XQIZT

I have a tapping that sounds something like valve noise. But I'm not entirely sure...its steady (when it happens) and speeds or slows based on RPM. It sounded like a loose exhaust shield, but its not.

And I'm not sure if this is related or not, but today as i was driving at about 50 MPH after the engine was warmed up, my oil pressure was fluctuating between 42 and 63PSI...then it would hold at 42...then slowly rise to 60ish...then back down. Thoughts? Where do I even start on this?

86K miles. Last oil change was about 3000 miles ago but I am using Mobil1 Synthetic.

vetteblack

I'd say oil pressure will vary with rpm's. It should be consistant when the rpm's are consistant.

XQIZT

Thats exactly my point. At a constant 50mph, no a/c on, constant RPM and my oil pressure was jumping up and down. Oil temp was constant...about 20* more than the coolant.

coupeguy2001

your oil pressure sender might be no good, get another, and your oil pressure will be constant unless there is an engine malfunction.
To check it, remove your oil temp sender with the engine off and cold, screw in a mechanical gauge, tape it to the hood so you can read it while driving. cushion it with a rag.
If it fluctuates, you got a problem with your cam/oil pump distributor drive gear.
Check it soon before you get stranded

JAKE

When this happened to a couple of engines I had both times it turned out to be a worn oil pump drive gear; the one attached to the distributor (in the case of a L98) and the gear on the stub shaft (LT1).

I attribute both instances to me running a HP oil pump.

Jake