Hello everyone, brand new to this forum, but not Rangers having had an '83 with the 2.9 purchased new for 9 years, and a '99 with the 3.0 motor for the past 10 that currently shows about 160,000 miles. Recently obtained a '94 with the 3.0 that had supposedly been sitting for a while, and had about 207,000 miles showing. After changing the oil and filter, air-filter, plugs and wires, coolant and a few hoses, truck ran strong without using a drop of oil for about 2,000 miles.

At about 3,000, oil light came on as it was about a quart low, but I didn't see any signs of major leakage. Added the quart and it continued to run strong for the next couple of days. During all of this time, the oil pressure gauge always lined up pretty much between the "o" and "r" in "normal." During the several days after adding the quart, starting hearing much more chatter from the engine, and then for the first time, last evening the gauge began hovering between the "m" and the "a," but still seemed to be running fine. Due to the mileage, the truck being new to me, and having a fairly long commute, have been watching the gauges closely, so am pretty sure this is the first time the OP needle has moved.from it's usual position.

Thoughts? Much thanks in advance.

 

Welcome to the forum

Oil Level light comes on when oil in the pan drops too low, sensor on the side of the oil pan

Oil Pressure is a different thing, Ford uses an oil pressure switch, not a sender, so either switch is open(no ground) or closed(grounded to engine)
The oil pressure gauge has a resistor on the back(in 1994) so when switch is Grounded the needle stays in "normal" range, any up and down movement is electrical voltage up and down, not related to oil pressure.
Oil switch is OPEN under 5psi, and closed over 5psi

If gauge drops to 0 then pressure is under 5psi, if it stays in "normal" range then pressure should be above 5psi
These switch do wear out

And just FYI, the N O R M A L lettering on the gauge is different on different years, so when referencing a gauges needle use 1/4, 1/3, 1/2, ect........this applies to temp, oil, fuel and battery/voltage gauges


But valve train noise IS a sign of low oil pressure, regardless of whats on the gauge.
Valve train noise will start when oil pressure is around 3psi, so gauge should be at 0 if noise is related to pressure, but switch on engine may be bad.

Oil Pressure switch on the 3.0l is on passenger side of engine at the back by the firewall, behind the head on the block, next to bell housing
It has 1 wire connected, if you take that wire off and GROUND it, then turn on the key you will see what oil gauge should show if pressure is above 5psi, it will be slightly lower than you have seen because its power is battery voltage 12.5volts
With engine/alternator started voltage jumps up to 14.5volts, try it and see, then after a few minutes running alternator should stabilize at 13.5volts

Oil can leak out or be burned in the engine, these are only two ways oil level can drop.
Check PCV Valve for signs of too much oil vapor in engine
Also check a few spark plug tips for signs of oil burning

 

Thank you very much for the reply, it helped a lot. I had scanned some of the threads about the OP gauge prior to posting, and saw reference to the gauge normal range being largely influenced by electrical voltage, but got the impression that was on more recent models. Will definitely check the switch. Thanks again!