Getting message?:"Tighten Gas Cap" or are you Unable to fill your tank? ! Look here !
- Thread starter Anthony
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Dan Acosta
Full Access Member
- Joined
- Feb 26, 2017
- Posts
- 186
- Reaction score
- 41
Newbie here... Same/similar issues. I read through and I dont think I could find a solution. So I decided to take it from the top...
I have a 2005 Tahoe with horrible fuel filling issues. It does not show any codes.
I have replaced the evap valve - under the rear of the truck
I have replaced the charcoal cannister, it was bad, but apparently not the issue. (Had loose pellets)
I have verfified that the rollover valve is not stuck.
I have spliced a evap hose as it had a kink (not the problem)
So I am at a loss. I am trying to avoid the fuel tank drop, but that looks like it is my next step. I am just not sure what to look for, other than some clogs in lines?
ALso, the purge valve on the intake has not been changed, but it seems that is more related to evap codes rather than fuel fill-up issues. I could be wrong.
I REALLY need some help here! - Thanks Dan
I have a 2005 Tahoe with horrible fuel filling issues. It does not show any codes.
I have replaced the evap valve - under the rear of the truck
I have replaced the charcoal cannister, it was bad, but apparently not the issue. (Had loose pellets)
I have verfified that the rollover valve is not stuck.
I have spliced a evap hose as it had a kink (not the problem)
So I am at a loss. I am trying to avoid the fuel tank drop, but that looks like it is my next step. I am just not sure what to look for, other than some clogs in lines?
ALso, the purge valve on the intake has not been changed, but it seems that is more related to evap codes rather than fuel fill-up issues. I could be wrong.
I REALLY need some help here! - Thanks Dan
Dan Acosta
Full Access Member
- Joined
- Feb 26, 2017
- Posts
- 186
- Reaction score
- 41
SOLVED - Well, if anybody cares I found the issues. As I mentioned previously I had changed a few parts already and no luck. So I decided to drop the tank and check for a crimp or clog in the evap lines. I blew some air through the lines and out shot the small charcoal beads that were from the inside the charcoal cannister. Then I put some carb cleaner just to be sure and then replaced all of the hoses and tank. Now it fills like a dream.
Thanks for the update. I'll definitely help others[emoji106]
Sent from my iPhone using Tapatalk
73impala
Full Access Member
UGH wish i thought about trying this before! I've replaced the fuel pump and had the tank dropped. I'll give this a try. Do you know what hose it was? Or did you just follow the one coming off the canister?
ivin74
05 NBS Nali
There is 3 hoses that tie in together if im not mistaken, blow all them out. All my hoses had charcoal beads even my fuel tank. To keep this from happenning DO NOT TOP OFF YOUR TANK again, thats the best fix.
Last edited:
ugh i hope i dont have to drop the tank. i replaced the solenoid/valve already and have a charcoal canister coming in saturday that im going to replace. truck will be ready for a fill up after that so ill try it. if it doesnt fill up im gunna take it home and drop the damn tank lol.
73impala
Full Access Member
Honestly not a bad job to drop the tank. Jack it up some to be able to work under it loosen some of the hose clamps and then the tank straps and it'll slide down.
ivin74
05 NBS Nali
This issue has nothing to do with the carbon canister, that issue has to do with your fuel pump. My SUV stated doing the same thing everytime I would fuel it up and once I change the fuel pump it never did it again
Yea it wasn't bad. Just lowered it enough to get to the connections since it was a bit over half full. After the canister went on and didn't fix I lowered it. the canister was spilling the pellets everywhere so i figured it was probably booty in the lines too.
Blew them out with air and massive amounts of charcoal came out.
Filled it up no issue after but the pump was a bit slow. Going to drive it this week and burn the gas out and try again.
dropping the spare gives you so much room to work under the back of it. i had it on some drive up ramps and was just sitting under the rear working on everything. it was nice.
Last edited:
so we went to fill it up again on saturday and same problem with the pump clicking off.
learn from my mistake and dont think you can just disconnect a few lines while the tank is lowered without disconnecting everything. just take it all the way out the first time and clean the hoses.
wife and i did that sunday. dropped it out, blew out all the lines (and got a LOT of charcoal out again) until they were flowing substantial air out. reinstalled and it filled up like a dream.
what an annoying problem.
learn from my mistake and dont think you can just disconnect a few lines while the tank is lowered without disconnecting everything. just take it all the way out the first time and clean the hoses.
wife and i did that sunday. dropped it out, blew out all the lines (and got a LOT of charcoal out again) until they were flowing substantial air out. reinstalled and it filled up like a dream.
what an annoying problem.
