Falling oil pressure

[ThatOneGuy]

When my car gets warm and driven around the oil pressure slowly falls and makes its way to 0 and it starts dinging, telling me to check gauges but when I accelerate the pressure goes above 0 to halfway in the red. The oil is full and I already replaced the sensor so any idea what's causing this?

[96 SSEi]

hi, what weight oil are you using?- 10w 40,10w 30....

my 96 used to drop but never to 0 - when I ran with 10w 40 it seemed to steady a bit.

[ThatOneGuy]

Currently 10 30. I was running 530 but then this pressure problem arises and I switched to 1030 with no luck in solving the issue so I replaced the sensor but it only helped for a week or so.

[96 SSEi]

may be the new sender is bad- how are the wires? does anything look damaged at the connection?

[ThatOneGuy]

Wires and connection all look good, I pulled it the other day and it wasn't torn like the old one but acts the same. It doesn't effect the car it seems but I'm curious because it's annoying but not to worried.

[96 SSEi]

you may try removing sender and cleaning the part that goes into block- do this at next oil change- it may be blocked by debris

[AJT2004]

What brand of oil filter are you using? With your high mileage this could be a sign of a worn engine if regular oil changes where not done. To eliminate the easy stuff I would recommend an AC filter and switch to a 10-40 and see what happens.The next step would be to confirm oil pressure as this maybe only be a problem with the gauge cluster

[Jfridge92]

+1 on verifying pressure with a mechanical gauge. Is your motor showing any symptoms of low oil pressure, such as loud lifters, knock etc? If there aren't any audible symptoms and pressure checks out, there's probably something electrical going on. Usually when the cluster stepper motors go out, I don't believe they would cause the warning chimes to go off, so you're probably looking somewhere on the electrical path of the sender.

[ThatOneGuy]

No there aren't any audible signs of low pressure, I will definetly clean it out next change and use 10 40, hope that helps! Thanks for all the suggestions!

[haro1225]

Fram oil filters can be known to cause pressure issues, also some have reported that the AC delco senders are the most reliable ones. Some of the aftermarket ones do not last very long.

[JohnR]

If mechanical gauge confirms low pressure I'd ask how are the lower intake gaskets? Send a sample of oil out to be analyzed by a lab. Small amounts of coolant might not be visible in the oil but may be enough to wear out the bearings. I also seem to remember it to be not uncommon for a 3.8 to need a new oil pump.

[l67se]

My guess is you're gonna need a new set of rod bearings soon.
Seen this way too many times

[ThatOneGuy]

Also when the pressure hits 0 my battery gauge falls to about 10 but climbs back up when oil pressure rises. All lower gaskets were replaced about a year ago