About a year ago, my truck wouldn't start. Tow truck driver hit my gas tank with a hammer - truck started right up. Told me to replace the fuel pump. When I went to start the truck a few days later, the fuel pump didn't make its usual sound when I turned the key (anyone who has a 96 K1500 should def. know what I'm talking about - it's pretty loud). I dropped the tank and replaced the entire assembly - pump, sending assmly, hoses, everything.

But just since about a month ago, my fuel pump is so loud that is drowns out my dual straights. It is SCREAMING loud. The lady taking my money at the toll plaza even asked me "does it really sound like that ALL the time?"

It makes the normal fuel pump sound, but about 5 times as loud.

The only other thing is that I threw a check engine code of "too lean" about a week ago. I ignored it and the light went off. Thought maybe I had a batch of bad gasoline. The noise is still there, though.

Any ideas? Should I replace the pump again?

Thanks!

Forgot to post that this is a 1996 K1500 with a 5.7L 350 and automatic trans.

The noise can be heard ANY time the truck is on, not just at startup like usual. It never goes away, unless the key is off. I'm not exagerating when I say that it can be heard from across the street.

Had a 91 fuel pump crud out on me awhile back, before I upgraded to my 92. I went out and bought the parts, figured I could do it myself, well to make a long story short I gave up. Had it towed to a local shop and the guy didn't want to install the parts I had because they werent GM parts. I asked why and he told me the aftermarket pump I had won't give the correct pressure and the engine would run lean. I had over 200,000 on the first pump and he told me that if wanted the same durability to take my parts back and get the GM parts. BS? maybe - maybe not, I bought cheap parts because I had plans on selling it at that time and didn't want to spend the money on genuine GM. Since I don't like screwing people I went got the good parts.

Unfortunately I got rid if that truck just after I had it fixed but for the time I had driven it it definitely had more power with the new GM pump. Can't give you much info on the noise, my C1500 was relatively quiet, only heard it with the ignition on but the motor off.

Sounds like you need to replace the pump again.
What brand did you use? I've heard Walbro are loud.
Only use AC Delco/Delphi, I've had bad luck with Carter and others not lasting.
Also while you are there, look closely at the pins in the connector on top of the tank. I had a friend who would get his going by hitting the tank then he payed to replace his pump twice and it was the burned pins in the connector.
Bob B

Thank you both for the help -

It looks like i'll be replacing the pump based on what you've said.

I might go ahead and replace the fuel filter first just in case its clogged up.
Taking a 12 year old filter off will be a pain since the fuel lines are so rusty, but not nearly as much as relacing the fuel pump assembly was. Think its worth a shot?

Thanks again!

The filter is a definite must, I change mine every tune-up, on my 92 that everye 30,000 miles or so. The wifes minivan has that 100,000 motor in it, so I change the filters on it every 3rd or 4th oil change.

I chickened out on changing the pump on my 91, it had a camper shell on the bed, not impossible but made removing the bed more of a PITA. I tried dropping the tank, of course the pump went out just after filling the tank, trying to syphon the tank and I finally just gave up and took it in. Kinda glad I did, the mech really pointed me in the right direction.

Good luck and let us know how made out.

So i changed the fuel filter...was a PITA since the lines are full of rust, but overall not a big deal.
When I was changing the filter I noticed that the old filter looked pretty good for being 12 yrs old...so i think what happened is that I changed the filter when I replaced the fuel pump. Either way, new GM filter is on...can't hurt. It only cost $28 from the dealer, so I'll just leave it on.

As for the noise, it didn't make much of a difference at all. I think I'll probably still end up replacing the after market fuel pump that I put on. That is a HUGE PITA but what are ya gonna do?

Thanks for all of the help as usual!