I totally agree with JohnG. A clogged pickup screen can ruin a perfectly good engine.
How old is your engine (in terms of miles)? Back in the day, many car owners used straight-weight, non-detergent, oil. Excessive engine heat usually makes sludge by breaking down the oil.
Your oil goes through the pump BEFORE the filter. If small metal particles are in the oil, the pump will embed them in the rotors. While you are cleaning your pan and pickup tube, pull the oil pump off and inspect the rotors inside. I think you will be amazed at how messed up it can be (and still work).
Macsautoparts.com sells just the parts that wear in a kit for $19.00.
For twenty bucks, your oil pressure will be restored to 'new' condition! That's a deal!
I have a theory about all oil filters. Never depend on ANY of them. The real filtration happens when you change your oil every 3,000 miles. Most of your oil never gets filtered. Yep, that's right... that paper element can't possibly filter even half the oil that gets pumped, especially when your oil is cold. Race engines have TWO filters plumbed in parallel.
European cars (like Fiat and VW) didn't have filters in the old days, they had screens. I was shocked to learn this. Then another shocking discovery... the pump has a pressure relief valve that dumps excess pressure back to the oil pan, and that oil never sees the filter, either.
So, have you ever heard of a disgruntled buyer who returned an oil filter saying, "I want a refund because this thing didn't do its job."? I haven't either.
Change your engine oil religiously at 3k, and the filtration will be a moot issue. Here's another shocker... rear end lube: It rarely EVER gets changed, and it usually has glitter-like flakes of metal floating around in it. - Dave