New to the forum but I have a 00 silverado xcab. I recently just put in a new fuel pump and now when I turn the key to the on possition when the fuel pump is priming up it makes a horrible ratteling type noise that sounds like it starts from the engine compartment and goes all the way back to the fuel tank. The truck is hard to start also. Could this be cause by air getting into the fuel lines somewhere and vibrating the lines along the frame? Any answers would be greatly appreciated.
thanks

Welcome to AF.
What engine and size truck?
Make sure tank has plenty of fuel in it.
Check fuel filter.
How does it run after starting?
To check fuel system you need to get a fuel pressure gauge on it and go threw the complete fuel pressure test.
Hit us with your engine size.
MT

It has the 4.8l engine. There is plenty of gas in it and the fuel filter was changed with the new fuel pump. It runs perfect after it is started.

Airtex fuel pump?
Does it do it with a fuel tank of gas?
Not much of a way air can get in lines unless you have a leaking line or it is sucking air at bottom of fuel pump.
Recheck that fuel filter.
Also check for good 12 volts to fuel pump and good ground.
You need to get a fuel pressure gauge on it and watch and check the fuel pressure when it is making the noise and starting.
Watch for functioning gauge and for around 60 lbs of fuel pressure on start up.
Specs on it is 55/62 lbs of pressure.
Also recheck on the road running and after a 20-30 minute driving.
Let us know what the fuel pressure test shows.
MT

New to the forum but I have a 00 silverado xcab. I recently just put in a new fuel pump and now when I turn the key to the on possition when the fuel pump is priming up it makes a horrible ratteling type noise that sounds like it starts from the engine compartment and goes all the way back to the fuel tank. The truck is hard to start also. Could this be cause by air getting into the fuel lines somewhere and vibrating the lines along the frame? Any answers would be greatly appreciated.
thanks

here's my 2 cents.
get a helper and mech stetoscope. not expensive, like 5 bucks at harborfreight tools. pop the hood open and pinpoint where the noise is coming from.
the only thing that i know that will make a rattling noise - in the engine compartment - when you have the key in prestart position, is some kind of relay. pointing the source of noise at least can narrow it down to something. might be completely irrelevant to the last repair, life happens. esp if you did not have battery terminals off when doing it......:nono: :nono: