Oil pressure

I have a 1997 Murcury Sable with the 3.0 V six with 104,000 miles on it. The oil pressure light came on in the vehicle. I took it to a near by mech, he tested the sender it was fine. It is still at the mech and now the lifters have started making noise. He replaced the oil pump and that didn't solve the problem. It doesn't sound like a bearing problem or a rob problem, just lifters, the mechanic said the same thing. I made a couple phone calls and was told the problem is a gear at the bottom of a bolt that has two wires attached to it, that's located on the engine where the distributor would normally be and shouldn't take more than 45min to fix. This gear apparently has soming to do with the timing of the oil pump or somthing, this mech said it is sort of common on this engine for that to happen and that 95% of the time when you have oil pressure problems that's the issues with this motor. Is this true? Why don't more people know about this if it is.