06 Liberty with "GASCAP" light

[narntek]

Have another interesting one for someone to try and figure out, since the people at the dealer can't find an error code, or a rhyme or reason as to why this is happening.

My mother owns an 06 Liberty with 162k on it. She purchased it with around 12k miles on it, (we're a Libby family ) and has loved owning it. Recently, a new issue has been presenting itself, and our dealer that we bought it from & have taken it to all of it's life with us cannot figure out what exactly is wrong with it, they can't seem to duplicate the issue.

Around 160k, the CEL came on. Thought it was maybe just because it's an older car with higher mileage, that, that was the reason that the light was on. I've had a couple of beaters in the past with CEL's and nothing was remotely wrong with them. About a week after that happened, the odometer started cycling from the mileage, to GASCAP. This is remedied by pushing the trip OD toggle and goes away until the next time the truck is started.

It has always seeped a little gas while refueling, but it never has done it to a major extent. This could relate to the problem, so I threw it in as an additional detail.

Any suggestions would be great.

 

[LibertyTC]

Try to get a new gas cap from dealer. Not expensive, the seals on cap do wear out.
If the system senses a leak, the light should come on.
I replace my gas cap every 5 years it seems. :gr_grin:

 

[profdlp]

The gas burp is common and shouldn't be a factor. My GASCAP warning came on one time late last summer as I was pulling out of the parking garage at work. I pulled over, shut the engine off and removed the key, then removed the gas cap replaced it. The warning came right back on. I repeated this and the notice never came back.

I'm with TC - replace the cap. Even if it doesn't help you are only out ten bucks or so. I would also check the vacuum lines under the hood. I don't know if they could cause this exact problem but I suppose it's possible.

By the way: I started adding Marvel Mystery Oil to the gas tank last summer and my fuel burp problems were noticeably diminished. It took 2-3 tankfuls for this to occur. There is an excellent write-up around here somewhere telling how to permanently fix the problem. It involves replacing the one-way valve in the filler tube and takes a little doing, though it looks to be by no means extremely difficult. Apparently this valve sticks "open" and never signals the pump that pressure has risen enough for the automatic shut-off to occur.

 

[narntek]

I guess I should have explained more, I put the original cap back on after cleaning it, and then replaced the cap. The light is still on. It's not running noticeably any different then before this started happening. It has gone thru an amazing amount of tail light bulbs in it's lifetime, but that's beside the point :icon_razz:

As far as the "gas burp" issue, I've only filled up that particular KJ a handful of times. I have my own rig and hardly ever drive hers, but mine has never had that issue since I purchased it.

The gas burp is common and shouldn't be a factor. My GASCAP warning came on one time late last summer as I was pulling out of the parking garage at work. I pulled over, shut the engine off and removed the key, then removed the gas cap replaced it. The warning came right back on. I repeated this and the notice never came back.

I'm with TC - replace the cap. Even if it doesn't help you are only out ten bucks or so. I would also check the vacuum lines under the hood. I don't know if they could cause this exact problem but I suppose it's possible.

By the way: I started adding Marvel Mystery Oil to the gas tank last summer and my fuel burp problems were noticeably diminished. It took 2-3 tankfuls for this to occur. There is an excellent write-up around here somewhere telling how to permanently fix the problem. It involves replacing the one-way valve in the filler tube and takes a little doing, though it looks to be by no means extremely difficult. Apparently this valve sticks "open" and never signals the pump that pressure has risen enough for the automatic shut-off to occur.

 

[uss2defiant]

evap issue?

 

[Kal-El]

I'm sure the 06 is different from my 04, but changing the purge solenoid and the leak detection pump fixed my PITA leak problem. Also made sure that the lines back and forth to each were good.

 

[tjkj2002]

I guess I should have explained more, I put the original cap back on after cleaning it, and then replaced the cap. The light is still on. It's not running noticeably any different then before this started happening. It has gone thru an amazing amount of tail light bulbs in it's lifetime, but that's beside the point :icon_razz:

As far as the "gas burp" issue, I've only filled up that particular KJ a handful of times. I have my own rig and hardly ever drive hers, but mine has never had that issue since I purchased it.

Only use a MOPAR cap from the dealer,plus you need to clear the EVAP code from the system or wait 50 some drive cycles without failure and the PCM will clear the code for you.

If that does not work you need to get it diagnosed with a smoke machine to find the leak.

 

[narntek]

Found a guy that is a mechanic that lives reasonably close to me. Had it scanned, and it's coming back as an Emissions/EVAP sensor error. I don't have the exact code at the moment. I was told it was something that would eventually needed to be tended to, but it isn't the gas cap that is actually triggering the warning. The CEL is triggered because of the evap error. It has a recall due on it, so when the dealer calls me when the parts come in, I'll have them get me an estimate on that.

Only use a MOPAR cap from the dealer,plus you need t
o clear the EVAP code from the system or wait 50 some drive cycles without failure and the PCM will clear the code for you.

If that does not work you need to get it diagnosed with a smoke machine to find the leak.