I'm having a hard time filling up my 7. I know the cap isn't vented but, the pressure built up after driving seems way out of the normal. Open gas cap and it is almost like a big-rig letting off the brakes. Searching, it seems most people just drill a hole in the gas cap. I'm wondering however if there is a vent/overflow tube on the 2nd generation that is prone to getting clogged by insects mainly mud dauber wasps and various spiders? I don't have the car with me this weekend as I'm away for business so I'm relying on you all, as I cannot check it myself.

Providing there is a vent tub and that is the issue, could one put a screen/mesh over it to prevent it for reoccurring?

 

Anyone?

 

The fuel tank vent goes through a hard line into the engine bay. (it is the third hard line along the underside with the fuel feed and return lines.) It goes up the firewall, then crosses over with another hard line and is plumbed into the charcoal canister on the passenger side of the engine bay.

I had the same issue you did, though not quite "big rig brake" status, so I removed my charcoal canister as it was very obviously clogged, and plumbed it into my catch can.
Some people remove everything and let it vent over on the driver side.
I have read of people being worried about fuel vapor/spitting out near the coils though; I would be too.

Instead if you don't have a catch can I'd run a road draft tube or atleast a cheap 5 dollar parts store filter on the passenger side hard line. You will occasionally smell fuel in the engine bay when/if you get rid of the charcoal filter though.

 

even if you remove those parts and vent it the fuel tank will still build pressure. honestly it is normal.

my TII has no fuel tank vapor system any longer and i just ran it through emissions, the way he tested the system was to just spin off the cap and listen to the air escape.. heh

 

Why do people think that this is such a big deal?... Or even a 'new' issue? It's even normal to see high fuel tank pressure from normal driving.

The cap states, "WARNING remove slowly. Fuel may be under pressure. Spray may cause injury."

 

maybe it should say: "do not hold an open flame near fuel filler door while removing cap, some fire may occur"

all my cars build pressure in the tank, it's called thermal expansion and vaporization.

now if it was creating a vacuum, then i would be concerned! if the whole issue is filling the tank then try a different filling station, most of the problems filling the tank aren't your car but from the overflow mechanism on certain pumps being overly sensitive. the EPA governs how much fuel vapor is allowable to spill from pumps while pumping, of course over time the standards become too strict and eventually you probably will not even be able to pump gas in summer because the vapors will lock the pumps. don't get me started on the jerry gas cans with these safety locks that supposedly keep vapor spilling to a minimum, i spill 10 times as much gas with those stupid things as i ever did with a simple pull spout can... but you know, they are smarter than the average consumer!

drilling a hole in your cap or venting the tank remotely won't address that issue. just say no to pumps that think they are smarter than you.

 

The issue isn't so much the pressure. It is the prevention of filling the tank (at pump) supposedly due to the expelling vapors.

I didn't think it would as well the cap is off when it's filled anyways.

So far that is 11 different filling stations over the past couple weeks, all that are on my route to/from work (excluding Casey's.) I've successfully filled it using plastic gas cans since I have owned the car. Huge pain.

The only reason I bring the high pressure up is because, as far as I know it is the only thing I can think that would be causing this problem I'm having.

 

well, there is no vent above the opening you use to fill the tank at the filler neck so the fuel has to go in at a certain pace(blocked or not makes no difference). i usually run into the issue when ambient temps are above 100F but working the pump nozzle at different angles usually works, some pumps i just feel like taking a sledgehammer to, others work perfectly without issue.