[shorod]

Yeah, you could add an auxilliary oil pressure guage. You may be able to find an unused port that you could use for the oil pressure gauge, but expect that you will need to disconnect the OEM gauge. I'm not sure if that would screw up anything as far as the PCM monitoring it.

According to the factory service manual for a 2000 Explorer, the instrument cluster "guage" is really no more than a light. There is an oil pressure switch that causes the gauge to read "normal" with normal oil pressure or "low" with low oil pressure, but the is no chance for anything in between.

It seems the general concensus these days is that synthetic or dino oil is personal preference. Synthentic costs more, but allows you to go longer, typically, between oil changes. Conventional oil is fine if you plan to change your oil and filter on the typical 3 month, 3000 miles interval. I'm not going to address environmental arguments between dino and synthetic.

I don't think that 1 quart of transmission fluid with 4 quarts of engine oil will harm anything if you were to leave it in a bit longer, however, if the noise is not improving and you have indications the oil pressure may be low, I'd suggest you get that checked out ASAP!

-Rod