Gas Cap Problems!!
Thread Starter
Melting Slicks
Joined: Feb 2011
Posts: 2,840
Likes: 65
From: Tree City
Gas Cap Problems!!
-------Well, here's my story.
Yesterday I took my (2005) car to our club picnic. I drove it about 150 miles in all. I got home last night about 9:30 and I stopped my car in front of the garage, got out and opened the garage door. When I get back into the car, I notice the engine light is on. Uh-oh!! 
Oil pressure is good. Temperature is good. So I pulled it in the garage and shut the engine off. Start it up again- same thing, engine light on.
-------I got out my manual and read: The light can come on if I recently put gas in the car. Ah-hah!! I had just filled it up earlier in the day. But how do I get the light to go off?
-------Then I came out this morning read that the gas cap could be on improperly. No, it couldn't be that. The gas cap was new last fall. And I was always told to put the cap on ever so lightly. It always worked perfectly before this with the cap on slightly.
--------So, I took the cap off, put it back on a few times and I got the same thing. Then I put it on and gave it about three spins. Bingo!! The light goes out. So now, after putting it on lightly all this time, I am going to have to put it on tight to keep the light from coming on. Oh well. At least the light has gone out.......for now.
Yesterday I took my (2005) car to our club picnic. I drove it about 150 miles in all. I got home last night about 9:30 and I stopped my car in front of the garage, got out and opened the garage door. When I get back into the car, I notice the engine light is on. Uh-oh!! Oil pressure is good. Temperature is good. So I pulled it in the garage and shut the engine off. Start it up again- same thing, engine light on. -------I got out my manual and read: The light can come on if I recently put gas in the car. Ah-hah!! I had just filled it up earlier in the day. But how do I get the light to go off?
-------Then I came out this morning read that the gas cap could be on improperly. No, it couldn't be that. The gas cap was new last fall. And I was always told to put the cap on ever so lightly. It always worked perfectly before this with the cap on slightly.
--------So, I took the cap off, put it back on a few times and I got the same thing. Then I put it on and gave it about three spins. Bingo!! The light goes out. So now, after putting it on lightly all this time, I am going to have to put it on tight to keep the light from coming on. Oh well. At least the light has gone out.......for now.
Pro
Joined: Jan 2003
Posts: 730
Likes: 45
From: kansas city mo.
Had the same problem with the cap after every fill up. I did the turn with no pressure and after 15 or so miles the light would come on. After playing with the cap it would go away in a day. I went and bought a OBDII and hadn't had the problem after I got it. But I'm waiting.
Le Mans Master
Joined: Feb 2007
Posts: 8,514
Likes: 235
From: Currently somewhere in IL,IN,KY,TN,MO,AR,MS,AL, or FL
It takes about 10 minutes after starting the car for all of the fuel system pressure tests to be completed. The fact that the light went out after 10 minutes of fiddling is probably coincidence.
Yes, there was a TSB for the fuel system that included new software for the BCM because the level sensor "debounce" timing was too short. It allowed for a longer period of failure of a level sensor before declaring a fault and setting a code.
But, OP, you didn't get the gas cap message on the DIC. You just found something in the manual that said it COULD be the gas cap among the hundreds of other possibilities for a Check Engine Light. Why assume it was the gas cap at fault? Maybe (probably) it was but without reading the codes there is no way to tell for sure. Let us know if the issue returns and don't go spending a lot of money trying to fix a fuel system issue when it could be something as unrelated as a wheel sensor or oil sensor or...
Yes, there was a TSB for the fuel system that included new software for the BCM because the level sensor "debounce" timing was too short. It allowed for a longer period of failure of a level sensor before declaring a fault and setting a code.
But, OP, you didn't get the gas cap message on the DIC. You just found something in the manual that said it COULD be the gas cap among the hundreds of other possibilities for a Check Engine Light. Why assume it was the gas cap at fault? Maybe (probably) it was but without reading the codes there is no way to tell for sure. Let us know if the issue returns and don't go spending a lot of money trying to fix a fuel system issue when it could be something as unrelated as a wheel sensor or oil sensor or...
Thread Starter
Melting Slicks
Joined: Feb 2011
Posts: 2,840
Likes: 65
From: Tree City
I bought the car used, so there is no warranty now unless I renew it before 30,000 miles. But the light went out, so now it is OK. I hope.
Thread Starter
Melting Slicks
Joined: Feb 2011
Posts: 2,840
Likes: 65
From: Tree City
It takes about 10 minutes after starting the car for all of the fuel system pressure tests to be completed. The fact that the light went out after 10 minutes of fiddling is probably coincidence.
