After running low on oil very briefly, my 2001 F-150 has an unusual engine noise.

If you drive at about 65 mph and back off on the throttle, there's a ticking sound that sounds like engine ping.

The strang this is that the sound comes only when backing off on the throttle at about 65.

There's no noise at idle, cold, accelerating etc. Drive over or under the 65 (3,000 rpms) and it's silent.

I'm thinking a lifter, push rod or a rocker got damaged?

 

Hi and welcome to the forum.

The 5.4 doesn't have pushrods or lifters. It has overhead camshafts with cam followers and lash adjusters.
It is weird that it only does it when decelerating. I wonder if there is a small exhaust leak somewhere causing the noise.

Jimmy

 

Already you've helped.

I was told that the 5.4 valve lash is non-adjustable and that replacement was the only option.

Would you have a link or information to the lash adjusment procedures?

 

They are not adjustable. They are hydralic like a lifter. They take up the lash between the cam follower (like a rocker arm) and the valve.
I have never had one of these engines apart yet, but I am sure that they are similiar to the TurboCoupe T-Bird that I did.
Jimmy