Each of the past two mornings I've heard a gurgling coming from the fuel tank after returning home from dropping the old woman at work and shutting the engine down. It's been below 20F degrees both mornings, relative humidity right at 10%, and the engine hasn't reached normal operating temperature before shutdown. (I usually give it five minutes of warmup time, but I've been slow and stupid at 4AM these past couple of mornings.) The gurgling stops of its own accord after several seconds.

I didn't perceive any pressure or vacuum being relieved when I opened the fuel filler cap. The tank is nearly full, gauge still above the F with only about 20 miles of driving since fill-up.

Later in the day yesterday, after the temperature was above freezing and after the engine was a normal operating temperature I didn't notice any sound at all from the fuel tank after shutting down.

Anybody got any insight into this?

 

I've personally been noticing mine is sloshing anytime I touch the truck. No idea if it might be related, but I figgered I'd throw that out there.

 

Icing in the fuel return maybe??

 

No return line on these trucks.

I would put a gauge on it, and see how fast pressure bleeds off at shut down, the supposition that maybe its gas draining back into the tank sounds perfectly reasonable.

 

My tank does the same gurgling thing, but my fuel pressure regulator (i think) is shot because the gas drains back into the tank while it sits so i gotta prime the engine before i start it, dont know if thats what yours is or not.

 

It's just our trucks telling us they want more fuel.

 

Sorry was thinking about that vent line.

 

Plausible certainly, but as the guy who'll get to drop the fuel tank and in the cold of winter it doesn't sound so very reasonable to me!

Until I actually hauled out the FSM after reading your reply I hadn't noticed that on page 14-6 Fig. 3 (filter/regulator) calls out "4 - EXCESS FUEL BACK TO TANK".

Guess I'm renting a fuel pressure gauge one day real soon, fairly certain that I'm going to find that the check valve in the filter/regulator is failed. Damdamdamdamdamdamdamdam! I've got a brand new in-the-box Auto Meter fuel pressure gauge destined for installation in my pillar pod... in Vegas until I get my happy backside down there to retrieve our household goodies. Murphy's Law or some corollary thereof strikes again.

 

Aw shucks. With the temperature being 45F and the truck nice and warm, I shut 'er down and it's quiet as a mouse in the tank again.

Very interesting. But not in a good way.