Getting some lifter/valve noise, Bad oil pump? Options

[blu94gt]

So lately I've been noticing my car has been developing some lifter noise. The noise is mostly heard from 3-4k RPMs, and it sounds like the valves are running dry. Car has the appropriate amount of oil in it, changed regularly with the last change being just a few weeks ago. At first I thought maybe the valve clearances are off, but from past experience that would make the valves noisy all the time, right?

My other thought is maybe my oil pump is starting to go bad, and at the higher RPMs the valve aren't receiving enough oil and start to make noise. I haven't run much higher than 4k RPM so I don't know if it gets worse up higher. I also haven't run an oil pressure gauge on it, but I think I have an old Autometer one I can hook up to check with. What kind of pressure do you guys normally get?

*EDIT* forgot to add that just in the past few days I've also developed a low-idle issue. Car doesn't seem to want to idle high enough. Not sure if it's related or not, but thought it was worth mentioning. I'm going to be purchasing new NGK spark plugs and maybe wires and see if that helps, plugs have been in well over 30k miles.

This post has been edited by blu94gt: Nov 7, 2010 - 11:50 PM

[HectortheRican]

Are the valves sort of making a tweeting noise?