My 96 bonne se has 85k miles, The other day chime went off and oil pressure was at the edge of the red mark in drive. Would go up to about 20 of idle. was near home and went into garage. I left for 4 days and new when I got home I had work to do. ALos after 4 days of thinking and questions, I'm thinking main bearings.
some history Upper and lower intake gaskets were done at 50k in 2001 and upper manifold replaced later at 60k in 2003 with upper gaskets because of exterior coolant leak at MAF sensor/uim Coolant is prestone dex always filled above full mark and changed every 4 yrs, 185 t stat with no coolant loss.
current synthetic supertech had about 3000 miles with supertech filter. Oil pressure sender was about 2 years old.4from autozone. Car is used to take my little ones to school and athetics with about 4-5K/yr
No ticking on engine and seemed fine. I am thinking about scenarios oil/filter failure, diluted oil from possible fuel injector leakdown, bad pressure sending unit, bad main bearings.
After reading many posts here. I shopped quickly for a 1 night repair at my shop. I work for a landscape company repairing various power equipment. Picked up mechanical oil gauge test set cheap at harbor freight for $10, Valvoline 10/30 full synthetic, Ac/delco PF47 (the good one with the small holes inside), and a new ac/delco pressure sending unit.
I took car to work and put on lift. Removed pressure sender and noticed oil inside connector plug indicating sender was leaking internally and most likely the problem. Connected mechanical gauge with old oil/filter, 65 psi cold at idle. 80 psi at 1850 rpm. At temp idle park 45 psi and at 1850 was around 65.
In drive at idle hot it was never below 35 psi but gauge was a bit shaky at idle bouncing 2-3 psi burt still above 35 psi. After that relief I changed oil and filter and checked pressures again. Readings were basically the same at idle in drive. Sender was the culprit and compaared it to the new ac delco. The Ac had larger oil orifice and inside the connector area the mold mark was centered and clean. the old auto zone sender had off center mold mark with plastic flashing inside connector area and oil orifice was noticeable smaller.
My advice is spend money on good AC/DElCo parts. In the long run it saves money and time. My next maintenace will be brakes. I will get AC/delco rotors and pads. No cheap rotors this time. I hope that my long rant here is helpful to someone with similiar issues. I'd also like to thank you for all the great info this site provides. I wish my other cars forum had this kind of information.Thx for letting me bend your ear.