MaverickZ71

Ok, I'll bite. V-12 what? Aircraft or marine engine?

Costs a lot to drive a lot these days. Those big games are fun.

The AFM gods smile on some folks. And IMO, the highway miles help. His does 2 hrs a day on the highway. Ours does an hour a day idling in town on errands, etc., which is twice as hard on everything.

. But then again, I never really had to think about such things on any prior vehicles. Thanks again, GM. . Ha

Thanks again, Grump. I'm trying to figure out what to do with our 09 Silverado 5.3L with 106k miles. It had the high/low oil pressure DTC's [on some of my last Shell GasTruck 5W-30 and a new (post e-core) AC Delco PF-48, only a month into that oil change] on a trip when it suddenly got -22F last winter. An oil and filter change and new GM oil pressure sensor and screen was the fix. Since then, I've learned about a GM TSB of sorts--it says that trouble code may be caused by a PF-48 becoming clogged, and to use a 'higher capacity' (?) AC Delco Ultraguard UPF-48R if that happens. Those UPF filters are only available to me online, and I prefer to make such purchases in person. Likewise, Purolators interest me, but the nearest Advance Auto Parts store is 100 miles away. Locally available here are the regular AC Delco and new Fram FE (Synthetic Endurance, made by Champ, similar to the AMSoil and Royal Purple filters) oil filters at Wal-Mart, and the Microgard/Wix/XP line of oil filters at several O'Reilly Auto Parts. This 09 Silverado has the AFM turned off, and has lifter noise on startup, especially when cold, since 7k miles, when a 'tight' Fram Ultra oil filter was used only once. It is currently running a 'loose' Wix XP, and the lifter noise is quieter than it has been in years, hot or cold (!) I only use Dexos1Gen3 rated oil and do 4k mile changes since the lifter noise began, as the GM recommended (back then) conventional oil and OLM indicated 7k oil changes are what caused the AFM troubles in the first place. Some GM techs on here have advocated switching to the PF-63 sized oil filters, as that is what the newer GM truck V8s mostly use. Those have higher capacity due to being about 1.5 inches taller, and the bypass valve pressures have been increased from 12 psi to 22+ psi. I am very interested in using the larger size (PF-63 equivalent), but am not sure about the doubled bypass pressure on the older pickup. What do you (and any other readers) think about the bypass pressure increase? Thanks for your insight!

My lengthy response to GB was lost. Retyped below.

Hey Grump, Thought I remembered you were a Purolator fan. And I know you research the hell out of oil and filters. Wondering about your scientific rationale on Pure Ones on SUV Dizzy, but Fram Ultras on Silverado Pepper? Also your thoughts on the Purolator Boss? Have you noticed any changes in your Purolators since Mann+Hummel bought them and Wix? Thanks!

Pickup Truck song

SUDDENLY?? Fer Christsakes, there's been nothing but AFM/DFM lifter failures since 2007! WITH GM, THE MORE THINGS CHANGE, THE MORE THINGS STAY THE SAME!

My kind of gal.

Dunno. I googled it before I posted that. Pennzoil used to shout "Ferrari specs us!", but their website no longer says it, that I can see. And Luigi in Maranello hasn't rang me back yet.

Interesting. Ferrari was also recommending Pennzoil Ultra Platinum.

Why 2700 mi changes on a T-Rex, with different oil each time? Problems?

IN SOPUS WE TRUST.

Looks kinda like the infamous DOD/AFM/DFM oil usage problem.