Chrysler Repair: low oil pressure 1990 Chrysler New Yorker, low oil pressure, chrysler new yorker

Question
QUESTION: Greetings Roland,
I have low oil pressure on the above automobile.
Can you suggest what it could be do to. I rem0ved the pan and removed the pickup to verifiy it was clear. I changed the oil.
I have had this condition for over a year. Is there a spring and ball bearing like in the old oil pumps to adjust the pressure?
Where is the bypass valve located?
Thanks in advance,
George

ANSWER: Hi George,
Did you verify the low pressure with a calibrated gauge put in place of the oil pressure light sender unit? Those can be inaccurate. Of course there may be excessive wear of various bearings, or the pressure relief valve which is on both the 2.5 or 3.0L oil pump could have a broken spring. The valve is part of the pump proper in both engines (2.5 or 3.0L, I can't be sure about the 3.3L).
Roland

---------- FOLLOW-UP ----------

QUESTION: Hey Roland,
This was checked by the mechanic originally and he said it was low. Where do I connect a 3/8" standard capillary guage?
There is a large electrical sending unit next to the oil filter but I think the hole is too large for my brass fittings? The oil goes up and down at will never mind the speed of the engine. It usually is just above the first mark .The engine sounded tight but when I let it set fora year it sounded like the rods were comming out of it and now it sounds like some small lifter noise. Do I have to remove the pump to adjust the spring and ball. If so I may as well spend $55 and install a after markett oil pump. What do you think?
Thanks for your fast response,
George

Answer
Hi George,
I got your note and evaluation. Thank you.
The Haynes manual (#25020) covers the full size Chrysler from 1988-1993 and includes a couple of pages on how to evaluate the oil pump and remove/replace it on the 3.3L engine. If you can't find a copy easily I will be pleased to xerox those pages and mail them to you. You can inspect the pressure relief spring and valve which are in the chain case cover, when you are doing that. Have you tried any measurements with an accurate gauge?
I don't have a scanner so if you want the pages from the Haynes let me know by giving a postal mail address in another evaluation.
Roland