Fluctuating oil pressure

[JohnStra]

Hi folks. First post on this site. I want to make sure I'm taking the right steps to determine what's going on with my '92 V-6 truck. My oil pressure fluctuates, according to my guage. On startup, pressure reads normal both at idle and running at higher RPM. After a variable period of time, the guage reading starts slowly dropping. It will eventually go all the way down to nothing and then decide after some random period of time to come back up. I've ordered a new sender just to rule that out.

The reason this worries me is I just had to replace a head due to a siezed cam - the front journal was totally ruined. It looks like it quit oiling. The cam on the other side shows no damage at all though, so it looks like the oiling problem was localized. Just concerns me that I might have problem with the oil pump even though my mechanic says he really doesn't think so.

Last piece of info is that it sounds like one of my idler bearings is getting ready to go. When cold, makes a loud whine. I don't see how, but I want to know if a problem with an idler bearing could somehow cause an oiling problem.

Thanks for any information.

-john

[justin22]

how long since your last oil change, what type, and grade of oil, where is the oil reading on your dip stick.

did you change the oil last time, or did you have it done at a shop

[JohnStra]

Last oil/filter change (before I lost the cam & head) was October, had it done at a shop. Prior to that I'd done all my own maintenance. Guage was already fluctuating at that time cause it was actually at the shop the first time I ever saw low - before they touched it. It had Quaker State 10W-30 in it when the cam went. The mechanic that replaced the head (I just got it back this week) also put 10W-30 in it. Dip stick says good.

[JeremyH]

Sounds like oil sending unit to me.....