Hmmm. My 03 4.6 Expy all of a sudden is making an audible tapping sound, seems like I can hear it from the right (psgr) side. Truck has about 74K miles. I regularly change my oil (RP), keep the engine clean. I have it tuned to 93 octane with an xcal II. Efans and UD pullies.

One change in truck usage though - a few weeks back i got a company car so I no longer drive the truck. My son drives it to and from his part time job and county college, probably 3 miles each way, a few times a week. Truck doesn't see any real highway miles any more.

Wondering if it is not being driven enough to burn out carbon and water vapor?

Any thoughts? Im thinking a valve is tapping. Just wondering what would cause the tap?

Thanks.

 

check your exhaust manifold studs. I've got the same thing on my driver side.

 

I'm pretty sure this is a valve tap. Just trying to figure out why it would show up on an engine that is well cared for with only 75K miles on it. And, how do i get rid of it other than taking it to Mr. BadWrench?