gforceman

Why is it when u start your motor. (5.4) when cold its runs like factory new smooth no noise. After warm up. .. noisey and little rough. What gives.?

screw04

Because Ford runs thin oil in these motors, add a pure synthetic stabilizer and she'll quiet up

usmarine3533

I've also heard a lot of guys using 5w-30 and it quieter it down and that Ford only used the 5w-20 for meeting mpg standards

otto457

Search VCT and cam phaser operation. Don't add any additives.

yoop

Im glad to see im not alone. Mine does the same thing, it runs perfect and sounds perf at cold start and after a few minuntes of being ran it does just what ya said. I also notice a little loss in power it seems do you feel this too?

yoop

BTW I have a 2006 fx4 5.4 L and I switched to a 5w-30 on my last change and it did quiet down a bit but can still be heard at times. However I did not use a full synthetic

usmarine3533

I also always add Lucas synthetic with all my oil changes it seems to work well

otto457

Tribologists cringe everywhere at Lucas. If foams terribly (air bubbles are not good for lubrication) and only dilutes the additive pack of the oil as it has no additives. It's been proven to increase wear, but quiets things (because it is a gear oil viscosity equivalent) so people think it is working.

http://web.archive.org/web/201009261...ucas/lucas.htm

screw04

I use it as well, in my tranny as well

Spartan54

I have tried quite a few brands over the course of 90K on my 07 5.4. I settled on Royal Purple. Great stuff and the truck runs best on it. Every 5k--