Interested in hearing what you guys have to say on this topic. I was reading on another site about running oil other than 5w-20 in these trucks to cut down on VCT ticking and/or dieseling sounds from the 5.4L at low rpms. Apparently, there was a service bulletin years ago stating that owners may elect to use motorcraft 10w-40. I had read folks also used 5w-30 as well. I've run nothing but 5w-20, but found this interesting all the same.

 

I run Motorcraft 5W-20 in mine and have never noticed any of the noises some guys complain about around here. However, I only have about 3000 miles on my rig, so I may not be the best source of information on the VCT issue.

 

I recently changed from Royal Purple 10w 30 and switched to Mobil1 5w 30.

 

Amsoil 5w20 fully synthetic with archoil friction modifier.

 

Motorcraft 5w20 synthetic blend and a Motorcraft fl-820s oil filter for all of its 122k miles of life here. Not one engine complaint.

 

This^^^^

with one exception..............I'm pushing 163k

 

^^This^^ I've had other issues not related to oil and filter.

 

Don't have a 5.4, but I run Mobile 5w-20 extended performance with the Mobil extended performance filter.

 

5w30 and MC filter...no issues although I do think I will switch to synthetic soon

 

Mobil 1 Extended Performance 5w-20 and a Motorcraft fl-820s oil filter...Changed at every 10K.

 

I guess I'm that guy...Mobil1 Full Syn 10w-40 with Motorcraft filter. I was starting to get the VCT shakes with 5w-20 and 5w-30. YMMV, but for me the heavier weight oil raised the oil pressure enough to get the VCT system up and running again.

EDIT: This is probably what you're referring to. Definitely never made it to an official TSB, and not sure if one was ever put out for the 04-08s specifically.




For me, the shaking and real loud noise only happened at operating temp under light throttle. I could confirm with my Gryphon tuner that the variable timing was going wacky. For my next oil change, I'll probably go with 5w40, just so it's not as thick through the winter (cold starts).

 

Motorcraft 5w20 and Motorcraft filter in mine since day one, 10 years now. No issues what's so ever.

 

Motorcraft 5-20 on the 2005 for 135,000 miles and same for the 2011 with 78,000. Never a problem.

 

Mine has a tapping now at times once warmed up at low rpms say 800-1200 at cruise or very light acceleration.... been that way for 5-6k. I'm a little over 104000. I'm going to have it torn down and looked at eventually. It makes me nervous but power seems fine.

 

I just changed my 5-20 to 5-30 and my dieseling and ticking noises went away. I still have a rough idle and a misfire I am chasing. But the motor sounds better.

I have 154K on her.