bvnguyen516

excessive fuel smell coming from the right underside of the car. didnt hit/scape anything recently, and I think there is a hissing noise associated...

of course, i'm thinking there is some sort of fuel line or something leaking..

shop isnt open today (sunday), any ideas?

Macster

My WAG is something related to the fuel tank vapor recovery system is leaking, unless you tell me you see liquid gasoline then a fuel line or possibly even the fuel tank comes under suspicion.

Regardless, the problem is not going to go away on its own and there's not anything you can do unless you are prepared to gain access to the area (behind the passenger side front wheel and under the passenger fender) the fuel vapor recovery system resides.

However, I'm always rather reluctant to tackle fuel system problems myself (age has put some fear into me) I'm even more reluctant to attempt to advise someone on his own to tackle a fuel system problem.

My advice is to have the car flat bedded to a qualified shop for professional diagnosis and repairs.

I would avoid starting the engine or even messing about around the car. If you smell gas you are very likely encountering an ignitable cloud of air and fuel vapor. A static electric discharge may be all it takes.

Hope the car is not parked next to a gas water heater.

Sincerely,

Macster.

bvnguyen516

Macster,

Thanks for the input, It's not parked next to anything that I would suspect could light any possible build up fumes.

Question about the fuel vapor system, do you think it would "leak" fumes or vapors while the car is off..?

B

Macster

Gasoline constantly generates vapor. A open container of gas left out over time will have the gasoline evaporated completely in less time than you think in all but the most coldest climes.

If the vapor recovery system has a leak this can allow fumes from the tank to vent to atmosphere.

So the short answer is yes.

Sincerely,

Macster.

bvnguyen516

So the shop could not identify anything as the problem. Their theory is that, it was the venting mechanism (never heard of a fuel venting mechanism..) and since it was like 95 degrees, I was just being "sensitive to the smell of gas".

No one else could smell the profuse scent of fuel when I was "freaking" out... Maybe Im just crazy...

B

Macster

Well, it's a theory.

I do not know the circumstances under which you smelled gas. It is possible you smelled some coming from or that had recently come from the exhaust system. The first whiff can be overpowering and make one believe the Exxon Valdez ran aground nearby. But gas has the tendency to make the nose less sensitive to the odor of its vapor so after the 1st whiff what one thinks is just a passing smell of gas may be just one's nose partially shutting down from the initial whiff.

Modern fuel systems are designed to not release gas vapors to atmosphere under AFIAK any conditions, no exceptions, as long as they're working properly.

What normally happens is under some conditions the DME will open an air vent and some other valving that results in engine vacuum pulling in outside air into and through the charcol canister to remove the gas vapors the charcol has absorbed while the car has sat for a while. These vapors are routed into the intake manifold of the engine and burned in the engine.

The result is while the gas in the tank emits vapor the charcol in the canister absorbs it so it doesn't have to be vented to outside air.

I can't recall ever when being around my cars hot or cold or anywhere in between, parked outside in the sun, in still air, or parked hot inside an enclosed (garage) space, ever smelling gas unless I had just driven the car into say the garage or parking space and the engine was cold and of course emitting unburned gas as these engines are wont to do when cold.

But if you trust the shop.

Just make sure when you fill up the tank you do not fill the tank to the brim. Be sure not to spill gas from the nozzle into the gas tank filler cavity. Be sure to install the gas cap correctly and tighten it securely. Do not overtighten.

Give the car a sniff once in a while. If you smell gas...

And of course if you ever see liquid gas under the car, or signs gas might have been under the car then evaporated, well, there's a fuel leak.

In short, just keep your eyes and nose open.

Sincerely,

Macster.

avader906

Please alo check for cracks on exhaust manifolds and the rest of the system. If there is a crack/leak in manifolds it will run rich and could smell gas + ticking/hissing noise.