Ok so don't know if its a problem or what could be causeing it if it is. But when I start my truck there is a good tapping sound. Now if I let it go through its initial high idle and let the rpms die down the tap goes away. Don't know where its coming from in the engine bay, but anyone got any ideas if this a major problem waiting to happen?

 

Sounds like lifter tap to me. I rebuilt my motor and it did it on the first start up. Short of replacing all the lifters and hoping it goes away, which it probably wont, there's nothing you can really do. It isn't really an issue, almost every 4.6 and 5.4 I've seen does it, I just let it idle down and wait for the ticking to pretty much go away before I drive off. I find using 5w-20 instead of 5w-30 helps a little with the noise.

 

Yea when I did my first oil change with it I put in 5/20. Figured it was lifter tap. Now I wait for it to go away before I drive just didn't know if it was a major problem.

 

I think every ford engine has a problem with tapping or sticking valves. Ive got a tap in my 5.8. It is what it is. My neighbor told me what his dad told him.

Fix it
I dont know what it is
Then drive til it breaks, then youll know

 

It's not like a 5.8 though where valves need to be adjusted. It's a totally different design. It's more common to see a 4.6 or 5.4 motor that taps than one that doesn't.

 

Yeah i know that. Just saying, i havent heard any ford motor with a good chunk of mileage that doesnt tap, whine, etc.

 

Now I've got all kinds if taps Haha. Lifters manifolds hell my feet on the floor.

 

Its hard tracking noises down. I would never make it as a mechanic.

 

On the driver side in the engine bay check down where the EGR tube attaches to the header. Thats what was wrong with mine and your issue sounds similar.

 

Ok ill look I had to replace the vac lines going to the dpfe? Couple weeks ago maybe I jostled something loose doing that.