i have been watching my oil pressure gauge get to the a on normal. eventhough it is still in the normal range i was wondering if it would be a sign of something to come. the oil is fine so i dont think it is the amount.

the engine has 217000 miles on it 4.0 Ohv 1994

Your oil gauge is not a gauge. It is an idiot light. If your oil pressure is above 5 psi (or so), the gauge will read normal. If it drops below the setpoint, it wiil go into the red. You have nothing to worry about.

As already stated, you gauge is just an analog idiot light.

It can move a little, but it has nothing to do with oil pressure (unless it reads really really really low), its usually battery cables (getting corroded) that starts to change where the oil pressure gauge reads.

~Mark

Are there other symptoms that might show up when the battery cables start to corrode. I'm asking because my oil pressure "idiot" gauge jumps a little every now and then.

could just be the alternator. Keep and eye on the voltermeter don't work about anything.

Is the oil pressure "gauge" an idiot gauge in all years? Is there a simple fix (i.e. changing the sender)?

Somewhere in the 2nd generation of Explorers they changed the design. The new design makes is so you can't convert the gauge to a real gauge.

For instructions on how to convert it, search for "fake oil pressure". There is a long thread, with pictures. But in short, if you don't have the 20ohm resister on the back of the PCB of the gauge cluster you can't convert to a real gauge.

It seems that the hardest part is finding a parts counter guy that can give you a oil pressure sending unit from a mid to late 80's ford with a gauge (the sending unit is bigger on real gauges).

~Mark