99 grand voyager Knocking/Oil problem

Hi, I have a 99 grand voyager w/ 3.3L engine. About a month ago I started having problems with the oil light coming on even when it was full on oil. By removing the oil pan and looking around I found that the oil pickup unit? (small pipe thing with a screen on the end, hangs in the oil pan) was completely clogged. I cleaned it out and things were fine for about 2 weeks. Today I noticed that while idling in traffic the oil light started coming on again, when I accelerate it goes away. Also there is a knocking noise at idle, but it also goes away when at a higher RPM. Does anyone have any idea what's going on? Thanks.

Bryan

oil pump failure
pick-up tube is clogged again

To check the oil pump you'll need to connect a direct pressure gauge at the sender and read the pressure at idle and at speed. Should be a minimum of 5 psi at idle and 30-80 at speed. The knock could be any number of engine components not getting enough lubrication. A trained ear could give you more specifics.

Next to dropping the pan again a quick easy thing to try would be dump a can of engine flush in the oil. Rislone and Gunk are two companies that make it. If your fixes don't work have a mechanic look at it asap before the engine eats itself.

I bet you used carb cleaner or some other solvent to clean the screen, huh? Solvent's will wash the oil off bearings.. You should ALWAYS but a new screen...and oil pump at the same time.

Thanks for the quick replies, what Im getting is that I'm going to have to test the oil pump. You say connect the guage at the sender, is that the same thing as the oil sending unit? Sorry if thats a stupid question, I just want to be sure. Also, I cleaned the screen with gasoline, waited until it was dry but could that have anything to do with it?

Bryan

Yes, "sender" is the oil sender unit or transmitter. Not a thing wrong with being sure. I don't see a problem cleaning the screen with gas although paint thinner or degreaser would be safer.

No solvents! The only safe bet is to burn it out with a torch if you can't afford a new one.