Engine lifter noise (mileage, purchase, 2000, Expedition)

[Bigg Mann]

My recently purchased 2000 Expedition with 148,000 miles and 5.4 motor has a little liffter rattle. Does not do it all the time or I just don't hear it.

My mechanic says these 5.4's were known for this and I suggested putting Lucas oil treatment in and he said no that would do more harm than good.

It calls for 5w 20 oil and my brother suggested upping oil to synthetic 10w 30.

Any ideas?

[Lux Hauler]

At that mileage it would help to put something a little thicker in there. Start with the 10-30 then maybe try 10-40. I wouldn't waste money on synthetic, it's not going to help much in the noise department.