suspected that it had been replaced but whoever did it, just didn't clear the lines. It makes me mad the original mechanic obviously lied about disconnecting all of the lines and still not being able to put any gas in. At least now I know a mechanic that I can trust to actually diagnose the problem.

 

[B-train]

Glad you found the problem. The older I get, the more "wanna-be's" I see in the trades, especially auto mechanics. It's hard to find someone who has a work ethic that involves critical thinking, honesty, and a good base knowledge. There are a lot of half-assed dopes out there who probably couldn't find their way out of a wet paper bag....