I'm thinking that it's this:

https://www.youtube.com/watch?v=6ZCTOc78sSU&t=15s

Due to work, I can't start taking stuff apart until this weekend.

No changes in driving characteristics, no check engine light, no obvious signs of fuel leaking.

Question:

the car is 16 years old with 189k on it. Can I use silicone to seal it or should I just replace the entire cap? Not really trying to spend too much money on a 16 year old car.

Anything else I should look at first? Maybe the gas cap?

Any suggestions/advice are appreciated.

You do not fool around with something like this. Get a mechanic to check it out.

I've got an 02 Civic Si. I'm assuming it's similar in the sense that the fuel pump is accessible under the rear seat cushion. Any smell of fuel in the engine compartment? Does the manual show an O-ring between the cap and fuel pump? Has the car always been stored outside (hot temps etc)?

I wouldn't wait to this weekend. Two 10mm bolts to remove the rear seat cushion and do a quick inspection. I'd replace the entire fuel pump at this point if you've got to remove it. Will silicone hold up to gasoline? I guess it can't hurt to apply silicone for a quick fix to see if that cures the vapors.

As for the Youtube video, that seems like a lot of work to create a tool that probably already exists. Check Autozone etc for tool loan.

Wait to fix it for sure.

I mean what could go wrong with gas leaking in an automobile?

It's not like it's aa fire or health hazard like your kids old GoGurt tube or apple core.

<strong smell of sarcasm>

Sure - hold off. Avoid smoking in the car.

I’ll take care of it Saturday morning. Have school tomorrow night and work Friday. I’m not a stranger to turning wrenches. Might just do a quick fix and order the part online. Was really trying to get this car to next year after we move into our home.

No smell of fumes while I’m parked which leads me to believe it’s minor. Went into the garage today and smelled the gas. Immediately moved the car outside. Tank is only half now and will keep it around that level until I fix it for good. Fortunately, my drive to work is down to 20 miles round trip.

quote:

Will silicone hold up to gasoline?

Some will and some most certainly will not. Make sure you get the right kind.

quote:

...leads me to believe it’s minor.

There's nothing minor about a gas leak.

quote:

Originally posted by jhe888:
Sure - hold off. Avoid smoking in the car.

Why chicken out like that?

Light 'em if you got 'em!

quote:

Why chicken out like that?

Light 'em if you got 'em!

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Where is the meme??? I am confused.

Even if silicone sealant didn't dissolve in gasoline, there is no fuel sealing application where its use is ever appropriate. Put that out of your mind.

I doubt if a strong smell inside just comes from a loose or even missing gas cap, but on the other hand, gas caps are cheap. I'd check for a leaking fuel line under the hood or something. Have you lived anywhere other than Florida or El Paso where a car is subject to rust? A steel fuel line might be rusted through underneath. Another possibility is a fuel line or even pump on top of the gas tank. Any gas running down the sides of it?

I would drive it from outside of the car, if you could, you know, rig up some cables to the gas pedal and steering wheel and shit.

Or let your cat drive maybe? They are impervious to the smell of gasoline.

And they run fast and stay right on that hairy err furry edge of the fireball when all goes wrong. Looks really cool if you catch it with one of those new HD slo-mo phones.

quote:

Originally posted by parabellum:
I would drive it from outside of the car, if you could, you know, rig up some cables to the gas pedal and steering wheel and shit.

Maybe stick a chair up on the roof?

I would not use silicone. Fix the problem correctly.
Look at every part of the fuel system that you can see, from the tank to the engine area. Fuel will evaporate, and soon if the nearby parts are hot or even warm. You will usually see some sort of a stain or residue even after it's evaporated. It doesn't take much to make a smell. If the problem is the pump, as shown in the video, there should be some stains or even signs of fuel leakage along the sides or bottom of the tank that you should see from the bottom.

Park it outside until you fix the problem and preferably away from other cars when in a public parking area.

I watched the video. Unlike that guy, try to use up as much of the gas as you can before you do this. Have a can of two of brake cleaner and a roll of paper towels to clean up around the top before removing the pump. You don't want to get the dirt into the tank or under any part of the gasket. DO NOT use a shop vacuum to clean up around the top of the tank, the motor makes sparks inside and the fumes will go off.

You probably don't have the tools to fabricate the ring removal tool like the guy in the video. Two large and long screwdrivers or pry bars, crossed like an X and engaged on the ribs of the retaining ring should work fine to unscrew it.

quote:

the car is 16 years old with 189k on it. Can I use silicone to seal it or should I just replace the entire cap? Not really trying to spend too much money on a 16 year old car.

I drive old cars,and have had to take gas cap off clean well with dish soap and water.
Then use vasoline on the rubber O ring .makes a good seal and warning light goes off.
I don't think its the cap with vapors in cabin.

Where is the fuel filter on this car? I once had a leaking fuel filter under the hood...made the car smell like gasoline.

We have a 2002 Subaru AWD with a lot of miles on it. Last winter during extended cold weather events, a raw gas smell would makes its presence known.

It turned out to be a very short piece of rubber tubing with spring loaded clamps on each end. Age and engine heat had taken its toll on both hose and very small clamps. A new 2 inch piece of hose and a couple of new screw tightened clamps = no more raw fuel smell.

It could be a very simple solution.

Onion rings. Just say’n.