buzzing noise from under cab

I've got a 98 ext cab with a 305 and I have a constant "buzzing" noise which seems to be coming from under the mid section of the truck.

Can't say I've really investigated yet...just pulled through a drive through today and with the side wall I heard it clear as day

weird !

Probably Your Fuel Pump My Brother Has Same Year Its Loud Also Which Is Good I Guess When It Gets Quiet Your In Trouble These Trucks A Notorius For Pump Burning Up Just Replaced Mine Again. Hints Keep 1/4 Tank In It To Keep Pump Submerged And Cool And Change Filter Regularly Good Luck. Ron

aaah...yup, that makes absolute sense.
Yeah, I guessI know it's working

Cheers

If it has gotten louder now, and you notice it when you didnt before, be ready to replace it. Mine got louder for about a week or two before it died...

If it comes to the point that your Truck won't start grab a 2x4 and hit the gas tank from the bottom it might start it has worked on me before and this is real handy to know when your out in the middle of no where or low on money. Good luck! RS

Warnign, with that truck, you need 55 psi of fuel pressure to run and 60 - 65 psi of fuel pressure to start, I just had the same problem with my 97 sierra. It may eventually get to the point where the fuel pump still sounds like its running, but the truck wont start, or like mine did, may just stall for no reason. Watch for it to throw codes for things like bank 1 or 2, or threshold below efficiency level. Its a early warning.