i have a 2004 4.6 my enging is making a tapping noise. sounds like its coming from the intake manifold??? its to hard to tell. there is no noise under the engine just on top. ill post a video once i find my camera. what could it be?

 

It could be the lifters tapping. If you have a long-handled screwdriver, place the blade on the engine and place your ear on the handle and you will be able to hear the noise thru the handle. This should help you narrow down where the noise is coming from. Or you could go to RiteAid or Walgreens and buy a stethoscope.

 

here is a video. i did the screwdriver thing and the only spot it tapd was on the alt. ????????????

how about this cam phaser thing?

 

Cam phasers are only on the 5.4 3 valve models. Have you tried this without the belt (briefly)?

 

This article supersedes TSB 05-15-8 to update the Service Procedure. ISSUE:

Some vehicles equipped with a 4.6L 3-valve or 5.4L 3-valve engine may exhibit a ticking and/or knocking noise after reaching normal operating temperature. The noise may be described as "ticks", "taps", "knocks", or "thumps". In some cases the noise may be a normal characteristic of these engines. In other cases the noise may require further investigation. Sorting out and defining the noise as reported by the customer is important to successfully diagnose and/or repair the condition.

i think my truck has a 4.6 2-valve right?

 

That sounds more like the alt. pulley/fan hitting something plastic or metal. Kind of like sticking something into a fan blade and it slightly hitting it. Check for debris around the fan pulley areas; of course with the engine off. I listened to it again it may be the alt. bearings. Take the belt off check for play on the alt. pulley. You can also, as suggested, run the engine a few minutes with the belt off and see if the noise is gone. If it is you know it's not valve train noise. Good luck and keep us posted.

 

After hearing the noise, I don't think it is the lifters.
If the noise is coming from the alternator, as you say, then I would suspect bad bearings in the pulley wheel, perhaps.

 

ill work on it today for a little. but thanks for all of the help!

 

Let us know what you found and I agree it does sound like the alt. bearings the more I listen to it.

 

Take the belt off and start the truck see if the noise goes away.