2001 F150 5.4 142,000 miles. When the engine is cold there is an intermitent clicking noise. It will change intensity and will come and go until the engine gets to normal temp. Once warmed up it never does it. Originally the noise came from the left bank, now seems to come from 2 or 3 locations. Sounds like a hydraulic lifter that wont stay pumped up, but I didnt think overhead cams had lifters. Any ideas

 

Check every exhaust manifold stud on both sides. I'll bet one is rusted and broken and causing the noise cold. Exhaust leak.

 

had already checked for anything external. This sound is definetly coming from within the engine.

 

i think that it is piston slap! It has alot of miles on it, and when it is cold the pistons contract- slapping when it is run until it gets warm enough and the slap goes away! If it was lifters or something it would most likely do it all the time, not just when it is cold. I would check the rings, pistons, and cylinders for excesive wear. It may be one, or all three of them. If it is a daily driver i might worry about it a little, but if it isnt than because of how many miles it has- i wouldnt even bother with it. If so than just let it warm up a bit before you drive it to allow for the engine to heat up, and it should be fine.

 

no worries specs for piston slap when cold on this vehicle is normal don't even worry about it

 

my 04 new body does the same thing not a big deal