My truck only has 70K miles on it, I have an automatic trans, when i really get on it (around 3,500-4,000 RPM's) I hear this really horrible tapping sound just before it shifts into the next gear. It only does it at WOT. Not under normal driving (like 2,000-3,000 RPM shifts)

Anyone have any idea what it is?

This truck has been babyed its entire life, Ive run full syn in it sense the day i got it, and everything ford recommends i do at the correct miles. (flushes, filters, ect..)

 

is it coming from the engine or transmission

 

Engine, sorry. Nothing hitting on the shroud or anything like that, Its internally.

 

might be a small exhaust leak. ive got one that only shows up at higher rpm under load.

 

sounds like pinging to me. check your plugs and timing. could also be some bad fuel. just an idea....

 

do you hear this through the exhaust at all? if so this may possibly be a weak valve spring on either the intake or exhaust port. had this problem on a past 460, low to mid range powerband under load about 2000-3000 rpm. problem arose after a few nights of high revin, wheeling in the snow.