Ok last monday when i went to put fuel to my truck i notice that air came out of the gas tank, kind of like when you open a coke slowly. Also during the same week the truck has developed this noise which sounds as if there was no oil for the powersteering. But its barely noticeable unless you pay attention. Is this enough to take it to the mechanic? Don't want to break down on the road, any tips would be really apreciate, thank you?

Best to vent the cap.

This has been discussed many times. Do not vent the cap, it is NOT best. Vacuum is normal when you remove the cap. It is that way for a reason.

It's doubtful that the two issues are related. Cap noise is normal, (2X Torque454)
your other sound may need more checking; not enough info. Is your PS fluid original, low, had additives, ever leaked...? When does it make the PS sound; cold, hot, turning, all the time, when the radio's off (J/K)?

This has been discussed many times. Do not vent the cap, it is NOT best. Vacuum is normal when you remove the cap. It is that way for a reason.

Why is vacuum on the tank not the best?

Where does the vacuum come from?

Not being a wise ass just want to know.

A lot of people think that it was designed to have a vacuum (which is
caused when fuel is pulled out by the lift pump, with the cap holding a certain
amount of vacuum) to lessen fuel foaming. I disagree, foaming would be less
in my opinion if it were under pressure.
When I put a locking cap on mine over 2 years ago, I couldn't find a
"diesel" cap, I used a gasser.....first time I opened it, had a huge vacuum,
I was worried about it, so I removed the O-ring from the cap. I get no
whoosh when I open min, and I know the LP is not pulling against a vacuum.

It's doubtful that the two issues are related. Cap noise is normal, (2X Torque454)
your other sound may need more checking; not enough info. Is your PS fluid original, low, had additives, ever leaked...? When does it make the PS sound; cold, hot, turning, all the time, when the radio's off (J/K)?


The only thing i have change on this truck has been engine oil. I purchased the truck just over a year ago. No leaks, no additives have been used. Noise starts as soon as the engine starts, harder i step on the gas the noisier it gets, i was thinking it was something like a pully, belt, fan, alternator, anything that rotates.

A lot of people think that it was designed to have a vacuum (which is
caused when fuel is pulled out by the lift pump, with the cap holding a certain
amount of vacuum) to lessen fuel foaming. I disagree, foaming would be less
in my opinion if it were under pressure.
When I put a locking cap on mine over 2 years ago, I couldn't find a
"diesel" cap, I used a gasser.....first time I opened it, had a huge vacuum,
I was worried about it, so I removed the O-ring from the cap. I get no
whoosh when I open min, and I know the LP is not pulling against a vacuum.

Every 6.5 truck has some vacuum if the cap is working right. There should not be excessive vacuum but there should be some. You dont want dirt or moisture entering the tank, if it was open to air humidity and dirty air would enter the tank and contaminate the fuel. A cap exposed not sealed may also get rainwater or water from washing your truck into the tank. I do believe it helps with foaming too. Pressure or vacuum either one would probably help.