Fuel Tank Noise, like a lot of gas is sloshing around...
 

Of all the strangest problems i've had with my car, this one takes the cake. I have a 1997 C36 with 106,000 miles.

Was running low on gas last night and went to Chevron to fill-er-up. That went un-eventful, except I was now down $26.

Anyhoo, I drive home, approx 2 miles from the station.

When i get out of my car, I immediately hear what sounds like a "gurgling" sound from my trunk area. It sounds like liquid that's being emptied from a large plastic bottle, like when you pour out a 2-liter soda bottle and the air inside is escaping, causing irregular flow of the soda along with a "gurgling" sound. Sorry, I don't know how else to describe it....

Except it was loud enough to hear outside the car.

It was definintely where the fuel tank was...and I can imagine it must be the gas.

This happenned for about 5 minutes off-and-on. It would make the sound for 10 seconds...stop...then come back a few seconds latter.

Very un-nerving!

I was thinking my gas-tank ruptured or something, but so far I haven't seen any leaks from the car. No gas smell outside the car either.

I started the car this morning and it was fine. No more sounds at this time.

This is the first time i've ever heard this noise. And of course i've fueled my car hundreds of times.

I did some research on the forum and the only thing I came up with that may have something to do with it is the purge-valve in the fuel system, or the fuel pump. But I don't know if this would cause such a sound...and why now.

Has anyone else experienced this? And any ideas what this could be?

TIA :)

Did you "top off" the tank?

You may have gotten enough fuel into the expansion tank to cause air to bubble back through the vent lines as the tank emptied slowly into the main tank. I stop when the filler pops closed -- I loose enough fuel out the cap on the 280 as it is, no need to have fuel up there any longer than necessary.

If the temp outside was much higher than the fuel temp when you filled, the gas may have expanded enough to cause this, too.

Peter

Thank you for your reply Peter.

In my case, I also let the fueling stop when the pump "pops" to stop. I do not top off.

I suppose the pump I used could have allowed excess fuel to enter my tank, although I've used this particular Chevron before and have not had this issue before.

The temperature was approximately 55 degrees celcius at the pump, but in my garage it was probably close to 60. Not much of a difference. But I can see what you mean if the gas expanded or contracted.

I'll see if the noise happens again. Hopefully it was just a fluke!

My friend at work told me the sound of the gas could have been due to excess pressure built up against a full fuel tank if I drove the car hard after getting it filled.

I do recall driving my car WOT a few times after getting it full on the way home (something i usually do not do...hehehehe).

Does anyone know if there is some sort of "pressure regulator" for the fuel tank...something like a purge valve to let excessive pressure out of the tank?

And is it possible to build up pressure driving a car hard in a short period of time? Maybe the tank was REALLY full this time around and the sound I heard was indeed the tank equalizing pressure......

This is completely hypothetical, but it's the only thing that makes sense to me now. I hope this is on the right track.