ram oil pressure drop

Hi everyone.I have a 97 ram 1500 with a 5.9.At idle the oil pressure drops on the guage and the light flickers.As soon as I touch the throttle,The guage rises and the light goes out.The sender has been replaced with the problem remaining.The problem seems slightly worse with thicker viscosity oils and when engine is warm.I put a manual guage on and pressure at idle was around 10 psi and went up to 40 when throttle was pushed.I dropped oil pan and found some sludge in bottom and a couple small pieces of metal.Block looked fairly clean, so I replaced oil pump and reassembled.I started and found problem still existed.Engine has no noises when cold or hot except a lifter tap every once in a while.Could this be a sludge problem,main bearing, or cam bearing problem?If sludge in the oil ports, is there any way to successfully flush them without disassembly?Also does anybody know what oil pressure should be at idle.Would shimming oil pump relief valve slightly and running synthetic oil help?

Thanks, Bob

I haven't used any yet, but I've hear lots of good things about "seafoam". before an oil change, put about 1/2 can into the crank case, run the engine for a few minutes, then change the oil like normal. apparently it (seafoam) breaks down any sludge accumulation, and lets it come out with the oil.
here's their website, http://www.seafoamsales.com/motorTuneUp.htm
but I think you can pick the stuff up at most auto parts stores.

however, if a good cleaning dosn't help, I'd imagine that the oil pump is getting worn out, I thin your oil preasue is supposed to be around 30psi at idle when warm.

Thanks for the suggestion, I will give it a try.

i have a 94 ram 1500 5.2 liter... same problem.. replaced the sender unit.. no change.. now i have 170,000 miles on my truck.. should i use that seafoam or not ?

It certainly wouldn't hurt.

yeah but i heard you shouldnt use that stuff on old trucks...

94 is old? And who told you that?

the only way it would hurt the engine is if you left it in the oil to long. seafoam breaks down oil, that's why you put it in the crank case right before an oil change. you do NOT want to drive around with the stuff in there.
also, if the engien has a lot of miles, you could develop some leaks, but that's only because chances are that with a lot of miles, the seals are already wearing out, and have some "sludge" that is keeping them from leaking. well, the seafoam is going to break down that sludge, and the seals may start leaking. but some people have the same problem when switching from dino oil to synthetic, so really it's not that big of a deal.

Good, because I just bought a can of it for 13 bucks and I wasn't gonna use it if it was bad...

yeah the guy at napa said dont use motor flush cuz it might cause the rings and other seals to leak.

I had the same kind of problem going on with my 2001 Ram. I also had a 5.9 in it. I ran it like this with what i thought was a lifter tappijng for about two years and then one day the wife was driving it back from shopping because I had to drive the other car and the pressure dropped out more than regular and then I went to pick up our camper from storage and the pressure dropped out all the way and i just got done putting in a different engine today because I spun a couple of rod bearings. If i was you I would check your rod brgs. for slop because this seems to be what caused my problem and I also thought it was just a lifter tapping when in essence I think it was a sloppy rod brg. that finally gave up the ghost. From my experience the only thing that will cause oil pressure to fluctuate like that is a bad oil pump and/or bad brgs. wether it be cam, rod or main. the more clearance you have the lower pressure you will have. Good Luck