Buzzing from rear of k5

[stipton]

Hey guys I just noticed that my k5 has a buzzing sound near the rear of the truck while running, It also does the noise when you turn the ignition on. It sound like it coming from the fuel tank. So my though was that it is the fuel pump because i believe they are inside the tank on 87s.After reading a few post i am pretty sure it is the fuel pump or fuel pump relay. I only say the relay because a post said that if your not getting 5psi of oil pressure the truck will try to start longer and mine sort of does that. I just want to see what some of the vets thoughts are as i am new to the k5 world. Thank you for the responses ahead of time.

 

[sweetk30]

fuel pump. some are noisey and or if old and start making noise be ready for pump swap .

relay is pass side firewall roundish big relay up near top of firewall 2 little 7mm screws hold its bracket on . and little red pig tail wire off wiring of it for 12 direct power up testing in trouble shoot testing.

 

[Russell]

yup, fuel pump!

 

[rampage]

It's your pump 100%. Mine made that noise and when I took it out and had it on the bench I connected power to it and it vibrated really bad. I'm guessing it's a bearing inside the pump motor that wears out and makes it unbalanced.

 

[Jessie James]

Yup, fuel pump, probably on it's way out. My 1991 doesn't make any noise at all, but my 1990 did right before I had to replace it...

 

[Fordum]

I also agree about the fuel pump, but if you want to verify it, open the gas cap, and put your ear next to it while someone turns on the key.
Should be much louder there.

 

[munepit]

I installed a brand new one last yr. It has made noise from day one. Dont worry about it.

 

[stipton]

Alright well thank you gentlemen. I love this website.