Just bought 2000 Ranger with 123k miles and lifter noise. I have hooked up mechanical guage and the oil pressure starts at 50 psi at idl. After running for half an hour I'm at 14psi at idle and 35psi@2500rmp. Fresh 5w30 with filter.

What is the oil pressure supposed to be at operating temp at idle?

What would be my next step in troubleshooting process?

 

haynes manual says for a 3.0l it should be 40 - 60 PSI @ 2500 RPM, for a 2.3l and 4.0L it should be 40 - 60 PSI @ 2000 RPM.

 

2002 3.0 4 cyl. I noticed my oil pressure guage had bottomed out at 60 MPH. I am not sure how long this lasted. Pulled over and could hear a loud tapping from topr of engine near front. I install new filter and oil and put in Lucas. Still tapping. Any answers for me?

 

Its not a valve tapping, but could be a lifter or rocker
No crystal ball here

 

Could just be no oil pressure to put oil in the top end !

 

2002 3.0 4 cyl.? ... Anyway, Have you considered the Cam Sync? The way you describe it happened kind of makes me go that way.

 

I had the truck at precision tune the day before this event. There was a coolant leak. They replaced intake manifold gasket, valve cover gaskets,gooseneck gasket and the fan clutch. I approached them concerning this and they have yet to get back to me. I feel that while the top end was open, something (maybe gunk) dislodged and was sucked over the oil pump screen. Whatever the situation was has left me with normal pressure? AND a tapping in the top end

 

There's a chance the mechanic did not get a rocker tightened down properly after reinstalling the lower intake. Or.. your lifters, rockers and pushrods are just getting too worn. Happens. Unless you can prove it is something the mechanic did, I doubt they will cooperate much. You haven't mentioned whether you checked your oil, or what weight you are using. If you had a coolant leak, depending where it was at, coolant could have gotten into the oil pan and mixed with the oil... especially if the mechanic didn't drain the coolant out enough to change the lower intake gasket. I know, crazy right? You wouldn't believe what I've seen though. lol