Earlier, this year I replaced my Comp Cam flat tappet lifters with some Ford Racing lifters due to a couple of lifters that were weak. I replaced them with new Ford Racing ones, and once again I have I think 2 that are going bad.

It's been that way since day one when I installed the Ford lifters. Though I have managed to isolate the problem to #7, #8 cylinders. Though unsure of which lifter or lifters is/are the problem.

My symptoms are the usual. When cold, and starting the truck, I can hear the constant tapping of a lifter that has lost its prime. Hotter weather helped, but now that its cooler, its more noticeable now than ever. It doesn't do it all the time, but only when the engine seems to come to a complete rest, that depends on where the cam stops, and which lifter is fully depressed with the pushrod nearly or at full lift. I know that the lifter should hold pressure, but should it be dead after only say 4-5 hours? When I pull the driver side valve cover, you can physically see that every roller rocker is in the relaxed state. Something I never noticed with the Comp cam lifters. But once primed, the roller rockers show lift fine, but over the course of 4-? hours, nearly all rockers are back to identical on the relaxed lift. I still have the original Comp cam lifters and after 9 months I still have 3 that are fully primed and take a lot of psi to push the cup in.

My question is whether I should simply purchase NOS Ford tappet lifters that most of all our older trucks came with? I know they were good lifters as my 4.9 still has the OEM ones from 1992. Or should I purchase just another name brand set such as Comp or Lunati or any suggestions.

 

Bump..

Perhaps Isky Lifters

 

Make sure your oil filter has an anti-drain back valve… a filter without one will allow the lifters to make noise for a few seconds after starting.

 

Thanks krooser for chiming in. All I ever run on the 5.0 and 4.9 is the Motorcraft FL1-A oil filter. Even replaced a quart of oil last month with MMO and ran that to see if it would help, but it didn't.