I just put a new fuel filter in my 04.5 and now on cold start I have a new sound. When I turn the key and wait for the wait to start light to go out there is a new sound. I popped the hood and the sound is coming from something that is right in front of the coolant overflow bottle. There is a orange electrical connector on one end and the other end has a rubber tube coming off it (vacume line?) It sounds like inside of this device (i wish i new what it is called) there is something spinning and it is not spinning balanced, it is wobbling and making a vibrating noise. If I wait for the start light to go out and do it again the truck sounds normal, but if the truck sits for awhile and I go to start it the noise comes back. My wife drives this truck so it is possible that it has done it for a while and I dont see how it could be connected to the fuel filter. Does anyone have any ideas on what is going on? What is this part? What does it do? I assume the vibrating noise is because it is going bad. Can I fix it? Will The warranty cover it? I guess I am looking for the right direction to proceed from here.

 

That's the vaccum pump. It's normal to hear that sound when you first fire it off or after it sits for a while. Nothing wrong with your truck.

 

Thanks for the reply. Its just that it used to not sound like that. I listed to it with the hood up and I can here it wobble or vibrate and then it smooths out. I am positve it did not have the wobble sound before