I have an 05 Cadillac Escalade. First issue I noticed was the pump stopping and not being able to fill the gas tank. Next I had the check engine light come on. I then replaced the purge valve and the evap canister. The check engine light went off, but the filling problem continued. I then got an alert on the display panel to tighten the fuel cap. I changed the canister solenoid next and I'm still having the issue. I have not actually checked the gas cap itself yet. From what I've read, I thought the problem would be one of the parts I've replaced but I haven't had any luck yet. Help please!!
clandr1
Full Access Member
I've done the same thing as you with the same result at most pumps, however there are some pumps that I use that have no trouble filling up without clicking off. I've just chalked it up to a redesign in pumps over the last 13 years I've owned my truck.
shartymcqueef
TYF Newbie
- Joined
- Nov 24, 2021
- Posts
- 7
- Reaction score
- 5
For anyone looking for help with these problems in the future, this should help:
Hack job. Fix it right by diagnosing and using functional parts. It's a simple system and isn't all that tough to make work correctly.
As I posted in response to your other multiple posts of this, it's one cause among many. If the pellets have migrated into the evap lines, to the purge solenoid or the vent valve, you'll have more work to do.
shartymcqueef
TYF Newbie
- Joined
- Nov 24, 2021
- Posts
- 7
- Reaction score
- 5
Hack job? Lmao! This is GM asking people to waste money for no reason. It’s a GAS TANK VENT. Same concept as on your red can for the mower or any other gas tank!
GM wants to muddy the water so rubes will waste money to “do it right” when all you need is a clean and clear vent from the tank to the atmosphere.
Anyone saying otherwise… rube
ivin74
05 NBS Nali
It's not GM, it's the EPA that put those regulations in place. The carbon canister is there to kept the gas fumes from going to the atmosphere. If you delete the carbon from the canister, the vehicle will be smelling like gas all the time.
I did that to a ford Taurus and after about 2 days of smelling gas I purchase the canister and left the sht alone.
I realize this is an old yet ongoing thread. I thought I'd list my experience in case anyone runs across this.
Our 2005 Tahoe with roughly 160K (at the time) started having fuel filling issues. if you tried to lock the handle it would either shut off, or spill gas everywehere. We would sometimes get the "tighten gas cap" message as well. But sometimes it would go days and days without displaying that message. We also never once had a code. Just slow fill and occasional tighten gas cap message. So I replaced the solenoid...didn't work. Started researching, watching YT videos etc and found many people talking about vent lines and them becoming clogged with charcoal pellets which keeps the tank from releasing pressure as you fill. So I disconnected the line with the white clip going from the tank to the evap canister and sure enough, tons of pellets fell all over the floor. That's actually the only line I could get free, but I knew right away what the issue was. I tried hooking a shop vac to that line to suck out while someone up top opened and closed the gas cap to allow the fuel tank to expand and contract. This removed some pellets, but issue was still there. So, I was prepared to drop the tank, but then I found a guy in the comments of a YT video that said he didn't drop his tank at all. He simply disconnected the lines to the evap canister and stuck the tip of his leaf blower into the gas fill tube, and turned it on. He said pellets flew out all over the ground and issue was resolved. Reading that I decided to take a funnel, cut the end off to open the hole up a bit bigger (more velocity) and stuck it into the gas fill tube. Took my shop vac on exhaust side (cleaned it out of course) and blew into the funnel. Pellets came out everywhere. Went to get gas, filled up faster than it ever has. We still get an occasional "tighten gas cap" message, but the truck has been driven mayb an hour since I did all of this. Not sure if that'll go away after driving it more, like a code does. But this issue was resolved fairly easily with this method.
Our 2005 Tahoe with roughly 160K (at the time) started having fuel filling issues. if you tried to lock the handle it would either shut off, or spill gas everywehere. We would sometimes get the "tighten gas cap" message as well. But sometimes it would go days and days without displaying that message. We also never once had a code. Just slow fill and occasional tighten gas cap message. So I replaced the solenoid...didn't work. Started researching, watching YT videos etc and found many people talking about vent lines and them becoming clogged with charcoal pellets which keeps the tank from releasing pressure as you fill. So I disconnected the line with the white clip going from the tank to the evap canister and sure enough, tons of pellets fell all over the floor. That's actually the only line I could get free, but I knew right away what the issue was. I tried hooking a shop vac to that line to suck out while someone up top opened and closed the gas cap to allow the fuel tank to expand and contract. This removed some pellets, but issue was still there. So, I was prepared to drop the tank, but then I found a guy in the comments of a YT video that said he didn't drop his tank at all. He simply disconnected the lines to the evap canister and stuck the tip of his leaf blower into the gas fill tube, and turned it on. He said pellets flew out all over the ground and issue was resolved. Reading that I decided to take a funnel, cut the end off to open the hole up a bit bigger (more velocity) and stuck it into the gas fill tube. Took my shop vac on exhaust side (cleaned it out of course) and blew into the funnel. Pellets came out everywhere. Went to get gas, filled up faster than it ever has. We still get an occasional "tighten gas cap" message, but the truck has been driven mayb an hour since I did all of this. Not sure if that'll go away after driving it more, like a code does. But this issue was resolved fairly easily with this method.
Last edited:
