I HAVE A BLACK 2000 F 150 5.4 TRITON QUAD CAB 4X4 LIKE NEW 170K MI. WHEN TRUCK IS COLD, IT HAS A TAPPING THAT IS FAIRLY NOTICEABLE. ALTHOUGH WHEN WARMED UP IS ALMOST SILENT. iN RESEARCHING, IT SOULDS LIKE IT MIGHT BE WHAT IS CALLED PISTON SLAP. IF THIS IS THE CASE HAS ANYONE HAD ANY SUCESS WITH DIFFERENT OIL WEIGHTS OR ADDITIVES OR OTHER? OTHER IDEAS ON WHAT THE TAPPING COULD BE? WOULD SELL THE TRUCK FOR $7825 IF ANYONE IS INTERESTED. THANKS BREEZE@UDATA.COM OHIO

Well, are you using a fram oil filter? They have poor anti-drainback vavles and let the oil drain down from the gallies back into the pan so each time you start it, there is a lack of oil for about 3 to 5 seconds. Also if you are using thick oil it will do the same thing, you should be using 5w-30. Now on my chevy, i used to use fram filters, and i had lifter knock like your 00 f150. Now i switch to wix filters, and that took most of it away, but not all. When i changed the oil, i replaced a quart of oil with marvels mystery oil. Now marvels mystery oil has a wintergreen oil base, and relay's on hydrocarbons to clean it out. Now change you oil in about a 1000 miles and you motor will be cleaned out. MMO is the best stuff i have ever used, its nice beause its a base of oil and its not a solvent.

thanks for your reply
It is what I thought, piston slap. Has anyone been successful in quieting the symtoms without rebuilding top end or replacing the engine? thanks again