TWANKYDEUCE

iTrader: (1)

earlier today I got out of my truck while it was still running and I noticed a high pitched whine coming from the gas tank area. So I turn the truck off and it stops, and I turn the key to ON to hear the fuel pump then I started it. The fuel pump isnt as high pitched as the whine it makes when the truck is on. Anybody have any ideas?

Mort

When you turn the key to on the fuel pump only comes on for a couple of seconds and it is running at battery voltage (12v). When you start the truck the fuel pump has time to come up to full speed and it is running at alternator voltage (14+v) so it must be running faster and thus the higher pitched whine.

Sound good?

TWANKYDEUCE

iTrader: (1)

makes sense, but I never noticed it before. Just seems alot louder than it should be

Mort

I think I have read that the fuel pumps tend to get a little noisy with age. Maybe it is a sign that your fuel pump is wearing out. Sorry I don't really know for sure. Does it make the same sound when the tank is full? Could it be a problem with the little tub it sits in? If you got a bad tank of gas full of dirt or water then perhaps the filter screen on the pump intake is gummed up reducing flow to the pump making it work harder.

Maybe someone else has had this problem and can shed more light on it. It almost sounds like it might be worth it to drop the tank and check it out.

You might get more response if you post this under Engine and Performance or General Discussion.

BoneDaddy

Mine started making the same noise about 6 months ago. A couple weeks ago the truck would stutter at wide open throttle at about 4k rpm when the fuel was below 1/2 tank.
I bought a brand new AC Delco pump on ebay for $144, pulled the bed, and installed it last week. Now I'm whine free and back to full power.
If you can live with the noise I'd let it ride for a while if you are strapped for $$ or time. Mine went for a while making that noise before I started noticing a performance loss.

chrias

Your pump is on it's way out. I went about 5 months before it finally died on me last Saturday night and had to get it towed home. Luckily I bought one on eBay and it arrived last week. Had the truck running the next day and all the power is back.

01Blue4.8

mine started whining awhile back, but has since calmed down.

LS1TRUCKGUY

iTrader: (7)

Mine Was Screaming At Me When I Bought The Truck About A Year Ago. Lasted Until 2 Weeks Ago When It Died In Front Of My House. New Fuel Pump Now Purrs Like A Kitten.