2000 Ford Expedition

Are you sure it is the lifters? They would make noise all of the time. If you hear it when you accelerate, my guess is that you have an exhaust manifold leaking. It is common on the 5.4L. The bolts break allowing exhaust to leak. Let me know if it is a ticking noise you hear.

Joe

I just did the exhaust manifold ford expedition 2000 and it was easy I applied anti rust liquid for 3 days in a row and after that took it out the dealer wants tons of money for this job and my local mechanic wants 500 and up in parts I spend online in amazon/ebay both sides with the new bolts 220 and even with EGR line from the driver side that it was broke too.
it is difficult but if you want to save some money you have to do it I end up with 2 broken bolts and I heat it up with a pluming torch and once it was red I put the 13 mm on top and I hammer it down since is hot make it fit perfect just a little water on top cool off and done take it with a ratchet...one more thing look a the youtube videos before you attempt to do this kind of job train yourself and it will be a perfect results...I probably watched over 50 videos and make your own share your experience...good luck.
fabzionj