Originally Posted by clinebarger
Yes, They did. But it just prolonged the inevitable. The early designs slipped into the oil pump quite easily with a good lube, The later ones take some force.
My 05 4.8 just started ticking after the last oil change. I went from Pennzoil high mileage conventional and a cheap ecoguard filter to Quaker state full synthetic high mileage and a fram ultra. It was silent before other than piston slap on extremely cold starts. As soon as I started it after the oil change it had a discreet but noticeable lifter tap. Piston slap also now happens every cold start. I've never had an oil change make such a noticeable difference before.
The tap occasionally gets a bit quieter but it's always there now. I've gone 600 miles since the oil change a month ago. I'm thinking about switching it to some Castrol edge 10w30 I have in the garage and see if that changes it, but I'm worried about the oil pump pickup o ring. If this was the problem would it not affect the oil pressure? Oil pressure looks to be as good as a new engine.
The weird thing is a couple of years ago this truck started to develop steadily lower oil pressure about 2k miles into an oil change and as soon as it was changed it went back up. This lasted for about 3 oil changes of 3k each and then the problem never came back.
It currently has 195k miles and 8400 engine hours, since 120k it's had conventional changed every 3-5k miles. Before that, unknown. It was the bosses truck and he usually drives and the dash says to change the oil.