Strange ticking only at idle. not sure if its a lifter or what any ideas on how to diagnose?
99-4.6-2wd
appreciate the help!

 

First thing I would check is the passenger side exhaust manifold for broken studs
Do a search for "Triton engine noise/knock/tick"
Ignore all the 2004 and later hits as they are mostly
cam phazer related
Welcome to the forum!

edit....check for loose spark plugs

 

I have checked studs and spark plugs and all is tight and good.the noise is strange because it only happens every now and again and only low rpms. in my experience a lifter tick doesnt come and go as it pleases.

 

It may be that the lifter is just starting to go and is noticeable only at idle. Once throttle is increased and oil pressure rises, the lifter may hold enough to pick up the slack. I have a bad lifter in 98' It started out only noticeable when the engine was cold. After a few minutes (as it warmed up) the ticking suddenly stopped. 2 years latter it ticks all the time especially under load. I have a new one ready to install once I find the time to do so. The follower may be bad also and may need replacing to, once I get in there? Looks like a PITA to remove the valve cover, hope I can get around the AC lines without disconnecting them. It just has to make it through the summer because I have newer 03' 5.4L engine to drop in it's place.

 

I had a similar thing happen to my 2001 f-150. Turns out it was the timing chain tensioner. 247k miles she runs like a new truck

 

Did you install an entirely new tensioning system while you had the front cover off?