i'm working on a 2001 f150 5.4 4wd. I replaced the headgaskets and reinstalled the heads, guides, tensioners. I timed the motor following the directions, and everything seems good to go ( i slowly rotated the motor by hand about 50 times). I'm having an issue with the passenger side chain going slack every few rotations, but the driver side is nice and firm. it has the metal tensioners in it, and they appear to be working right.

I've read that they work off of oil pressure when it builds up. is there any way to check to see if they are faulty before i put the cover back on and finish putting the motor back together?

 

I think what you are seeing is simply the slack between 'ratchet notches' on the ratcheting tensioners. Oil pressure should take that slack out when it builds up, and pushes the tensioner arm out 'enough' for the ratcheting tensioner to catch the next notch.


The reverse torque the cam lobes/valve springs place on chains is pretty significant - and leaves all the slack on one side of the chain. That's normal.