My gas cap for some reason keeps coming lose after a couple of day. This is really annoying because it will spill gas over and onto the side of the body. Should I just replace the cap or is there another fix?

 

Have you removed the charcoal canister? If not, check it's operation and make sure it's okay. It is supposed to be venting the pressure in the tank. Also....

1. Have you swapped gas caps?

2. How's your mileage? Any chance you're seeing the remnants of someone siphoning gas out of your car?

 

not sure been doing for a couple of weeks, thought at first that the cap wasn't tightend by the service station attendants but i got to where i would check and has indeed tight.

Haven't removed the chacoal canister, would it effect the the cap coming lose?

Could have been siphoned with out me looking.

Never changed the cap before.

 

Sounds like the little green trolls live in your car too, shhhh theyre listening.

 

Possibly. The charcoal canister is how the tank pressure gets vented. Maybe the pressure is building up and popping loose the gas cap?

Siphoning is more likely probably. Hopefully they're not adding something else to you tank.

Ever thought about a locking gas cap? Might be a fairly cheap quick solution if the canister is working okay....

 

I thought the canistor is for gas vapor, to filter and burn it in combustion instead of venting it to the atmosphere. Isn't there a fourth fuel line from the tank for pressure relief.

 

Whats a good way to check the canister?

 

Is the "Evaporative Emission Canister" and the Charcoal Canister the same thing? If not, where are they located in the car.

When the car has been running awhile and you shut it down, I get a noise from the area of the gas tank. Turn the Gas cap a little counter clock wise and the tank vents through the gap causeing the noise to stop. However the garage then smells strongly of gas.

Could the canister be clogged and the pressure being released through a back up valve in the back of the car or is it something else ?!?.

I posted here beacuse it seems to be a related tread. Thanks

 

Hmm, possibly the "flatulation valve?"

*edit* Or wait...thats to let air in...nm.

 

I had to deal with this after I broke a vacuum hose for the charcoal canister pressure control valve. I ended up just plugging it with a cap and noticed that everytime I filled up my tank, the gas cap would make a noise that sounded like a lot of pressure was being released. I made a trip to Pepboys shortly after and fixed it, and the noise seemed to go away.

I don't know what the effect of pressure can have on a gas tank, but I've heard it's not a good idea to let a lot of pressure in there.

I'd check the vacuum lines from the gas tank to check valve, check valve to canister, and check valve to PCV. All of those lines could be broken and not allowing vacuum to reach them. If they are all ok, consider purchasing a new check valve (if you can find one).

And yes, the "Evaporative Emission Canister" is the same thing as the charcoal canister.

 

Thanks... were is the check valve located and what is the "PCV"
Primary Control Valve??? (walks out to garage to start poking his head about)

 

Positive Crankcase Ventilation.
The valve should be mounted in a rubber grommet on top of one of the valve covers.

 

The check valve should be almost right next to the canister itself, and it will have three hoses connected to it, IIRC. It looks like a small saucer shaped valve.

Here is a diagram of where all the vacuum hoses are supposed to be connected under your hood. This is for an LG4 with a/c:



EDIT: I just noticed you have an L98. I'm not sure this information applies to you, but I'm sure the canister has some kind of pressure vent line in there on the L98, too.