gas cap light issue...

[ram5.7hemi]

i have had a real problem with the gas cap message.. i have replaced the gas cap a couple times. took it into my mechanic and he ran a smoke test on it and it passed.. found a crack on the charcoal canister. he replaced that and reset everything. light stayed off for almost a week and came back on.. then ordered a new charcoal canister from a different company and reset every thing and it came back on again... this is driving me insane what could be causing this problem???

 

[LB3711]

check all the lines. I bet theres a bad one some where. I couldnt get rid of leak codes on my durango till I replaced all the lines.

 

[ram5.7hemi]

check all the lines. I bet theres a bad one some where. I couldnt get rid of leak codes on my durango till I replaced all the lines.

it passed the smoke test.. if a line was bad wouldn't the smoke test show that...?

 

[LB3711]

it should i guess

 

[JPT]

Does your tuck have that Star Trek space ship looking thing under the bed on the inside of the drivers side frame rail? If so, that is another possibility. Mine went bad, got a replacement part at autozone and swapped it in. I don't remember what it is called. I'm sure someone else will be able to name it.

 

[ram5.7hemi]

Does your tuck have that Star Trek space ship looking thing under the bed on the inside of the drivers side frame rail? If so, that is another possibility. Mine went bad, got a replacement part at autozone and swapped it in. I don't remember what it is called. I'm sure someone else will be able to name it.

i think you are referring to the charcoal canister. i had that replaced because it was cracked. my gas cap i replaced was from auto zone.. maybe i need to get an em one from the dealer. might try that tomorrow.

 

[crazy_luck]

Is the filler neck opening that the cap seals against metal or is it plastic coated? If it's metal and has rust on it, that might be your leak (which might not show on a smoke test). Take some wheel bearing grease and smear it on the rim of the filler tube and put the cap back on (clear the CEL if you can) and see if it comes back on.

Had to do that on my '01 1500 every 2~3 months to keep a seal. Also have a coworker with a '00 Bonneville SSEI that needs to coat his entire filler tube with grease every couple of months to keep it from venting and causing a CEL (a $5 can of grease goes a long way and is a lot cheaper than a $900 fuel tank).

 

[JPT]

i think you are referring to the charcoal canister. i had that replaced because it was cracked. my gas cap i replaced was from auto zone.. maybe i need to get an em one from the dealer. might try that tomorrow.

No, one mine it is next to the canister. It is some type of a valve. It may not be on he I equipped truck. I think it is called the NVLD or something like that. It checks for leaks.

A video about it:
http://youtu.be/Ox2B0pwGNIU

 

[Bkoff13]

I thought my cap was bad at first based on the codes. Filling the truck with gas was hard because the pump handle would not seal. If this is happening to you follow the lines coming from the filler neck. I found one that had come apart on its own. I reconnected it and cleared the codes. I haven't had a problem since.

 

[GreenClassic]

I was told by the guy that did my smog check not to get generic gas caps at auto parts stores. He said he has seen many caps fail after just a couple months. Something about how the seal is cheap rubber and will swell up and crack.

Although, I will admit that my generic cap lasted 4 or 5 years.

 

[Tach_tech]

If possible, use an OEM gas cap, I've seen many aftermarket caps not seal properly. Also it's fairly common for the NVLD to be faulty which will set a dtc for an Evap leak even when there isn't one.

 

[ram5.7hemi]

Is the filler neck opening that the cap seals against metal or is it plastic coated? If it's metal and has rust on it, that might be your leak (which might not show on a smoke test). Take some wheel bearing grease and smear it on the rim of the filler tube and put the cap back on (clear the CEL if you can) and see if it comes back on.

Had to do that on my '01 1500 every 2~3 months to keep a seal. Also have a coworker with a '00 Bonneville SSEI that needs to coat his entire filler tube with grease every couple of months to keep it from venting and causing a CEL (a $5 can of grease goes a long way and is a lot cheaper than a $900 fuel tank).

its metal and in good condition.. no rust or anything.. the whole truck is actually very clean.

 

[ram5.7hemi]

If possible, use an OEM gas cap, I've seen many aftermarket caps not seal properly. Also it's fairly common for the NVLD to be faulty which will set a dtc for an Evap leak even when there isn't one.

thanks, i thought of that too just picked up a molar gas cap today from dodge dealership. whats the NVLD?

 

[JPT]

thanks, i thought of that too just picked up a molar gas cap today from dodge dealership. whats the NVLD?

Its what I posted a link to earlier in this thread. It checks for leaks in the system. Sometimes it goes bad and reports to the system that there is a leak, even if there isn't.

Mine went bad, I jumped ahead and replaced it before doing a smoke test to save money, because I could return it if it wasn't the problem. In my case it was the problem. This was step 2 after replacing the gas cap with an OEM cap.

https://www.youtube.com/watch?v=0QCLqXx6SGI

 

[rboyer1290]

Make sure the seal is on the leak detection pump! I just went through this and the new canister didnt come with the seal.

 

[Ares_288]

I had similar issue. I changed to a locking gas cap from Amazon and have not had a problem since.

 

[ram5.7hemi]

Its what I posted a link to earlier in this thread. It checks for leaks in the system. Sometimes it goes bad and reports to the system that there is a leak, even if there isn't.

Mine went bad, I jumped ahead and replaced it before doing a smoke test to save money, because I could return it if it wasn't the problem. In my case it was the problem. This was step 2 after replacing the gas cap with an OEM cap.

https://www.youtube.com/watch?v=0QCLqXx6SGI

thanks I've watched that video and a couple others... when i went to look for it though i can't find it... where is it sops to be? is it possible i don't have one? i see my canister and a round cylinder looking thing... nothing that looks like that... at least not in that area....?

 

[ram5.7hemi]

Make sure the seal is on the leak detection pump! I just went through this and the new canister didnt come with the seal.

where is the leak detection pump? where should i look for a seal at..?

 

[rboyer1290]

where is the leak detection pump? where should i look for a seal at..?

It's on the canister, has a hose and a connector on it.

 

[ram5.7hemi]

It's on the canister, has a hose and a connector on it.

I think I know what your talking about. I checked and everything seams tightly sealed there... I did trace lines that I could and found one line the comes from the canister and runs up the drivers side of the truck disconnected by the drivers door.. I has a rubber piece connect but was not clapped. So I bout a couple clamps and put them on and cleared all the codes