Yes, there was a TSB for the fuel system that included new software for the BCM because the level sensor "debounce" timing was too short. It allowed for a longer period of failure of a level sensor before declaring a fault and setting a code.
But, OP, you didn't get the gas cap message on the DIC. You just found something in the manual that said it COULD be the gas cap among the hundreds of other possibilities for a Check Engine Light. Why assume it was the gas cap at fault? Maybe (probably) it was but without reading the codes there is no way to tell for sure. Let us know if the issue returns and don't go spending a lot of money trying to fix a fuel system issue when it could be something as unrelated as a wheel sensor or oil sensor or...
Yes, there was a TSB for the fuel system that included new software for the BCM because the level sensor "debounce" timing was too short. It allowed for a longer period of failure of a level sensor before declaring a fault and setting a code.
But, OP, you didn't get the gas cap message on the DIC. You just found something in the manual that said it COULD be the gas cap among the hundreds of other possibilities for a Check Engine Light. Why assume it was the gas cap at fault? Maybe (probably) it was but without reading the codes there is no way to tell for sure. Let us know if the issue returns and don't go spending a lot of money trying to fix a fuel system issue when it could be something as unrelated as a wheel sensor or oil sensor or...
Team Owner
Joined: Oct 2004
Posts: 27,420
Likes: 64
From: San Clemente CA
Buying new or used makes no difference for emissions warranty. I have a letter by GM issued August 2008 that extends the gas cap warranty on the 2005 to 10 years or 120,000 miles. They will give you a new one. 
Race Director
Joined: Dec 2010
Posts: 18,097
Likes: 1,595
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Thread Starter
Melting Slicks
Joined: Feb 2011
Posts: 2,840
Likes: 65
From: Tree City
OK. Thanks. I just got a new gas cap (which I bought last fall). It hasn't had more than 300 miles on the car since then. But if I continue to have problems, I'll give it a shot. Thanks so much guys.
Thread Starter
Melting Slicks
Joined: Feb 2011
Posts: 2,840
Likes: 65
From: Tree City
Had the same problem with the cap after every fill up. I did the turn with no pressure and after 15 or so miles the light would come on. After playing with the cap it would go away in a day. I went and bought a OBDII and hadn't had the problem after I got it. But I'm waiting.
Team Owner
Joined: Dec 2003
Posts: 57,408
Likes: 164
From: queensbury ny
I bought the car used, so there is no warranty now unless I renew it before 30,000 miles. But the light went out, so now it is OK. I hope.
Thread Starter
Melting Slicks
Joined: Feb 2011
Posts: 2,840
Likes: 65
From: Tree City
10 years/120,000 mile warranty is in effect,but you'll get the same gas cap and it will break again. I bought one from an auto parts store one year out at Carlisle when mine went. Never needed another one after that...and I was replacing my 3rd one under that warranty.
Team Owner
Joined: Dec 2003
Posts: 57,408
Likes: 164
From: queensbury ny
Last year my "Replace Gas Cap" message kept coming on so that is why I got a new GM cap. What brand did you get?
Melting Slicks
Joined: May 2010
Posts: 2,037
Likes: 331
From: Long Island New York
Had the gas cap problem awhile back, took it to the dealer and they replaced it free of charge, warrantied. Message came back on a few months later, I went to the local parts house and bought a Stant, about $16, no more problems!
Thread Starter
Melting Slicks
Joined: Feb 2011
Posts: 2,840
Likes: 65
From: Tree City
I thought people had told me not to put it on until it clicks. To only put it on very lightly and not let it click. This is the way I had been doing it. Maybe yesterday I didn't put it on tight enough to begin with. I don't know. But since I bought this new one, I haven't been tightening it up that tight and it has worked fine. Oh well. I'll have to see. Thanks
Team Owner
Joined: Dec 2003
Posts: 57,408
Likes: 164
From: queensbury ny
I thought people had told me not to put it on until it clicks. To only put it on very lightly and not let it click. This is the way I had been doing it. Maybe yesterday I didn't put it on tight enough to begin with. I don't know. But since I bought this new one, I haven't been tightening it up that tight and it has worked fine. Oh well. I'll have to see. Thanks
Drifting
Joined: Feb 2012
Posts: 1,428
Likes: 113
From: Brick NJ
It's your onboard diagnostics computer, and you can go to many Auto parts store that will let you borrow their scanner to retrieve the codes, also you can't over tighten your gas cap spin it a couple of clicks and your good.
