Intermittent Gas Cap alert

[heymrdj]

Gf's parents have a 07' Pontiac G6 base model with the 4 banger. In this last month the Check Gas Cap alert has flashed up on the radio display, and the only way to fix it is to pull over and fully loosen (with a loud hiss of pressure when I do), then fully tighten the gas cap. That's the only way I can get the message to disappear. It's completely random, but on average 1 out of 8 trips to town it'll do it. The trips are about 8 miles each time, very few bumps, all asphalt driving, mostly in the 35mph - 60mph area. The car does have warranty (extended manufacturer), but with the problem so intermittent we're trying to see a starting point to look into the problem.

Really appreciate the help!

EDIT: Oh and to follow guidelines, no modifications, oil changes at about every 5,000 miles, and it just turned 29,000 on the ODO.

 

[BassBomb]

are you overfilling?

 

[heymrdj]

No the tank is only filled until it clicks the first time, we don't "bump" the pump. Most of the time the tank is not full. In fact it happened today with between 3/4 and 1/2 tank of gas, and the time before that (bout 1 week ago) with 1/4 - 1/8 tank of gas.

 

[LTC8K6]

I think the gas cap is an emissions item, so I think it's warranted for a long time.

The problem could also be with the vapor recovery system.

 

[RagingBITCH]

I'd try a new gas cap...easiest/cheapest thing to try/rule out.

 

[boomerang]

Originally posted by: LTC8K6
I think the gas cap is an emissions item, so I think it's warranted for a long time.

The problem could also be with the vapor recovery system.

Yes, but I'd vote for the latter. The cap is doing its job which is holding pressure. It's emissions related which is under the original warranty. Take it in and tell them what you told us.

 

[heymrdj]

Originally posted by: boomerang

Originally posted by: LTC8K6
I think the gas cap is an emissions item, so I think it's warranted for a long time.

The problem could also be with the vapor recovery system.

Yes, but I'd vote for the latter. The cap is doing its job which is holding pressure. It's emissions related which is under the original warranty. Take it in and tell them what you told us.

That's the problem, why we were trying to get a clue as to what it was. The car is used daily for work, and the second car is also used daily. If they said all of a sudden they need the car for a week, the family would be in hot shit for transportation. I'll try to pull some strings and get the car in.