So recently ive been having problems with my truck..

The truck has a rough idle but when i press the gas and drive it, it drives well.
At idle i can hear a SUCKING noise coming from my gas cap, like every 5-6 seconds it will make this sucking noise. My guess was fuel pump? I take the cap off and the sucking noise goes away... Im stumped :( HEELLLPPP please

 

sounds like the gas cap is not sealed all the way and that sucking noise is air being leaked/sucked in?

 

idk but it's pissin me off lol

 

Go to autozone and pick up another gas cap, won't be much at all.

 

If I remember right, you can even get a locking gas cap for under $10.

 

bought a new cap lol... I have 30 more horse powerz :)

 

well the damn sucking noise still exists even with the new gas cap so im eliminating that's as the culprit :( any other ideas why this noise exists?

 

turn the truck on crawl under and look around lol

 

ill go check it out

 

check the filler neck

 

Canister purge valve is stuck open.
Locate the charcoal canister under the hood (drivers side of engine)
Follow the hose from the canister toward the engine , there will be a valve solenoid and then an inline switch.
Remove the solenoid and try to blow through it.If you can , then tap the bottom of it against a block of wood.If you can still blow through it then replace it.

 

oooooooooooo i will look for this, THANKS :)