2006 4.0 Piston Replacement

[JKP]

I do have a very very minor either piston slap or sticky lifter for the first 30 seconds of starting the engine cold. Need to look into that more. Nothing I'm too concerned about though.

If you start the engine, let it run for several seconds, turn it off, wait a min or so, a sticky lifter will pump up from the oil pressure and be quiet when restarted.

If so, run some HM oil or the new Restore and Protect in it to clean up the lifters.

 

[topfuel83]

If you start the engine, let it run for several seconds, turn it off, wait a min or so, a sticky lifter will pump up from the oil pressure and be quiet when restarted.

If so, run some HM oil or the new Restore and Protect in it to clean up the lifters.

I'm actually going to try some restore and protect anyways. Before I owned the Jeep there was definitely neglect on oil changes. I think that's what got the pistons knocking in the first place from gummed up rings. There is a lot of varnish inside the engine. Before the refresh I ran a quart of Marvel Mystery Oil through it. Looking forward to seeing how restore and protect works!

 

[JKP]

Let us know how it works. I've seen some videos on it, and it seems to clean the engines up nicely.

 

[User4574]

Thanks for updating your results.

Any reason other than choice for the moly top ring? Saw from somewhere in my searches it was not advised without honing, others say run it, others say steel is fine.

 

[topfuel83]

Thanks for updating your results.

Any reason other than choice for the moly top ring? Saw from somewhere in my searches it was not advised without honing, others say run it, others say steel is fine.

Everything I read said the honing for a moly top ring was a finer smoother finish hone than cast steel. Since I wasn't going to hone anyways, and the cylinder wall already had a smoother finish from the factory rings (cross hatching still visible), I felt moly was a better choice to help seat the new rings. The machine shop I used for the pistons and head also suggested a moly top ring if I wasn't going to hone.

 

[GoldenGorilla]

Nice to see that's worked well for you