Well, I am in the process of a teardown right now to inspect for obvious signs related to my vibration problem I was having (per a couple of my other threads). So far I haven't found any bent valves, rods look good, seals and guides show no signs of wear. I was checking the lifters and all of them have a slight amount of play in them except for 2. Those 2 are stiff. I cannot compress them at all by hand, whereas the others will compress I'll say maybe an 1/8". Would this be the sign of a bad lifter? The lifters were new when I did my PI swap, maybe 5000 miles ago or so.

Also, if this is the sign of a bad lifter, will the lifters from my stock NPI heads work in the PI heads, ie. same size, same compression properties, etc? This would really help me out if they would, as I might be able to get the motor buttoned up tonight/tomorrow seeing as how I see nothing else obviously wrong. I did have some valve marks on my passenger side pistons, but only from where I was timing/degreeing the cams with the motor in the car and didn't have it in safe mode when I took the chains off and cam rotated from its fulcrum point. I have inspected each valve and they are not bent and did not have PTV while the motor was running, only from the timing process.

Thanks for the help.

Scott

 

the lash adjusters (lifters) should be compatible from any year 4.6/5.4 2v. If you can't compress those 2 by hand even a little then taht's a bad sign. they're hydraulic so they should be able to compress.

NPI adjusters should be just fine. I'd bet that new ones will help the vibration. You should also be able to use the roller finger followers (rockers).

 

Thanks, that's what I thought, but just wanted some verification from someone with a little more experience than myself. I put those 2 lifters in a vice and slowly bled them down and now they act just fine, but I don't know if I am willing to trust them. The lifters aren't that bad to get to if I had a problem later, but I think I will feel safer using my old ones as replacements.

Scott

 

Sorry, I know they are lash adjusters, but keep calling them lifters, but anyway...

I just went down and tested all of my lash adjusters from the NPI heads and they are all stiff as well. I guess I am stuck to reuse the 2 from my PI heads that were stiff, since I put them in a vice and now they compress slightly like the others. I guess that if I still have problems or it goes away and comes back, the adjusters will be the first thing that is replaced.

Scott

 

All the lash adjusters turned out to be ok. After firing the motor and then having to tear it apart again, I found that even the adjusters that I feared would give me problems were tight so all is well in terms of my lash adjusters.

Scott