I am losing oil pressure after the engine warms up. The pressure drops off to zero and I am getting some lifter noise. I have put 20w-50 in with a K&N filter but am still having the problem. It also seems as though the problem is worse when under demand. I am running an aftermarket oil pressure gauge so I know that I am getting the right feedback.
My thought is replace the oil pump. Any thoughts or suggestions would be appreciated.
What engine? please insert year, engine/tranny/Xfer case etc type in your signature (go to My Controls in top right side to insert info in your profile, etc.) for better responses in da future.
Leaking or burning oil (blue smoke from tp)?
Assuming oil level is okay (since you seem to know this stuff well)
check the filter, might be plugged with gunk
drop the oil pan & check da oil pump pickup screen
inspect the pump
... the engine may become starved for oil at higher rpms cause the oil is not returning quickly enough to the crankcase. .. usually severe varnish build-up restricts the oil return holes in the head
Leakage between the oil pickup tube and pump, as well as between the pump and block can also **** air into the pump. It is not unusual to find engines where the pickup tube has fallen completely off, causing a complete loss of oil pres
worse stuff next;
in a high mileage engine, low oil pressure is often due to a combination of worn main & rod bearings & crankshaft journals
if da engine is burning oil, the valve guides & seals are most likely worn, but the rings & cylinders might be bad, too.
a wet compression test and/or leakdown test will tell you if the valve guides or rings and cylinders are worn
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also
Oil Pressure Loss On
Ford 4.9L (300 CID) Engines Built On August 1, 2 And 3, 1983
A small quantity of light E & F trucks and Bronco vehicles may have mismachined camshaft journals which could cause premature bearing wear and subsequent loss of engine oil pressure. Low oil pressure concerns, with or without engine noise, may be a result of this condition on subject vehicles built on the above dates.
To determine if a camshaft is suspect, inspect the journals and lobes for any excessive wear, chatter or unusual pattern on the surface finish. Pay particular attention to the #1 lobe or the 2nd and 3rd bearing journal.
If any of the described conditions exist, replace the camshaft and bearings. If the camshaft does not show excessive wear or irregularity of the surface finish, check the oil pump for damage and proper operation.
