strange sound from inside engine, while it's off!

[Jerseydevil]

the other day I was standing next to the truck with the hood open trying to fgure out why it don't run, when i noticed what I can only describe as the sound of a tiny ballon salesman operating somewhere within my engine. You know the sound that is made when he fills a helium ballon from the tank. Some of you who attend rock concerts know the sound but it is from a different kind of tank It was barely audible, but there it was and I wasnt dreamng. It seemed to come up through the carb. I figure it might be related to the vac advance but I don't know. Feel free to thrugh your 2 cents in.

 

[Viperwolf1]

Float needle opening to let fuel into the bowl?

 

[Jerseydevil]

Hmmm... Could be. Makes more sense than my little man theory.

 

[TBS-POPS]

Compression pushing back through the intake valves and hissing through the carb.

 

[Pedestrian]

Fuel dripping into a hot intake and hissing as it vaporizes

 

[Pedestrian]

Disregard previous post, didn't catch the part about it not starting. Therefore not hot.

 

[crankman]

Check your PCV valve make sure your engine can breathe

 

[DRBRONCO69]

Vacuum leak

 

[Jerseydevil]

To be clear, the sound occoured at about 5 second intrvals. On for about 3 seconds, off for about 5. Very steady. I stood over it and listened for about 3minutes and it did it the while time.

 

[DRBRONCO69]

Disregard the vacuum leak statement above as well. I did not realize the truck was not running while you hear this noise.

 

[Justafordguy]

Had the engine been running before you heard this noise? What the engine hot?

 

[bmc69]

oil pump left running after engine turned off?
.
.

.
..maybe not.

 

[Viperwolf1]

oil pump left running after engine turned off?
.
.

.
..maybe not.

Only if he has one of those spring wound oil pump shafts.

 

[RangerRob]

How about fuel expansion from your gas tank heating up and forcing pressure through the pump and carb or evap system if it is still in place? You could take off your gas cap (to relieve the pressure) when it is happening and see if it stops.

 

[Jerseydevil]

ok, heres an update. I now think Viperwolf is right, or atleastclosest to being right. I crankedit over a few times tonight and when I went around to the engine compartment I heard it again. Plus i also think I heard a drip sound. Great!

 

[Jerseydevil]

ok, heres an update. I now think Viperwolf is right, or at least closest to being right. I cranked it over a few times tonight (yes, I pumped the pedal afew times) and when I went around to the engine compartment I heard it again. Plus i also think I heard a drip sound. Great!

 

[Viperwolf1]

ok, heres an update. I now think Viperwolf is right, or at least closest to being right.

Which, the spring wound oil pump shaft or the carb needle?