Gas tank pressure

[urdrwho]

This example happens after driving for a while never when I first start the car.

 

On my 95 L wagon I notice that there is a bit too much gas tank pressure behind the gas cap. I notice a rather healthy big whoosh of pressure when I remove the gas cap.

 

This car is not my daily driver. On my daily driver I have a 2.5 psi valve that opens and allows the vapors to enter the carbon canister. I am wondering if the 95 has a problem with the carbon can or the pressure valve. Which BTW I am not sure where the pressure valve would be but I'm guessing it is the little valve directly before the carbon canister.

[Sludgeroo]

Mine does it also, it hard to say how much pressure is being released by your verbal discription.

 

I can tell you the carbon canister/evap canister is under the passenger side rear bumper. Looks like if you had fuel cell an a walbro sticking out of the bottom minus the fancy AN fittings.

 

I believe the pressure check valve is somewhere in that line because it isn't far from the tank at all.

 

Let us know what you find, and GL

[urdrwho]

Unless there are two canisters, on my 95 the canister is located in the engine bay, on the right, at the front. There is a small valve located direct before one of the hose bibs on the canister.

 

Maybe I should pull the canister and see if the charcoal is still loose and free? But if the canister was bad I should get a code.

 

Mine does it also, it hard to say how much pressure is being released by your verbal discription.

 

I can tell you the carbon canister/evap canister is under the passenger side rear bumper. Looks like if you had fuel cell an a walbro sticking out of the bottom minus the fancy AN fittings.

 

I believe the pressure check valve is somewhere in that line because it isn't far from the tank at all.

 

Let us know what you find, and GL

[Sludgeroo]

This is true, can you take picture of the canister in the engine bay that you are referring too?

 

At work and can't come out to peek at my car

[subikid90]

The 98+ has the canister under the trunk. The earlier models have it in the engine bay on the passenger side behind the headlight/radiator

[Sludgeroo]

Goddamn! I have so many exceptions being a 99. Thanks kyle.

[urdrwho]

It is hard to describe the amount of pressure. The only thing I can say is I have 4 cars and the Subbie has a lot more pressure than any of the other cars. If you turn the cap gently, barley holding the cap, I imagine that the pressure would push the cap up. It isn't like it would blow the cap out past the flap but it would push it more than any of my other cars.

 

The only CEL I get is an occasional 400. I've cleaned the TB, changed the EGR valve, cleaned the ports, sensors check out, etc. I talked to one guy that said excess tank pressure could throw a 400 code.

 

The car runs 97% perfect, maybe I shouldn't complain.

 

Mine does it also, it hard to say how much pressure is being released by your verbal discription.

 

I can tell you the carbon canister/evap canister is under the passenger side rear bumper. Looks like if you had fuel cell an a walbro sticking out of the bottom minus the fancy AN fittings.

 

I believe the pressure check valve is somewhere in that line because it isn't far from the tank at all.

 

Let us know what you find, and GL

[Sludgeroo]

Just rub some dirt on it and call it a day LOL.

 

I would wait until it becomes a real pain in the ass